METHODS, APPARATUS, AND SYSTEMS TO FACILITATE CONTROL FOR A LOW-POWER BATTERY STATE

Methods, systems, and apparatus to facilitate control for a low-power battery state are disclosed. An example apparatus includes a charge pump coupled to a power terminal and a charge pump switch, the charge pump switch coupled to a discharging terminal; a power supply switch circuit coupled to the power terminal and the discharging terminal, the power supply switch circuit being connected to bypass the charge pump and the charge pump switch; and a switch controller coupled to the charge pump switch and the power supply switch circuit.

FIELD OF THE DISCLOSURE

This disclosure relates generally to battery control and, more particularly, to methods, apparatus, and systems to facilitate control for a low-power battery state.

BACKGROUND

Battery packs, such as lithium ion battery packs, include a battery and circuitry to charge and/or discharge the battery to/from a load. Some battery packs include one or more transistors to enable the control the charging and/or discharging of the battery. In some examples, the voltage required to control the one or more transistors is above the voltage supplied by the battery. In such examples, a charge pump may be used to turn on (e.g., enable) and keep on the one or more transistors to be able to provide power to a load and/or receive power from a load.

SUMMARY

Certain examples disclosed herein facilitate control for a low-power battery state. An example apparatus includes a charge pump coupled to a power terminal and a charge pump switch, the charge pump switch coupled to a discharging terminal. The example apparatus further includes a power supply switch circuit coupled to the power terminal and the discharging terminal, the power supply switch circuit being connected to bypass the charge pump and the charge pump switch. The example apparatus further includes a switch controller coupled to the charge pump switch and the power supply switch circuit.

Certain examples disclosed herein facilitate control for a low-power battery state. An example apparatus includes a power supply switch circuit to, when enabled, provide a first voltage to a discharging terminal. The example apparatus further includes a charge pump to, when enabled, provide a second voltage higher than the first voltage to the discharging terminal. The example apparatus further includes a controller to enable the power supply switch circuit or the charge pump based on at least one of instructions from a host controller or a current being drawn from a power supply corresponding to the first voltage.

Certain examples disclosed herein facilitate control for a low-power battery state. An example system includes a power supply. The example system further includes a field effect transistor including a drain connected to the power supply and a source connected to a positive terminal. The example system further includes an integrated circuit to when a host device is operating in a low power mode, couple the power supply to a gate of the field effect transistor; and when the host device is operating in a high power mode, couple a charge pump to the gate of the field effect transistor, the charge pump providing a voltage higher than a power supply voltage of the power supply.

DETAILED DESCRIPTION

Portable products rely on power supplies (e.g., batteries) to provide power for operation. For example, a portable device may utilize a lithium ion battery in a battery pack to provide power to the portable device. Some battery packs include series field effect transistor (FET) protection in line with the positive terminal of the battery. Such battery packs include a protector integrated circuit (IC) to control the series FETs for the charging and discharging of the battery(ies). For example, the protector IC may (A) enable a first FET of the series FETs to allow a high voltage from the connected portable device (e.g., a host device) to charge the battery and (B) enable a second FET of the series FETs to allow the battery to discharge, thereby providing power to the connected portable device.

Because a load of a host device may draw a lot of current from a battery, one or more charge pumps may be required to increase the battery voltage to enable the first FET or the second FET of the series FETs in a battery pack. The increased voltage is applied to the gate of the first or second FET to turn on the corresponding FET and keep it on. Such charge pumps consume substantial current (e.g., 50 microamps per pump). Accordingly, utilizing the charge pump to discharge the battery depletes the battery rather quickly. For high current/high-power modes (e.g., where the load of the portable device is high), a charge pump is necessary to adequately turn on the FET.

Some portable devices do not always operate in high-power modes. For example, if the portable device is a power tool, the power tool may operate in high-power mode/high-current mode and low-power/low-current mode during different time periods. In such an example, when the power tool is utilized, the power tool may draw a large amount of current from a battery (e.g., high-power mode); however, when the power tool is being stored, the power tool may have a microcontroller to perform small tasks and/or checks. Additionally or alternatively, a user may interact with a user interface of the power tool to check data related to the power tool. Operations of the interface and/or microcontroller may draw very small amounts of current (e.g., corresponding to low power mode) from the battery. For low current/power mode (e.g., where the load of the portable device is low), the voltage at the gate of the discharging FET does not need to be as high as it does in high-power modes. Accordingly, utilizing a charge pump to enable the battery to charge the power tool in low-power mode is a waste of resources, thereby corresponding to faster battery depletion.

