Patent Description:
Various types of devices may utilize switches, such as solid state switches. A switch may be controlled from a power domain of the device. The power domain may be isolated with respect to a region of the device at which the switch is located. Isolation may be achieved by using an optical isolation barrier. The optical isolation barrier is positioned within the device between a first side of the device comprising the power domain and a second side of the device comprising the switch. In order to control the switch through the optical isolation barrier, information and/or energy has to be sent across the optical isolation barrier. Unfortunately, optically isolated switches may lead to and imply high manufacturing costs and may enable only limited gate drive capability with regard to achievable drive voltage and current. Document <CIT> relates to an isolated gate driver device for a power switching device having a plurality of transistors that includes a primary circuit having a voltage source of a first voltage potential. The primary circuit constantly switches the voltage source to generate first and second load signals based on control signals received from a microcontroller. The first load signal is modulated at a first frequency for enabling the transistors, and the second load signal is modulated at a second frequency, different from the first frequency, for disabling the transistors. A plurality of high frequency transformers corresponding to each of the transistors is coupled to the primary circuit. The transformers have a primary side for receiving one of the first and second load signals and a secondary side for transforming the one of the first and second load signals into corresponding signals at a second voltage potential. A secondary circuit coupled between each of the transformers and each of the corresponding transistors provides a bias power supply to each of the transistors at the second voltage potential. The secondary circuit also enables and disables each of the transistors based on the first and second load signals.

Many existing solutions, such as alternatives to optical isolation using galvanic isolation based on capacitive coupling or transformer coupling that both require integration capabilities, have various drawbacks. One such drawback is the requirement of additional specific supply pins at one or more sides of an isolation barrier. Another drawback is the inability to integrate an isolation barrier and a solid state switch into a same package. Yet another drawback is the inability to provide pin to pin compatibility with other isolation devices meant for driving solid state switch, such as optocouplers or solid state relays, which typically do not require any specific power supply pin at the isolation side where the drive switch is located. Furthermore, existing isolation solutions are not always able to generate voltages on a secondary side of the isolation barrier (e.g., the second side at which the switch is located) that are higher than voltages at a primary side of the isolation barrier (e.g., the first side where the power domain is located). This greatly constrains and limits the types of switches that can be utilized because such switches would have to have a threshold voltage compatible with an input voltage range, which may be prohibitively low in relation to voltages used to operate the switches. One drawback for capacitive isolation is common mode transient immunity between the two sides of an isolation barrier, which can quickly move their potential in opposite directions. Although some products may combine one or more of these isolation solutions and/or features thereof, there is no current product that addresses all of the aforementioned deficiencies at the same time while providing integrated protection features, safety countermeasures, and/or fault communication.

This Summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

In an example of the techniques presented herein, an apparatus is provided. The apparatus comprises an energy transfer device configured to supply power from a primary side of an isolation barrier through the isolation barrier to a secondary side of the of the isolation barrier to directly drive a gate of a switch for controlling output of the switch at the secondary side. The apparatus comprises a monitoring component. The monitoring component is configured to monitor an operating state of the switch, and evaluate the operating state to determine whether a fault has occurred.

In an example of the techniques presented herein, an apparatus is provided. The apparatus comprises an energy transfer device configured to supply power from a primary side of an isolation barrier through the isolation barrier to a secondary side of the of the isolation barrier to power an isolated gate driver to drive a gate of a switch for controlling output of the switch at the secondary side. The apparatus comprises a monitoring component. The monitoring component is configured to monitor an operating state of the switch, and evaluate the operating state to determine whether a fault has occurred.

In an example of the techniques presented herein, a method is provided. The method includes controlling a monitoring component of an isolated power converter to determine an operating state of a switching component associated with a secondary side of an apparatus. The switching component is driven based upon power transferred from a primary side of the apparatus through an isolation barrier to the secondary side. The operating state is evaluated to determine whether the switching component has experienced a fault. In response to the switching component experiencing the fault, a countermeasure is implemented.

In an example of the techniques presented herein, an apparatus is provided. The apparatus includes a means for controlling a monitoring component of an isolated power converter to determine an operating state of a switching component associated with a secondary side of an apparatus. The switching component is driven based upon power transferred from a primary side of the apparatus through an isolation barrier to the secondary side. The apparatus comprises a means for evaluating the operating state to determine whether the switching component has experienced a fault. The apparatus comprises a means for implementing a countermeasure in response to the switching component experiencing the fault.

To the accomplishment of the foregoing and related ends, the following description and annexed drawings set forth certain illustrative aspects and implementations. These are indicative of but a few of the various ways in which one or more aspects may be employed. Other aspects, advantages, and novel features of the disclosure will become apparent from the following detailed description when considered in conjunction with the annexed drawings.

The claimed subject matter is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the claimed subject matter.

Within the field of electronics, a device comprises a switch that is to be controlled from a region of the device, such as a power domain region of the device, which is to be isolated from the switch. The ability to operate the switch is improved by using electrical isolation, such as by utilizing a capacitive coupling, a transformer such as a core or coreless transformer or any other type of transformer, or other electrical isolation barrier. The electrical isolation barrier can be used in a manner that does not introduce topological differences or penalties in the device, and thus the device can be easily swapped with other existing devices without introducing noticeable differences, such as in device size, package, or pinout. For example, pin to pin compatibility is provided because there is no need for additional pins otherwise used to provide a specific power supply on either side of the electrical insolation barrier.

