Control device and power conversion circuit thereof with reconfigurable power structure

A control device includes a first switch, a second switch, a switching circuit, a first circuit and a second circuit. The control device is selectively switched to a first mode or a second mode corresponding to an operating current and an operating state of a predetermined circuit. During the first mode, an output signal of the first circuit is transmitted to a control end of the first switch through the switching circuit, and the first circuit and the first switch form a low drop-out regulator. During the second mode, a plurality of driving signals of the second circuit are transmitted to the control end of the first switch and a control end of the second switch through the switching circuit, and the first switch, the second switch and an impedance circuit form a switching voltage converter.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 106124234, filed on Jul. 20, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure is related to a control device and a power conversion circuit thereof and especially is related to a reconfigurable power structure and the power conversion circuit thereof.

Related Art

Corresponding to systematic integration, most of microcontrollers may have built-in low dropout regulators. Besides, as operating voltage of core logic in the microcontroller is reduced, the microcontroller further includes a switching voltage converter. However, when the microcontroller enters sleep status or low power consumption status, the operating current of the microcontroller may be only several micro amperes (μA) or be lower than micro ampere. Therefore, in sleep status or low power consumption status, if microcontroller supplies power by continuously using the switching voltage converter, power consumption will be increased. Besides, in recent years, the application of microcontrollers integrated with radio frequency circuit has increased. However, when microcontroller operates the radio frequency circuit, power source noise introduced by the switching voltage converter often interferes the radio frequency circuit.

SUMMARY

The invention provides a control device and a power conversion circuit thereof, and the control device may supply power by selectively using a low dropout regulator or a switching voltage converter, so as to useful to reduce consumption of power and the interference of noise of the power source.

The invention provides a control device including a first switch, a second switch, a switching circuit, a first circuit, and a second circuit. The first switch and the second switch are connected between a power voltage and a ground terminal in series, and a first node electrically is connected to an impedance circuit through a first pin of the control device. The first node is disposed between the first switch and the second switch. The switching circuit is electrically connected to the first switch and the second switch. The first circuit is electrically connected to the switching circuit. The first circuit and the first switch are configured to form a low dropout regulator when an operating current of the control device is smaller than a current threshold value. An output signal of the first circuit is transmitted to a control terminal of the first switch through the switching circuit, and a low dropout regulator is formed by the first circuit and the first switch. The second circuit is electrically connected to the switching circuit. The first switch, the second switch and the impedance circuit are configured to form a switching voltage converter when the operating current of the control device is not smaller than the current threshold value, a plurality of driving signals of the second circuit are transmitted to the control terminal of the first switch and the control terminal of the second switch through the switching circuit respectively, and a switching voltage converter is formed by the first switch, the second switch and the impedance circuit.

The invention provides a control device including a first switch, a second switch, a switching circuit, a first circuit, and a second circuit. The first switch and the second switch is connected between a power voltage and a ground terminal in series, and a first node electrically connected to an impedance circuit through a first pin of the control device. The first node is disposed between the first switch and the second switch. The switching circuit is electrically connected to the first switch and the second switch. The first circuit and the second circuit are electrically connected to the switching circuit respectively. When the control device operates a pre-determined circuit, the control device switches to a first mode, and when the control device stops operates the pre-determined circuit, the control device switches to the first mode or a second mode according to an operating current. In the first mode, an output signal of the first circuit is transmitted to a control terminal of the first switch through the switching circuit, and the first circuit and the first switch are configured to form a low dropout regulator. In the second mode, a plurality of driving signals of the second circuit are transmitted to the control terminal of the first switch and a control terminal of the second switch through the switching circuit respectively, and the first switch, the second switch and the impedance circuit are configured to form a switching voltage converter.