Examples disclosed herein provide operation of a discharging FET in a battery pack in two modes (e.g., a low-power mode and a high-power mode). The high-power mode utilizes the charge pump to provide sufficient voltage to enable the discharging FET in high power modes. The low-power mode enables discharging through the FET without the use of the charge pump (e.g., by bypassing the charge pump). Rather, the low-power mode utilizes the voltage of the battery to enable the discharging FET. In this manner, due to not utilizing the charge pumps, the amount of power wasted to provide power in low power modes is significantly reduced, thereby extending the life of the battery.

FIG. 1illustrates an example power supply pack100including an example power supply102and an example power supply controller104to facilitate control for a lower power state during a discharging state. The power supply pack100ofFIG. 1includes the power supply102, the power supply controller104, example metal oxide semiconductor FETs (MOSFETs)106,108, example body diodes107,109, an example resistor110, an example protector integrated circuit (IC)112, an example charge pump circuit114, an example switch116, an example power supply switch circuit118, an example switch controller120, an example resistor123, and an example sensor122(e.g., a current sensor or a voltage sensor, whose voltage corresponds to a current).

FIG. 1further includes an example host device123coupled to the power supply pack100(e.g., via example positive and negative terminals (Pack+ and pack−)). The host device123includes an example power supply regulator124, an example host microcontroller126and an example load128coupled to the power supply pack100.FIG. 1further includes an example power terminal (POWER)130, an example sensor terminal (SENSOR)132, an example charging terminal (CHG)134, an example discharging terminal (DSG)136, an example clock terminal (CLK)138, an example data terminal (DATA)140, an example PACK+ terminal144, and an example PACK− terminal144. The power supply102may be a battery (e.g., a lithium ion battery), an AC power supply, and/or any other type of power supply. The MOSFETs106,108may be n-channel FETs, power FETs, and/or any other type of electronic switch. Additionally, in some examples, the power supply pack100may include a parallel power down path connecting the gate of the MOSFET108to the PACK+ terminal144for faster equalization (not shown).

The protector IC112receives data from the host controller126regarding whether to charge the power supply102or discharge the power supply102(e.g., thereby providing power to the load128in a low-power or high-power mode). As further described below, to charge the power supply102, the protector IC112enables the MOSFET106and enables the MOSFET108. In this manner, the current from the load can be used to charge the power supply102via the MOSFETs106,108. To discharge the power supply102in a low-power mode (e.g., when the current required for the load128is low), the protector IC112disables the MOSFET106and enables the MOSFET108. In this manner, current flows from the power supply102, through the body diode107of the MOSFET106and through the enabled MOSFET108to provide a small current to the load128. To discharge the power supply102in high-power mode (e.g., when the current required for the load126is high), the protector IC112enables both MOSFETs106,108. In this manner, current flows through the enabled MOSFETs106,108to provide a large current to the load128.

The protector IC112ofFIG. 1controls the MOSFETs106,108to charge the power supply102and/or to discharge the power supply102(e.g., to provide power to the power supply regulator124and the load128of the host device123). In the example ofFIG. 1, the MOSFETs106,108are n-channel MOSFETs (e.g., nFETs). The protector IC112enables the example MOSFETS106using a high voltage applied to the CHG terminal134and using a low voltage applied to the DSG terminal136. When the protector IC112applies a high voltage to the gate of the MOSFET106(e.g., a charging switch), the protector IC112enables (e.g., turns on) the MOSFET106to charge the power supply102using a high voltage (e.g., provided by the load128) at the PACK+ terminal144(e.g., via current flowing through the body diode109of the MOSFET108and through the MOSFET106). To discharge the power supply102, the protector IC112applies a high voltage to the gate of the MOSFET108(e.g., a discharging switch) to enable the MOSFET108. In this manner, the current from the power supply102flows through the body diode107of the MOSFET106(e.g., around the MOSFET106) and through the MOSFET108to provide current to the power supply regulator124and the load128. During high-power modes, the protector IC112may utilize the charge pump114provide a voltage to the gate of the MOSFET108that is enough to enable the MOSFET108. The protector IC112may disable the MOSFET108by disabling the charge pump114and/or the power supply switch circuit118, and the resistor110equalizes the gate voltage to turn off (e.g., disable) the MOSFET108.