An energy transfer device is capable of transmitting an adequate amount of energy from a first side of the device (e.g., a side within which the power domain region is located), through the electrical isolation barrier, to a second side of the device within which the switch is located. The energy is transferred to the secondary side of the isolation barrier element during a sequence of switching cycles applied to the primary side of the isolation barrier element, so that the switch, such as a solid state switch, can be properly and reliably turned on with sufficient speed and without the need of additional energy from the secondary side. Furthermore, power to the switch is safely turned off with sufficient speed without having to transfer energy across the electrical isolation barrier and without the need of external components.

The techniques and apparatuses provided herein are capable of providing power transfer, gate drive, and/or monitoring solutions. In some embodiments, these capabilities may be part of a single chip solution. Power transfer is provided utilizing isolated power converters that can power a switch across an isolation barrier. Direct and/or indirect gate drive is provided utilizing isolated gate drivers or solid state relays with or without the integration of protection functions, independent safety countermeasures, and/or fault communication to a primary side of a device. Isolated monitoring solutions are provided utilizing isolation amplifiers or comparators, isolated analog to digital converters, non-isolated amplifiers, and/or analog to digital converters located on a secondary side and coupled to analog or digital isolators.

In some embodiments, a direct gate drive feature is provided. This direct gate drive feature relates to the integration of secondary power supply generation with voltage levels higher than those at a primary side together with a gate drive function. The gate drive function may be provided for solid state relay applications that relate particularly to applications where switching speeds and turn ON times of the driven switches are not particularly fast, such as switching frequencies less than <NUM>. Hence, in these applications, the power conversion function and the generation of the secondary side supply can coincide with that of the gate drive of the switch. The gate of the switch is directly controlled by the output of a power converter. In this way, if the power conversion is started from the primary side, this translates directly to the gate drive at the secondary side without using a specific gate driver in-between. When the power converter is restarted from the power converter's turn off condition, the power converter's own start up time is reflected directly on the turn ON time of the switch, and thus this direct gate drive feature may be suitable for relatively slower switching. Because the switching speed may not be a key focus of solid state relay applications, the power transfer strength may not necessarily be a key parameter where the higher the transferred power, the faster the turn ON of the controlled switch. Hence, for solid state relays, a wide variety of isolated power converters can be considered, possibly preferring some due to chip integration advantages (complexity and size) rather than power transfer capability or efficiency. In this way, the direct gate drive feature powers a switch with an output voltage of a power converter.

In some embodiments, an indirect gate drive feature is provided. This indirect gate drive feature enhances the gate drive function for allowing faster switching speeds and higher frequencies such as frequencies greater than <NUM>. This is achieved by decoupling the isolated power conversion (and secondary supply generation) function from that of the isolated gate drive. This decoupling is accomplished by combining a transformer based isolated power converter and an isolated gate driver on a same chip (either monolithically or in a System in Package (SiP)). This transformer based isolated power converter offers voltage conversion ratios larger than <NUM> so that switches can be driven at the secondary side, where a drive voltage of a switch is higher than a voltage class of the controller which controls the switching at the primary side. Voltage conversion ratios larger than <NUM> are possible utilizing various isolated power conversion topologies, such as a flyback converter and/or resonant converters of different kinds where the secondary/primary transformer winding ratio is larger than <NUM>. While the secondary power supply may be constantly available and once the power converter is started and operated independently of the isolated gate driver, the isolated gate driver coupled to the controller at the primary side can operate independently and control a gate of the connected switch with higher switching frequency and speed. With switching speed as a focus, power transfer strength and efficiency are relevant parameters. Hence, transformer based integrated isolated power converters may be a suitable choice. In this way, the indirect gate drive feature relates to a combination of an integrated transformer based isolated converter with voltage conversion ratios larger than <NUM> and an isolated gate driver.

With the integrated isolated power converter operating on its own, independent on whether the integrated isolated power converter is coupled with or decoupled from the switch gate drive, it is possible to start the power conversion once and to keep it active for generating the secondary supply throughout system operation.

In some embodiments, a safety monitoring and/or related countermeasures feature is provided. The secondary power supply generated by the integrated isolated power converter can also be used to supply other functions, which can monitor the safety status at the secondary side, for example. These other functions can be implemented independent of whether an integrated isolated gate driver is added for faster switching, a gate of a switch is directly coupled to the secondary power supply, and/or if a switch is not connected/controlled at all. The safety functions may be, for example, monitoring to determine whether a critical temperature threshold, a current threshold, and/or a voltage threshold has been reached either at a switch driven by either the isolated power converter or by an isolated gate driver combined with the isolated power converter, or at any other component located at the secondary side.

In the event that the monitoring functions detect a fault, countermeasures can be promptly determined and applied directly at the secondary side without waiting for any reporting delay to the controller at the primary side and delay waiting on a decision from the controller at the primary side. For example, where a switch is being driven either directly by the isolated power converter or by the isolated gate driver, detecting a fault condition can imply that this switch is turned off. In this way, this safety monitoring and/or related countermeasures feature provides for the integration of safety monitoring functions and possibly related countermeasures together with an isolated power converter for their supply. In some embodiments, this safety monitoring and/or related countermeasures feature may be separately implemented (e.g., implemented without the integration of other features) with its independent secondary power supply, thus allowing safety monitoring of otherwise supplied secondary power domains even before the secondary power domains are energized.

In some embodiments, a reporting feature is provided. The reporting feature is implemented to report information to the controller operating on the primary side in order to inform the controller of any known critical conditions that were met at the secondary side and/or whether any countermeasures were applied. For example, the reporting feature may be implemented to flag a fault, detected at the secondary side, to the primary side and/or whether any countermeasures were implemented for the fault. In some embodiments, a fault may be reported by changing a current or a voltage at an output pin. In some embodiments of flagging the fault, a pin at the inside side may change a logical state based upon detection of the fault or in reaction to the fault. In some embodiments, an additional isolation barrier may be utilized as part of the reporting features. In this way, this reporting feature relates to the integration of communication of detected faults and/or implemented countermeasures from the secondary side to the primary side.

In some embodiments, an integrated power driven switch feature is provided. The integrated power driven switch feature relates to integrating a switch that is to be driven with an arrangement used to generate a secondary power supply used to control a gate of the switch.

Various advantages are achieved by combining/integrating one or more of these features together, such as integrating the integrated power driven switch feature, the reporting feature, and/or the safety monitoring and/or related countermeasures feature into an arrangement having either the direct gate drive feature or the indirect gate drive feature. The combination/integration of one or more of these features provides advantages related to reduction of materials (BOM), system size, cost, complexity, and/or overall system safety in terms of fault response.

An embodiment of providing power transfer, gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier is illustrated by an exemplary method <NUM> of <FIG> and further described in conjunction with <FIG>. An apparatus, such as device <NUM> of <FIG>, comprises an isolation barrier <NUM> that isolates a primary side <NUM> of the device <NUM> from a secondary side <NUM> of the device <NUM>. In some embodiments, the device <NUM> may correspond to an isolated power converter. The isolation barrier <NUM> may comprise an electrical isolation device that provides electrical isolation between the primary side <NUM> and the secondary side <NUM> of the device <NUM>. In an embodiment, the isolation barrier <NUM> comprises a transformer, such as a coreless transformer or a core transformer (e.g., transformer <NUM> of <FIG>). In an embodiment, the isolation barrier <NUM> comprises a capacitive coupling. The isolation barrier <NUM> provides galvanic isolation between the primary side <NUM> and the secondary side <NUM>.

The primary side <NUM> comprises an input source <NUM>. The input source <NUM> may be associated with an input power domain that supplies an input voltage for the primary side <NUM>. The primary side <NUM> may comprise one or more input switches <NUM> (e.g., a first input switch SW1A <NUM>, a second input switch SW1B <NUM>, a third input switch SW2A <NUM>, and a fourth input switch SW2B <NUM> of <FIG>). The primary side <NUM> comprises an energy transfer device <NUM> configured to operate the one or more input switches <NUM> to perform a plurality of switching cycles for transferring energy through the isolation barrier <NUM> to the secondary side <NUM> for controlling a switch <NUM> located at the secondary side <NUM> of the device <NUM>. The plurality of switching cycles correspond to a sequence of switch cycles where energy transfer is either active or inactive. The energy transfer device <NUM> may operate the one or more input switches <NUM> according to a frequency (e.g., a switching frequency) and a duty cycle to transfer the energy through the isolation barrier <NUM> during a switching cycle for activating the switch <NUM>. In an embodiment, an On-Off Keying technique is utilized by the energy transfer device <NUM> to perform a plurality of switching cycles for transferring the energy through the isolation barrier <NUM> for operating the switch <NUM>.

Accordingly, the one or more input switches <NUM> are operated according to the frequency and the duty cycle to transfer the energy through the isolation barrier <NUM> during a sequence of switching cycles for activating the switch <NUM>. In an embodiment, the On-Off Keying is applied by operating the one or more input switches <NUM> according to a determined frequency and duty cycle. The frequency may be set to a high enough value in order to limit a current flow through a primary winding of the isolation barrier <NUM> (e.g., a transformer) within a switching cycle. Depending on whether a flyback converter or a voltage multiplier is utilized as a voltage conversion device <NUM> at the secondary side <NUM>, different duty cycles may be utilized. For example, the duty cycle may be set to <NUM>% for the voltage multiplier where energy is driven by the energy transfer device <NUM> according to a push and pull manner. In this example, the switching cycle comprises a first phase where input current flows from a top terminal of the isolation barrier <NUM> to a bottom terminal of the isolation barrier <NUM>. The switching cycle comprises a second phase where input current flows from the bottom terminal to the top terminal. For the flyback converter, the duty cycle may be set based upon the switching frequency so that an inductance across the isolation barrier <NUM> does not reach a saturation point or reliability issues do not occur.

If the one or more input switches <NUM> are kept off by the energy transfer device <NUM>, then no energy transfer takes place. If the one or more input switches <NUM> are turned on by the energy transfer device <NUM>, then energy is transferred through the isolation barrier <NUM> to the secondary side <NUM> for turning on the switch <NUM>. In this way, a sequence of switching cycles are performed where energy transfer is either active or inactive.

In some embodiments, the device <NUM> comprises the voltage conversion device <NUM> located at the secondary side <NUM> of the device <NUM>. The voltage conversion device <NUM> may comprise a flyback converter, a voltage multiplier such as a Cockroft-Walton voltage multiplier, or other voltage conversion device. The voltage conversion device <NUM> may be configured to convert the energy transferred by the energy transfer device <NUM> from the input voltage associated with the input source <NUM> to an output voltage capable of controlling, such as turning on, the switch <NUM>. In an embodiment, the voltage conversion device <NUM> may convert the input voltage to a relatively higher voltage as the output voltage capable of turning on the switch <NUM> (e.g., turning on a gate of a solid state switch). In this way, various types of switches <NUM> can be used that could otherwise not be operable/compatible with the relatively lower input voltage associated with the input source <NUM>. The voltage conversion device <NUM> outputs the output voltage when the energy transfer by the energy transfer device <NUM> is active. In this way, energy is converted from the input voltage of the primary side <NUM> to the output voltage to control the switch <NUM> when the energy transfer is active.