In low-power modes, the protector IC112ofFIG. 1may couple the gate of the MOSFET108directly to the power supply102via the power supply switch circuit118(e.g., bypassing the charge pump114and switch116). In this manner, the system voltage is maintained by the body diode107of the MOSFET106and the enabled MOSFET108, corresponding to a source follower configuration, which provides sufficient power for the host microcontroller126(e.g., via the power supply regulator124), but not for the full load128. In high-power mode, the system removes the source follower configuration by disabling the power supply switch circuit118and enabling the charge pump circuit114to provide a boost to the gate of the MOSFET108to provide sufficient current to power the load128.

The protector IC112ofFIG. 1includes the charge pump114, the charge pump switch116, the power supply switch circuit118and the switch controller120. The charge pump circuit114generates a voltage higher than the voltage of the power supply102to enable the MOSFET108for high power situations (e.g., where the load128draws a large current from the power supply102). The charge pump circuit114is enabled when the charge pump switch116is closed. The charge pump circuit114requires a large current consumption, corresponding to a lot of power required to turn the MOSFET108on and keep it on (e.g., to supply sufficient current to create a voltage across the resistor110to enable the gate of the MOSFET108). However, in a low power mode, the amount of voltage needed to provide the gate of the MOSFET108is much lower. Accordingly, in low power modes, the power supply switch circuit118may be utilized to drive the gate of the MOSFET108with less voltage than the charge pump114. The protector IC112may include additional components not illustrated inFIG. 1. For example, the protector IC112may include an additional charge pump (not shown) coupled to the POWER terminal130and the charging (CHG) terminal134to enable the charging MOSFET106.

The power supply switch circuit118ofFIG. 1, when enabled, bypasses the charge pump114provides the voltage of the power supply102to enable the gate of the MOSFET108, thereby configuring the MOSFET108as a source follower. For example, when the power supply switch circuit118is enabled, the voltage at the power supply102is shorted to the gate of the MOSFET108and the charge pump114is bypassed (e.g., decoupled via the switch116). Because the voltage at the drain of the MOSFET108is approximately one threshold voltage (e.g., corresponding to the body diode109) below the battery voltage and the voltage at the source of the MOSFET108is approximately the battery voltage minus the threshold voltage minus the gate to source voltage of the MOSFET108(e.g., which is approximately the threshold voltage of the MOSFET108), the battery voltage is sufficient to enable the gate of the MOSFET108. In low-power modes, the voltage at the PACK+ terminal144is sufficient to provide the host microcontroller126(e.g., via the power supply regulator124) with enough power to operate. Examples of the power supply switch circuit118is further described below in conjunction withFIGS. 2 and 3.

The switch controller120ofFIG. 1determines when to use the charge pump circuit114to control the discharging MOSFET108(e.g., for high current/high-power modes) and when to use the power supply switch circuit118to control the discharging MOSFET108(e.g., for low-current/low-power modes). The switch controller120may select a mode (e.g., high-power or low-power) based on a sensed current measurement or a voltage measurement corresponding to a sensed current measurement from the sensor122via the SENSOR terminal132and a ground terminal (e.g., corresponding to the voltage across the resistor123) and/or based on instructions from the host microcontroller126(e.g., via the DATA terminal140). For example, the resistor121is coupled to a node at the PACK+ terminal144and to ground (e.g., or Vss). In this manner, the switch controller120can determine the current by dividing the voltage across the resistor by the resistance of the resistor121and select a mode based on the sensed current. Additionally or alternatively, the microcontroller126may enter into low-power mode and disable the load128. In such an example, the microcontroller126may inform the switch controller120that low-power mode has been initiated and the load128is disabled. Accordingly, the switch controller120may disable the charge pump114(e.g., by opening the switch116) and enable the power supply switch circuit118, thereby reducing power consumption. In this manner, the microcontroller126may still operate without the burden of the large amount of current drawn by the charge pump114. When the microcontroller126is to enter in high-power mode (e.g., requiring high current), the microcontroller126may inform the switch controller120. In this manner, the switch controller120may disable the power supply switch circuit118and enable the charge pump114(e.g., by closing the switch116).