The device <NUM> comprises a pulldown device <NUM>, such as a passive turn off device, at the secondary side <NUM> of the device <NUM>. In an embodiment, the pulldown device <NUM> comprises a depletion MOSFET (e.g., a depletion n channel MOSFET or a depletion p channel MOSFET). When no energy transfer is being performed by the energy transfer device <NUM> to otherwise activate the switch <NUM>, the pulldown device <NUM> passively (e.g., without the need for power to be supplied to the pulldown device <NUM>) deactivates the switch <NUM> to turn off the switch <NUM>. For example, when there is no energy transfer, capacitors on the secondary side <NUM> are discharged, and thus a source and a gate of the pulldown device <NUM> are at a same/similar potential, which, in a depletion MOSFET, creates a conduction channel between the source and the drain of the pulldown device <NUM>, in some embodiments. In some embodiments, the pulldown device <NUM> may be a depletion MOSFET, a p-MOSFET or other device. The conduction channel acts like a resistor, sized according to dimensions of the pulldown device <NUM>, which applies a turn off strength between a gate and a source of the switch <NUM> to turn off the switch <NUM> (e.g., by shorting the gate of the switch <NUM> to the source of the switch <NUM>). In this way, the pulldown device <NUM> passively deactivates the switch <NUM>, without being actively driven with power, when no energy transfer is being performed.

The pulldown device <NUM> may be disabled from passively deactivating the switch <NUM> when the energy transfer is active. In an embodiment, a charge pump <NUM> (e.g., a positive charge pump for the depletion p channel MOSFET or a negative charge pump for the depletion n channel MOSFET) may be utilized to disable the pulldown device <NUM> from passively deactivating the switch <NUM> when the energy transfer is active. With the depletion n channel MOSFET, the negative charge pump is utilized to actively drive down a gate of the depletion n channel MOSFET using a negative voltage to disable the depletion n channel MOSFET from passively deactivating the switch <NUM> when the energy transfer is active. In this way, the pulldown device <NUM> is disabled from passively deactivating the switch <NUM> when the energy transfer is active. When the energy transfer is inactive, a load at an output of the negative charge pump discharges the negative voltage to enable the depletion n channel MOSFET to passively deactivate the switch <NUM>. When there is no switching activity, the negative charge pump is inactive. In this way, the pulldown device <NUM> is enabled to passively deactivate the switch <NUM> when the energy transfer is inactive.

In some embodiments, the energy transfer device <NUM> is configured according to a direct gate drive feature to power the switch <NUM> using an output voltage from the voltage conversion device <NUM>. That is, the energy transfer device <NUM> is configured to supply power from the primary side <NUM> of the isolation barrier <NUM>, through the isolation barrier <NUM>, to a secondary side of the isolation barrier <NUM> to directly drive a gate of the switch <NUM> for controlling output of the switch <NUM> at the secondary side <NUM>. In some embodiments, energy transfer device <NUM> is configured according to an indirect gate drive feature to supply power through the isolation barrier <NUM> to power an isolated gate driver that drives the gate of the switch <NUM> for controlling the output of the switch <NUM> at the secondary side <NUM>. An isolated power converter (e.g., a flyback converter, a resonant converter, etc.) may be configured to provide a voltage conversion ratio larger than <NUM> for driving the gate of the switch <NUM>.

In some embodiments, the switch <NUM> may be internal with respect to the device <NUM>, as illustrated by <FIG>, while in other embodiments, the switch <NUM> may be external to the device <NUM>. In some embodiments, the switch <NUM> and the device <NUM> may be arranged in a multi-die package.

In some embodiments, a monitoring component <NUM> may be configured to provide integration of a safety monitoring and/or related countermeasures feature for the device <NUM>. In some embodiments, the monitoring component <NUM> may be integrated into the secondary side <NUM> of the device <NUM>. In some embodiments where the isolation barrier <NUM> is a transformer, the monitoring component <NUM> may be powered from energy from a secondary winding of the transformer. The monitoring component <NUM> may implement protective functions in order to provide the safety monitoring and/or related countermeasures feature for the device <NUM>. In an example, the monitoring component <NUM> may implement the protective functions to monitor an operating state of the switch <NUM> or other component, such as by measuring current, temperature, voltage, and/or other operational information of the switch <NUM> or other component. In this way, the monitoring component <NUM> of the isolated power converter is controlled to determine the operating state of the switch <NUM> (e.g., a switching component associated with the secondary side <NUM> of the device <NUM>), during operation <NUM> of method <NUM>.

During operation <NUM> of method <NUM>, the monitoring component <NUM> is controlled to evaluate the operating state to determine whether a fault has occurred. For example, the monitoring component <NUM> may implement the protective functions <NUM> to compare a measured current, a measured temperature, a measured voltage, or other information of the operating state against one or more thresholds to determine whether the one or more thresholds have been exceeded. In response to the monitoring component <NUM> determining that the switch <NUM> or other component has experienced a fault, a countermeasure may be implemented using the protective functions <NUM> of the monitoring component <NUM>, during operation <NUM> of method <NUM>. In an example of implementing the countermeasure, the monitoring component <NUM> may utilize the protective functions <NUM> to turn off the switch <NUM>. For example, the pulldown device <NUM> at the secondary side <NUM> may be used to turn off the switch <NUM>.

In some embodiments, the monitoring component <NUM> is configured to provide integration of a reporting feature for the device <NUM>. In an example, the monitoring component <NUM> may transmit a signal to the primary side <NUM>, such as to a fault manager <NUM>, to indicate that the fault of the switch <NUM> was detected. In an example, the monitoring component <NUM> may transmit a signal to the primary side <NUM>, such as to the fault manager <NUM>, to indicate that the countermeasure was implemented. In this way, the monitoring component <NUM> transmits a signal to indicate that the fault was detected and/or that the countermeasure was implemented, during operation <NUM> of method <NUM>. The monitoring component <NUM> may transmit the signal to indicate the operating state detected by the monitoring component <NUM>, which may be indicative of other information than a detected fault or countermeasure performed. In some embodiments, the signal is transmitted through the isolation barrier <NUM> such as by shorting a secondary winding of the isolation barrier <NUM>. This is detected at the primary side <NUM> as an increase in current consumption. The signal may also be transmitted through a different isolation barrier supporting communication from the secondary side <NUM> to the primary side <NUM>, through the use of a buffer capacitor used as an energy reservoir during the secondary to primary side fault information transmission, to compensate for the possibly limited power availability at the secondary side, etc. In some embodiments, the fault manager <NUM> may be configured to suspend the supply of power to the secondary side <NUM> for a time duration, provided that this interruption in the power transfer does not impair the functionalities at the secondary side, so that the signal can be received during the time duration through the isolation barrier <NUM> from the monitoring component <NUM>. In some embodiments, the fault manager <NUM> is located at the primary side <NUM>, and is configured to implement an action in response to receiving the signal from the monitoring component <NUM> that the fault was detected. In some embodiments, the fault manager <NUM> may be configured to translate the fault communication into a signal, which a µC on the primary side can acquire (e.g. a logic signal).

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. The apparatus <NUM> comprises a transformer <NUM> that operates as the isolation barrier to isolate, such as electrically isolate, a primary side <NUM> of the apparatus <NUM> from a secondary side <NUM> of the apparatus <NUM>. The transformer <NUM> comprises a primary side <NUM> connected to the primary side <NUM> of the apparatus <NUM> and a secondary side <NUM> connected to the secondary side <NUM> of the apparatus <NUM>. The transformer <NUM> provides for electrical isolation between the primary side <NUM> and the secondary side <NUM> of the apparatus <NUM>.

The apparatus <NUM> utilizes a voltage multiplier <NUM> (e.g., a Cockroft-Walton multiplier) as a voltage conversion device to convert energy from an input voltage of the primary side <NUM> (e.g., energy transmitted from supply <NUM> through an isolation barrier to the secondary side <NUM>) to an output voltage to control a switch <NUM>. The voltage multiplier <NUM> comprises one or more stages. Each stage comprises a diode and a capacitor/capacitance (e.g., capacitor CP1 and diode D2 as a first stage, capacitor CP2 and diode D3 as a second stage, capacitor CP3 and diode D4 as a third stage, etc.). The voltage multiplier <NUM> converts the input voltage to the output voltage, which may be a higher voltage than the input voltage in order to turn on the switch <NUM>.

The apparatus <NUM> may comprise one or more input switches located at the primary side <NUM>, such as the first input switch SW1A <NUM>, the second input switch SW1B <NUM>, the third input switch SW2A <NUM>, and the fourth input switch SW2B <NUM>, that are controlled by On-Off Keying to perform a sequence of switching cycles to transfer energy from the primary side <NUM> to the secondary side <NUM> for controlling, such as turning on, the switch <NUM> at the secondary side <NUM>.

The one or more input switches are operated in a manner to drive the primary side <NUM> of the isolation barrier (e.g., the primary side <NUM> of the transformer <NUM>) in a push and pull manner. During a first phase of a switching cycle, an input current flows from a top terminal of the isolation barrier (e.g., a connection on the primary side <NUM> to a top terminal of the primary side <NUM> of the transformer <NUM>) to a bottom terminal of the isolation barrier (e.g., a connection on the primary side <NUM> to a bottom terminal of the primary side <NUM> of the transformer <NUM>). In particular, the top terminal is pulled up and the bottom terminal is pulled down. Capacitor CP1, capacitor CP3, and capacitor CP5 are charged through diode D2, diode D4, and diode D6, while diode D3 and diode D5 are reverse biased. During a second phase of the switching cycle, the current flows from the bottom terminal to the top terminal of the isolation barrier. In particular, the top terminal is pulled down and the bottom terminal is pulled up. Capacitor CP2 and capacitor CP4 are charged through diode D3 and diode D5, while diode D2, diode D4, and diode D6 are reverse biased. A duty cycle of <NUM>% may be set for symmetry. A switching frequency may be set during each phase to a frequency value that does not cause the insolation barrier to reach/exceed saturation and/or cause reliability issues.

A passive turn off device <NUM> (e.g., depletion NMOS DpN), a diode DR <NUM> associated with a voltage rectifier, a buffer capacitor <NUM>, a monitoring component <NUM>, functionality for activating the passive turn off device <NUM> and deactivating the switch <NUM> in the event a particular condition is detected (e.g., a current, voltage, or temperature exceeding a threshold), and a signal output <NUM> for communicating to e.g. an outside controller are integrated into the secondary side <NUM> of the apparatus <NUM> as a solid state relay application. The monitoring component <NUM> may correspond to sensors used to monitor internal parameters or monitor system and application parameters of external components such as current flowing in the switch <NUM> (e.g., measured by external monitoring component Rs <NUM>) or temperature of the switch <NUM> (e.g., measured by external monitoring component NTC <NUM>) that is external to the apparatus <NUM>. In this embodiment, the switch <NUM>, the external monitoring component Rs <NUM>, and the external monitoring component NTC <NUM> are external to the apparatus <NUM>, while other parameters may be internally monitored by the monitoring component <NUM>. In other embodiments, the switch <NUM> and/or monitoring components may be integrated into the apparatus <NUM>. In some embodiments, the signal output <NUM> for fault signaling may be located at the secondary side <NUM>. The passive turn off device <NUM> may be used to perform a countermeasure such as to turn off the switch <NUM>.