However, if the host microcontroller126ofFIG. 1faults and/or if there is no data connection between the host microcontroller126and the switch controller120, the switch controller120may utilize current measurements from the sensor122to determine which mode to utilize. For example, if the sensor122measures a current (e.g., a voltage across the resistor121that is divided by the resistance of the resistor121to correspond to a current) above a maximum low current threshold, the switch controller120may adjust from power supply switch circuit control to charge pump control (e.g., to provide sufficient power without wearing out the components of the power supply controller104). If the sensor122measures a current below the maximum low current threshold, the switch controller120may adjust from charge pump control to power supply switch circuit control (e.g., to conserve power). The switch controller120is further described below in conjunction withFIG. 5.

FIG. 2is a circuit implementation of an example power supply switch circuit118that may be used for low-power battery states. The power supply switch circuit118includes an example MOSFET200(e.g., an n-channel FET (nFET)), an example resistor202, and example MOSFETs204,206(e.g., a p-channel FETS (pFETs)). The MOSFETs200,204,206may be power FETs and/or any other type of electronic switch.

The MOSFET200ofFIG. 2is a n-channel MOSFET that is controlled by a voltage applied by the switch controller120ofFIG. 1. When the switch controller120applies a low voltage to the gate of the MOSFET200, the MOSFET200disables (e.g., turns off). When the MOSFET200is off, the resistor202equalizes the gate of the MOSFETs204,206to the body of the MOSFETs204,206, thereby disabling the MOSFETs204,206. Because each of the MOSFETs204,206have example body diodes205,207in opposite directions, when the MOSFETs204are disabled, current cannot flow from the battery (POWER) terminal130to the discharging (DSG) terminal136or vice versa, thereby disabling the MOSFET108ofFIG. 1.

When the switch controller120applies a high voltage to the gate of the MOSFET200ofFIG. 2, the MOSFET200enables (e.g., turns on). When the MOSFET200is on, the MOSFET200provides a path to ground, thereby allowing current to flow through the resistor202to provide a gate-to-source voltage (Vgs) drop across the MOSFETs204,206. Thus, the MOSFETs204,206turn on and the POWER terminal130is shorted to the DSG terminal136. In this manner, the voltage from the power supply102is provided to the gate of the MOSFET108ofFIG. 1to enable the MOSFET108.

FIG. 3is an alternative circuit implementation of an example power supply switch circuit300that may be used for low-power battery states. The alternative example power supply switch circuit300includes an example MOSFET301(E.g., an n-channel MOSFET), an example resistor302,304, and example MOSFETs306,308(e.g., a p-channel MOSFET). The MOSFETs301,306,308may be power FETs and/or any other type of electronic switch.

The MOSFET301ofFIG. 3is a n-channel MOSFET controlled by a voltage applied by the switch controller120ofFIG. 1. However, because the MOSFET306includes an example body diode307, when the MOSFET301is disabled, current cannot flow from the DSG terminal136to the POWER terminal130, whenever the voltage at PACK+ is above is above the voltage at BAT, regardless of the state (e.g., on or off) of the MOSFET301.

When the switch controller120applies a high voltage to the gate of the MOSFET301ofFIG. 3, the MOSFET301enables (e.g., turns on). When the MOSFET301is on, the MOSFET301provides a path to ground, thereby allowing current to flow through the resistor302to provide a Vgs drop across the MOSFET306. The Vgs drop across the MOSFET306is sufficient to enable the MOSFET306, thereby shorting the POWER terminal130to the source of the MOSFET308. When the voltage at the PACK+ terminal144is less than the voltage at the DSG terminal136, the voltage drop across the resistor304is sufficient to cause the MOSFET308to turn on (e.g., enable), thereby shorting the POWER terminal130to the DSG terminal136to cause the battery voltage to enable the MOSFET108ofFIG. 1. Either of the power supply switch circuit118ofFIG. 2and the switch circuit300ofFIG. 3may be implemented in the protector IC112ofFIG. 1, each corresponding to certain advantages and disadvantages. A user and/or manufacture may select one of the power supply switch circuits118,300based on their preferences.