In some embodiments, part of the power transferred to the secondary winding of the transformer <NUM> (or to the secondary side of another isolation barrier such as a capacitive barrier) is used to supply some monitoring components or sensors, such as monitoring component <NUM>, through a dedicated rectifier (Diode DR <NUM>, buffer capacitor CBUF <NUM>). The power delivered to a monitoring component may not suffer from a power bottleneck of a voltage multiplier, making the power consumption constraints of the monitoring components less demanding. The monitoring component <NUM> may include references, amplifiers, filters, comparators and other circuits to condition sensed internal or external signals and to compare them with thresholds to decide whether conditions of operating states are critical for the switch <NUM>. If a condition is critical, then a decision can be made for deactivating the switch <NUM> by activating a turn-off device, such as the passive turn off device <NUM> (e.g., depletion NMOS DpN) or another similar device that implements the same functionality (e.g., an active device in parallel with a passive device), for example. This can be achieved by sending a suitable current through RG <NUM> so that the gate of passive turn off device <NUM> can be brought above a threshold voltage. If that injected current is absent, the gate of passive turn off device <NUM> is pulled down through DN <NUM>. Upon applying this countermeasure to the switch <NUM>, a signal may be transmitted to the signal output <NUM>. In some embodiments, the voltage multiplier may be exchanged with another power converter type to achieve higher power transfers. In this case, the power supply to the monitoring components (sensors) may be derived from the output of that power converter.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. Apparatus <NUM> is similar to the apparatus <NUM> of <FIG>, along with the addition of a reporting feature for fault communication to the primary side <NUM>. This may be achieved by adding a second transformer <NUM>, a related transmitter <NUM>, and a related receiver <NUM> for signal transfer. The transmitter <NUM> may drive a secondary side of the second transformer <NUM> with sufficiently high frequency pulses (e.g., a carrier or a modulated carrier) to indicate that a fault is detected. The transmitted pulses, carrier or modulated carrier, may be detected by the receiver <NUM> at the primary side <NUM> so that the fault condition at the secondary side <NUM> is signaled through a fault output pin <NUM> on the primary side <NUM>. Pulse polarity or carrier modulation index may be varied to encode different fault events detected (e.g., temperature exceeding a threshold, current exceeding a threshold, voltage exceeding a threshold, etc.). In order to sustain the current consumption of the fault transmission from the secondary side <NUM>, an external buffer capacitor CBUF <NUM> may be utilized (e.g., a possible internal buffering capacitor after diode DR <NUM> may also be used, but is not illustrated in this embodiment). This buffer capacitor CBUF <NUM> is charged up to a sufficient voltage level during normal operation, while no fault is present or before activating the integrated safety monitoring sensors (e.g., sensors used by the monitoring component <NUM>) at the secondary side <NUM>, before a fault transmission takes place.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. Apparatus <NUM> is similar to the apparatus <NUM> of <FIG>, along with the addition of a reporting feature for fault communication to the primary side <NUM> and without the secondary side <NUM> comprising a driven switch (e.g., switch <NUM>), sensing pins, and fault output. This is achieved with a single isolation transformer <NUM>, which is also used for power transfer. When a countermeasure is implemented upon fault detection to switch off a controlled switch by means of the passive turn off device <NUM> (e.g., depletion NMOS DpN), sustaining the power transfer across the transformer <NUM> through the voltage multiplier is not actually necessary. Hence, a secondary winding of the transformer <NUM> may be short circuited through a switch SWF <NUM>. This will cause an increase in current consumption at the primary side <NUM>, which may be detected by a suitable threshold comparator in a fault sensor <NUM> so that the fault condition can be signaled at a dedicated pin <NUM>. A diode <NUM> in series to the drain of the switch SWF <NUM> is used to ensure correct functioning in normal operation. If the diode <NUM> is absent, a body diode of the switch SWF <NUM> would short the secondary winding of the transformer <NUM> in the case that this is under negative bias. This may prevent correct functioning of the arrangement used for deactivating the passive turn off device <NUM> (e.g., depletion NMOS DpN where DN would not sufficiently pull down the gate of DpN).

In order to sustain the current consumption of the sensors of the monitoring component <NUM> and the arrangement which switches off the controlled switch while the secondary winding is shorted and unable deliver power, an external buffer capacitor CBUF <NUM> may be used. Alternatively, a buffer capacitor may also be integrated into the apparatus <NUM>. This buffer capacitor is charged up to a sufficient voltage level, during normal operation while no fault is present or before activating the integrated safety monitoring sensors at the secondary side <NUM>, before a fault transmission takes place. Additionally, a control pin, independent of the supply <NUM> of the primary side <NUM>, may be used to control the push pull drive of the transformer <NUM> and thereby the activation of the switch driven at the secondary side <NUM>.

In some embodiments, a transformer based isolation barrier for fault reporting to the primary side <NUM> may be implemented. In some embodiments, isolation capacitors may be used similarly to isolation transformers by coupling through the isolation capacitor's pulsed signals (e.g., carriers or modulated carriers). This can be detected/demodulated at the other side of the isolation, or by shorting the capacitor ends at the secondary side. In some embodiments, optical isolation barriers may be used for fault reporting to the primary side <NUM>.

In some embodiments of implementing fault reporting from the secondary side <NUM> to the primary side <NUM>, time multiplexing with the energy transfer from the primary side <NUM> to the secondary side <NUM> may be implemented. Also in this implementation a buffer capacitor may be utilized as an energy reservoir to keep the secondary side monitoring functions alive while the power transfer from primary to secondary side is interrupted. Time frames that are short enough for a voltage applied to the gate of the driven switch to not fall below a critical level may be implemented, and the energy transfer from the primary side <NUM> to the secondary side <NUM> can be interrupted. During the interruption, time pulses or carriers can be applied to the secondary winding and detected at the primary winding as an indication of a fault that happened at the secondary side <NUM>. In some embodiments, a single isolation barrier (inductive or capacitive) may be used by means of time multiplexing.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions. The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM> used to control a transformer <NUM>, a rectification and gate driver component <NUM> for driving a gate of a controlled switch <NUM>, and protection functions <NUM> provided by a monitoring component. In some embodiments, the controlled switch <NUM> is chip or package integrated, and thus sensing of relevant parameters may be accomplished with functionality that is circuit or package integrated. For example, temperature, voltage, or current monitoring may be performed on chip or in package by means of integrated structures implementing the protection functions <NUM>, instead of relying on external components.

In some embodiments, the controlled switch <NUM> is integrated together with the protection functions <NUM> in a solid state relay arrangement. In some embodiments, an arrangement of <NUM> driven switches is illustrated (e.g., controlled switch <NUM> and controlled switch <NUM>) in order to implement a bidirectional controlled switch. This arrangement is suitable for switching AC signals.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM> used to control a first transformer <NUM>, a rectification and gate driver component <NUM> for driving a gate of a controlled switch <NUM>, a buffer capacitor CBUF <NUM>, protection functions <NUM> provided by a monitoring component, a fault manager <NUM>, and a second transformer <NUM> through which fault detection signals are transmitted from the protection functions <NUM> to the fault manager <NUM> used to output the fault detection signals through a fault output pin <NUM>.

In some embodiments, the apparatus <NUM> is configured according to a solid state relay arrangement that has an integration of the controlled switch <NUM> together with the protection functions <NUM>, fault communication to a primary side, and signaling at the primary side according to the solid state relay arrangement. The first transformer <NUM> is used for power transfer from the primary side to the secondary side while a second transformer <NUM> is used for fault signal transfer from the secondary side to the primary side.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM> used to control a transformer <NUM>, a rectification and gate driver component <NUM> for driving a gate of a first controlled switch <NUM>, a buffer capacitor CBUF <NUM>, protection functions <NUM> provided by a monitoring component, a fault manager <NUM>, and a fault output pin <NUM>.

In some embodiments, the apparatus <NUM> is configured according a solid state relay arrangement that has a controlled bidirectional power switch (e.g., the first controlled switch <NUM> and a second controlled switch <NUM>) together with the protection functions <NUM>, fault communication to the primary side, and signaling at the primary side according to the solid state relay arrangement. A single transformer <NUM> is used for power transfer from the primary side to the secondary side. The single transform is also used for fault signaling by shorting a transformer secondary winding and detecting a current consumption increase at the primary side as a signal that a fault occurred.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. The apparatus <NUM> comprises a voltage supply <NUM>, CT driver and logic <NUM>, a transformer <NUM>, a rectification and gate driver component <NUM> for driving a gate of a controlled switch <NUM>, a buffer capacitors <NUM>, protection functions <NUM> provided by a monitoring component, a fault manager <NUM>, a fault output pin <NUM>, and a capacitive isolation barrier <NUM>.

In some embodiments, the apparatus <NUM> is configured according a solid state relay arrangement that has an integration of the controlled switch <NUM> together with the protection functions <NUM>, fault communication to the primary side, and signaling at the primary side accordingly to a solid state relay arrangement. The transformer <NUM> is used for power transfer from the primary side to the secondary side while the capacitive isolation barrier <NUM> is used for fault signal transfer from the secondary side to the primary side. In some embodiments, isolation capacitors may be used similarly to isolation transformers by coupling the isolation capacitors through pulsed signals (e.g., carriers or modulated carriers), which can be detected/demodulated at the other side of the isolation.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, protection functions, and/or fault communication to a primary side across an isolation barrier. The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM>, a transformer <NUM>, a rectification component <NUM>, protection functions <NUM> provided by a monitoring component, a fault manager <NUM>, a primary side fault output pin <NUM>, a secondary side fault output pin <NUM>, inputs <NUM> for the protection functions <NUM>, and a buffer capacitor CBUF <NUM>.

In some embodiments, the apparatus <NUM> is configuration with of an isolated safety monitor. A single transformer <NUM> is used for power transfer from a primary side to a secondary side. Shorting a transformer secondary winding and detecting a current consumption increase at the primary side as a signal that a fault occurred. In some embodiments, a second transformer, not illustrated, may be implemented for fault signal transfers.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, indirect gate drive, and/or protection functions. In some embodiments, the apparatus <NUM> is configured with an integration of an isolated gate driver with an isolated transformer based power converter <NUM>. This provides an output-to-input voltage conversion ratio larger than <NUM> so that the voltage generated for supplying the secondary side is higher than the voltage at the primary side. In some embodiments, the apparatus <NUM> may be configured with a flyback converter, a single phase flyback converter, a flyback converter with <NUM> interleaved phases, a resonant converter (e.g., LLC, LCC, etc.), etc. With power transfer to a secondary domain of the apparatus <NUM> (the secondary side) and a sufficient power conversion efficiency, the generated secondary power supply can be used to supply an isolated gate driver and its related ancillary functions such as ancillary protection functions.