FIG. 4illustrates an example battery pack400to facilitate control for a low-power battery state. The battery pack400ofFIG. 4includes the power supply102, the MOSFETs106,108, the resistor110, the charge pump circuit114, the switch116, the switch controller120, and the sensor122ofFIG. 1. The battery pack400further includes an alternative example protector IC402, an example MOSFET404(e.g., an n-channel MOSFET), example resistors406,410,412, and an example MOSFET408(e.g., a p-channel MOSFET). The alternative protector IC402may include additional components not illustrated inFIG. 4. For example, the protector IC402may include an additional charge pump (not shown) coupled to the POWER terminal130and the charging (CHG) terminal134to enable the charging MOSFET106. The MOSFETs404,408,410may be power FETs and/or any other type of electronic switch.

The protector IC402ofFIG. 4includes the charge pump114the switch116, and the switch controller120ofFIG. 1. However, the protector IC402ofFIG. 1does not drive the gate of the MOSFET108using the power supply switch circuit118ofFIG. 1. Instead, when the switch controller120determines that low-power mode should be initiated, the switch controller120outputs a high voltage to the MOSFET404(e.g., instead of the power supply switch circuit118), thereby enabling the MOSFET404. When the MOSFET404is enabled, current will be drawn from the power supply102through the resistor410and the resistor406, thereby generating a Vgs voltage drop sufficient to turn on (e.g., enable) the MOSFET408. The resistance of the resistors406,410may be high to ensure that the current is low for the low-power mode. When the MOSFET408is enabled, current flows from the source to the drain of the MOSFET408, which is limited by the resistor412. Using the MOSFET408, there is no need to generate a voltage that is higher than the voltage of the power supply102. Accordingly, the voltage of the power supply102can be provided to the PACK+ terminal144without the use of the charge pump114for low-power mode by enabling the MOSFET408(e.g., when the switch controller120enabled the MOSFET404). Although the example circuit ofFIG. 4may require additional components, the example circuit ofFIG. 4may be implemented on an existing protector IC402that does not support the power supply switch circuit118ofFIG. 1.

FIG. 5is a block diagram of the switch controller120ofFIGS. 1 and 4. The switch controller120includes an example interface500, an example mode determiner502, and an example switch driver504.

The interface500ofFIG. 5interfaces with the sensor122and/or the host microcontroller126(e.g., via the DATA terminal140). In some examples, the interface500includes two interfaces (e.g., one for the sensor122and one for the host microcontroller126). The sensor122provides current measurements (e.g., the amount of current being drawn from the power supply102) to the interface500. In some examples, the sensor122provides a voltage measurement and mode determiner502calculates the current by dividing the voltage measurement by the resistance of the resistor121. The host microcontroller126provides instructions corresponding to a power mode (e.g., high-power or low-power). For example, if the host microcontroller126determines that the load128requires a large amount of current and/or is connected, the host microcontroller126may transmit instructions corresponding to the high-power mode to the interface500. If the microcontroller126determines that the load128requires a small amount, or no, current and/or is disconnected, the host microcontroller126may transmit instructions corresponding to the low-power mode to the interface500.

The mode determiner502ofFIG. 5makes a determination as to which mode to operate under (e.g., high-power mode or low-power mode) based on the received information from the sensor122and/or the host microcontroller126. For example, if the host microcontroller126transmits instructions corresponding to a low-power mode, the mode determiner502selects the low-power mode. As described above, the low-power mode corresponds to disabling the charge pump114ofFIGS. 1 and 4and enabling the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4. If the host microcontroller126transmits instructions corresponding to a high-power mode, the mode determiner502selects the high-power mode. As described above, the high-power mode corresponds to enabling the charge pump114ofFIGS. 1 and 4and disabling the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4.

Additionally or alternatively, the mode determiner502ofFIG. 5may determine a mode and/or change modes based on a received current measurement from the sensor122(e.g., or a voltage corresponding to the current measurement). For example, the mode determiner502may compare the received current measurement to a maximum low current threshold. If the received current measurement is above the maximum low current threshold, the mode determiner502may utilize high-power mode and when the received current measurement is below the maximum low current threshold, the mode determiner502may utilize the low-power mode. In some example, the mode determiner502may override the mode corresponding to the instructions from the host microcontroller126based on the current measurement. For example, if the instructions from the host microcontroller126corresponds to a low-power mode and the current from the sensor122is above the maximum low current threshold, the mode determiner502may override the low-power instructions and select high-power mode to protect the components of the battery packs100,400.

The switch driver504ofFIG. 5drives the power supply switch circuit118ofFIG. 1, the MOSFET404ofFIG. 4, and/or the charge pump114ofFIGS. 1 and 4by applying one or more voltages based on the selected mode. For example, if the mode determiner502selects a low-power mode, the switch driver504applies a first voltage (e.g., a high voltage) to the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4and applies a second voltage (e.g., the low voltage) to the charge pump switch116. In this manner, the switch driver504enables low-power mode by enabling the power supply switch circuit118or the MOSFET404and disabling the charge pump114. If the mode determiner502selects a high-power mode, the switch driver504applies the second voltage (e.g., a low voltage) to the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4and applies the first voltage (e.g., the high voltage) to the charge pump switch116. In this manner, the switch driver504enables high-power mode by disabling the power supply switch circuit118or the MOSFET404and enabling the charge pump114.

While an example manner of implementing the switch controller120ofFIGS. 1 and 4is illustrated inFIG. 5, one or more of the elements, processes and/or devices illustrated inFIG. 5may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the interface500, the mode determiner502, the switch driver504, and/or, more generally, the switch controller120ofFIG. 5may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, the interface500, the mode determiner502, the switch driver504, and/or, more generally, the switch controller120ofFIG. 5could be implemented by one or more analog or digital circuit(s), logic circuits, programmable processor(s), programmable controller(s), graphics processing unit(s) (GPU(s)), digital signal processor(s) (DSP(s)), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and/or field programmable logic device(s) (FPLD(s)). When reading any of the apparatus or system claims of this patent to cover a purely software and/or firmware implementation, the interface500, the mode determiner502, the switch driver504, and/or, more generally, the switch controller120ofFIG. 5is/are hereby expressly defined to include a non-transitory computer readable storage device or storage disk such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc. including the software and/or firmware. Further still, the switch controller120ofFIG. 5may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated inFIG. 5, and/or may include more than one of any or all of the illustrated elements, processes and devices. As used herein, the phrase “in communication,” including variations thereof, encompasses direct communication and/or indirect communication through one or more intermediary components, and does not require direct physical (e.g., wired) communication and/or constant communication, but rather additionally includes selective communication at periodic intervals, scheduled intervals, aperiodic intervals, and/or one-time events.

“Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, and (6) B with C.

FIG. 6is an example flowchart600representative of example machine readable instructions that may be executed by the switch controller120ofFIG. 1to facilitate control for a low-power battery state. Although the example flowchart600ofFIG. 6is described in conjunction with the switch controller120in the battery packs100,400ofFIGS. 1 and/or 4, the flowchart600may be described in conjunction with any switch controller in any type of battery pack.

At block602, the interface500determines if instructions have been received from the host microcontroller126. As described above, the host microcontroller126may transmit instructions corresponding to a low-power mode or a high-power mode. However, if no instructions are received, the switch controller120may use current and/or voltage from the sensor122to determine which mode to use. If the interface500determines that instructions have been received (block602: YES), the process continues to block608, as further described below. If the interface500determines that the instructions have not been received (block602: NO), the interface500receives a current measurement or a voltage measurement corresponding to a current from the sensor122(block604). As described above, the sensor122measures the current being drawn from the power supply102.

At block606, the mode determiner502determines if the received current measurement is below a threshold (e.g., the maximum low-power threshold). If the mode determiner502determines that the received current measurement is below the threshold (block606: YES), the switch driver504enables low-power control (block610). As described above in conjunction withFIG. 5, the switch driver504enables low-power control by applying a first voltage (e.g., a high voltage) to the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4and applying a second voltage (e.g., a low voltage) to the charge pump switch116. In this manner, the switch driver504enables low-power mode by enabling the power supply switch circuit118or the MOSFET404and disabling the charge pump114.

If the mode determiner502determines that the received current measurement is not below the threshold (block606: NO), the switch driver504enables high-power control (block612). As described above in conjunction withFIG. 5, the switch driver504enables high-power control by applying the second voltage (e.g., the low voltage) to the power supply switch circuit118ofFIG. 1or the MOSFET404ofFIG. 4and applying the first voltage (e.g., the high voltage) to the charge pump switch116. In this manner, the switch driver504enables high-power mode by disabling the power supply switch circuit118or the MOSFET404and enabling the charge pump114.