The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM>, a first transformer <NUM>, a power converter <NUM>, gate driver logic <NUM> of an isolated gate driver, a secondary transformer <NUM>, input logic <NUM>, a buffer capacitor CBUF <NUM>, and/or other components. In some embodiments, the apparatus <NUM> is configured with an integration of a transformer based isolated power converter together with an isolated gate driver associated with the isolated gate driver logica <NUM>. The power converter topology is configured such that a voltage difference VDD2-VGND2 is substantially larger than VDD1-VGND1. The integrated power converter and the arrangement with isolated gate driver may utilize an external energy tank or filter, represented by the buffer capacitor CBUF <NUM>. The second transformer <NUM> is part of the isolated gate driver associated with isolated gate driver logic <NUM>. In some embodiments, the second transformer <NUM> may be exchanged with a capacitive or optical isolation barrier. In some embodiments, the apparatus <NUM> comprises dedicated pins for gate driver ancillary functions.

In some embodiments, the isolated gate driver may also offer fault signaling at the primary side. This can be achieved by adding an isolation barrier (transformer, capacitive, or optical based) to carry out the fault communication from the secondary side to the primary side. Alternatively, a single galvanic isolation barrier may be used in the isolated gate driver implementation, which supports bidirectional communication (e.g. through time multiplexed primary or secondary transformer winding drive) for gate drive control signals from the primary side to the secondary side and for fault reporting signals from the secondary side to the primary side. This is generally beneficial in terms of integrated silicon die area, which is illustrated in <FIG>.

<FIG> illustrates an embodiment of an apparatus <NUM> for providing power transfer, direct gate drive, protection functions, and/or fault communication to a primary side across an isolation barrier. In some embodiments, the apparatus <NUM> is configured with an integration of an isolated gate driver with an isolated transformer based power converter <NUM>, which provides an output-to-input voltage conversion ratio larger than <NUM> so that the voltage generated to supply the secondary side is higher than the voltage at the primary side. The apparatus <NUM> comprises a voltage supply <NUM>, transformer driver and logic <NUM>, a first transformer <NUM>, a power converter <NUM>, gate driver logic and safety functions <NUM>, a second transformer <NUM>, input logic <NUM>, a buffer capacitor CBUF <NUM>, a fault output pin <NUM>, and/or other components.

In some embodiments, the apparatus <NUM> is configured with an integration of a transformer based isolated power converter together with an isolated gate driver associated with the isolated gate driver logic and safety functions <NUM>. The power converter topology is configured such that the voltage difference VDD2-VGND2 is substantially larger than VDD1-VGND1. The second transformer <NUM> is part of an isolated gate driver associated with isolated gate driver logic and safety functions <NUM>. In this case, a single galvanic isolation barrier is used for bidirectional communication in the isolated gate driver. In some embodiments, the apparatus <NUM> comprises dedicated pins for gate driver ancillary functions. The isolated gate driver logic and safety functions <NUM> may implement a safety monitoring and/or related countermeasures feature. In some embodiments, the apparatus <NUM> may implement a reporting feature and/or an integrated power driven switch feature, which may be implemented with the integration of single or bidirectional electronic switches.

As used in this application, the terms "component," "module," "system", "interface", and the like are generally intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. One or more components may be localized on one computer and/or distributed between two or more computers.

Furthermore, the claimed subject matter may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a computer to implement the disclosed subject matter. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media.

Various operations of embodiments are provided herein. In one embodiment, one or more of the operations described may constitute computer readable instructions stored on one or more computer readable media, which if executed by a computing device, will cause the computing device to perform the operations described. The order in which some or all of the operations are described should not be construed as to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated by one skilled in the art having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein.

Any aspect or design described herein as an "example" is not necessarily to be construed as advantageous over other aspects or designs. Rather, use of the word "example" is intended to present one possible aspect and/or implementation that may pertain to the techniques presented herein. Such examples are not necessary for such techniques or intended to be limiting. Various embodiments of such techniques may include such an example, alone or in combination with other features, and/or may vary and/or omit the illustrated example.

As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. In addition, the articles "a" and "an" as used in this application and the appended claims may generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Also, unless specified otherwise, "first," "second," or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B or two different or two identical elements or the same element.

Claim 1:
An apparatus, comprising:
an energy transfer device (<NUM>) configured to supply power from a primary side (<NUM>) of an isolation barrier (<NUM>) through the isolation barrier (<NUM>) to a secondary side (<NUM>) of the of the isolation barrier (<NUM>) to directly drive a gate of a switch (<NUM>) for controlling output of the switch (<NUM>) at the secondary side (<NUM>), wherein the gate of the switch (<NUM>) is driven directly by the power supplied from the primary side (<NUM>) and without a gate driver inbetween;
a pulldown device (<NUM>) configured to passively deactivate the switch (<NUM>) when no power transfer is being performed by the energy transfer device (<NUM>) to drive the gate of the switch (<NUM>);
a charge pump (<NUM>) configured to disable the pulldown device (<NUM>) from passively deactivating the switch (<NUM>) when the power transfer is being performed, and wherein a load at the charge pump (<NUM>) enables the pulldown device (<NUM>) to passively deactivate the switch (<NUM>) when the power transfer is not being performed; and
a monitoring component (<NUM>) configured to:
monitor an operating state of the switch (<NUM>);
evaluate the operating state to determine whether a fault has occurred; and
in response to the operating state indicating the fault, implement a countermeasure to turn off the switch (<NUM>), and wherein the pulldown device (<NUM>) at the secondary side (<NUM>) is activated to turn off the switch (<NUM>).