At block608, the mode determiner502determines if the instructions from the host controller126correspond to a low-power mode (or a high-power mode). If the mode determiner502determines that the received instructions corresponds to a low-power mode (block608: YES), the switch driver504enables low-power control (block610), as described above. If the mode determiner502determines that the received instructions do not correspond to a low-power mode (block608: NO) (e.g., the instructions correspond to high-power mode), the switch driver504enables high-power control (block612), as described above.

At block614, the interface500receives a current measurement from the sensor.122Alternatively, the interface500may receive a voltage measurement and the mode determiner502may determine the current by dividing the voltage by the resistance of resistor121. At block616, the mode determiner502determines if the current from the sensor122is contrary to the instructions from the host controller126. For example, if the host controller126transmits instructions corresponding to low-power control, but the current sensed by the sensor122is above the threshold, the mode determiner502may adjust modes to protect the circuiting of the power supply pack100,400. If instructions have not been received, the current will not be contrary to the instructions. If the mode determiner502determines that the current from the sensor122is contrary to the instructions from the host controller126(block616: YES), the process returns to block606to determine how to adjust control. If the mode determiner502determines that the current from the sensor122is not contrary to the instructions from the host controller126(block616: NO), the process returns to block602.

FIG. 7illustrates an example timing diagram700corresponding to node voltages ofFIGS. 1 and/or 4. The timing diagram700includes an example DSG voltage702corresponding to the voltage output by the protector IC112to the gate of the MOSFET108ofFIGS. 1 and/or 4, an example PACK+ voltage704(e.g., a voltage at the DSG terminal136), corresponding to the voltage at the PACK+ terminal114of the battery pack100ofFIGS. 1 and/or 4, and an example power supply voltage704corresponding to the voltage output by the power supply102ofFIGS. 1 and/or 4.

As illustrated inFIG. 7, during a power down mode the power supply voltage704maintains its voltage level. However, because the battery pack100is powered down the protector IC112does not output the DSG voltage702(e.g., the DSG voltage702is at ground or Vss) to the MOSFET108. Thus, the PACK+ voltage704is also at ground (e.g., Vss). During low power mode, the protector IC112utilizes the FET switching circuit118to short the power supply102to the gate of the MOSFET108. In this manner, the DSG voltage702raises to the power supply voltage706. Additionally, during low power mode, the PACK+ voltage704is slightly below the power supply voltage704(e.g., because of the voltage drops across the body diode107). During the high power mode, the protector IC112disables the FET switching circuit118and enabled the charge pump114to increase the DSG voltage702to provide enough voltage to enable the MOSFET108, thereby allowing the PACK+ voltage704to increase to the power supply voltage704(e.g., because both MOSFETS106,108are enabled, the power supply102is shorted to the PACK+ terminal144).

FIG. 8is a block diagram of an example processor platform800structured to execute the instructions ofFIG. 6to implement switch controller120ofFIGS. 1, 4, and/or5. The processor platform800can be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a cell phone, a smart phone, a tablet such as an iPad™), a personal digital assistant (PDA), an Internet appliance, a DVD player, a CD player, a digital video recorder, a Blu-ray player, a gaming console, a personal video recorder, a set top box, a headset or other wearable device, or any other type of computing device.

The processor platform800of the illustrated example includes a processor812. The processor812of the illustrated example is hardware. For example, the processor812can be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor based (e.g., silicon based) device. In this example, the processor implements the interface500, the mode determiner502, and/or the switch driver504ofFIG. 5.

The processor platform800of the illustrated example also includes an interface circuit820. The interface circuit820may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), a Bluetooth® interface, a near field communication (NFC) interface, and/or a PCI express interface. In some examples, the interface circuit820implements the interface500ofFIG. 5.

In the illustrated example, one or more input devices822are connected to the interface circuit820. The input device(s)822permit(s) a user to enter data and/or commands into the processor812. The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system.

The processor platform800of the illustrated example also includes one or more mass storage devices828for storing software and/or data. Examples of such mass storage devices828include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, redundant array of independent disks (RAID) systems, and digital versatile disk (DVD) drives.

The machine executable instructions832ofFIG. 6may be stored in the mass storage device828, in the volatile memory814, in the non-volatile memory816, and/or on a removable non-transitory computer readable storage medium such as a CD or DVD.