The invention provides a control device including a first switch, a second switch, a third switch, a first circuit, a second circuit and a switching circuit. The first switch and the second switch are connected between a power voltage and a ground terminal in series, and a first node is electrically connected to a first terminal of an impedance circuit through a first pin of the control device. The first node is disposed between the first switch and the second switch. The third switch has a first terminal electrically connected to the first node, and a second terminal is electrically connected to a second terminal of the impedance circuit through a second pin of the control device. The first circuit and the second circuit are respectively electrically connected to the second pin. In a first mode, the control device conducts the third switch, the switching circuit transmits an output signal of the first circuit to a control terminal of the first switch, and the first circuit and the first switch are configured to form a low dropout regulator. In a second mode, the control device turns off the third switch, the switching circuit transmits a plurality of driving signals of the second circuit to the control terminal of the first switch and a control terminal of the second switch respectively, and the first switch, the second switch and the impedance circuit are configured to form a switching voltage converter.

The invention provides a power conversion circuit including a first switch, a second switch, an amplifier, and a switching circuit. The first switch and the second switch are connected between a power voltage and a ground terminal in series, and a first node is electrically connected to a first terminal of an impedance circuit. The first node is disposed between the first switch and the second switch. The amplifier is electrically connected to a second terminal of the impedance circuit through a voltage divider. The switching circuit is electrically connected to the first switch, the second switch and the amplifier. In a first mode, the power conversion circuit turns off the second switch, the switching circuit conducts an output terminal of the amplifier to a control terminal of the first switch, and the amplifier, the voltage divider and the first switch are configured to form a low dropout regulator. In a second mode, the power conversion circuit disables the amplifier, the switching circuit transmits a plurality of driving signals to a control terminal of the first switch and a control terminal of the second switch respectively, and the first switch, the second switch and the impedance circuit are configured to form a switching voltage converter.

Based on the above, the control device and its power conversion circuit may supply power selectively by using the low dropout regulator or the switching voltage converter, so that it may help to decrease power consumption and interference of power source noise. Besides, due to the switching voltage converter and the low dropout regulator share the first switch, so that production cost and hardware space can be decreased effectively.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1is a schematic diagram of a control device according to an embodiment of the invention. As shown inFIG. 1, a control device100including a first pin PN11and a second pin PN12, and the control device100may be electrically connected to an impedance circuit101through the first pin PN11and the second pin PN12. The impedance circuit101is set outside of the control device100. Besides, the control device100includes a power conversion circuit110and a controller120. The power conversion circuit110is configured to supply power source which the controller120requiring. For instance, the controller120may be operated under a first operating voltage VDD1or second operating voltage VDD2generated by a power conversion circuit110.

The power conversion circuit110includes a first switch111, a second switch112, a switching circuit113, a first circuit114and a second circuit115. The first switch111and the second switch112connect in series between power voltage VSS and ground terminal. A first node ND11is electrically connected to first terminal of the impedance circuit101through the first pin PN11. The first node ND11is disposed between the first switch111and the second switch112. The switching circuit113is electrically connected to the first switch111, the second switch112, the first circuit114and the second circuit115. Besides, the first circuit114and the second circuit115are electrically connected to second terminal of the impedance circuit101. The first switch111may be a P-type Power PMOSFET, the second switch112may be an N-type power MOSFET, but not limited thereto.

In more detail, the switching circuit113includes a first transmission gate141, a second transmission gate142and an AND gate143. The first circuit114includes a first resistor151, a second resistor152and an amplifier153. An input terminal of the first transmission gate141is electrically connected to an output terminal of the amplifier153, and an output terminal of the first transmission gate141is electrically connected to the control terminal of the first switch111. An input terminal of the second transmission gate142is electrically connected to the second circuit115, and an output terminal of the second transmission gate142is electrically connected to a control terminal of the first switch111. Besides, the first transmission gate141and the second transmission gate142are controlled by control signal CT and inversion signal CTB of the control signal CT. The second circuit115may be a buck driving circuit, but not limited thereto.

A first input terminal of the AND gate143is electrically connected to the second circuit115, a second input terminal of the AND gate143receives the inversion signal CTB, and the output terminal of AND gate143is electrically connected to the control terminal of the second switch112. The first resistor151and the second resistor152are connected in series between the second pin PN12and the ground terminal to form a voltage divider. A first input terminal of the amplifier153is electrically connected to the second node ND12between the first resistor151and the second resistor152. In other words, the amplifier153may be electrically connected to the second terminal of the impedance circuit101through the voltage divider. Besides, the second input terminal of the amplifier153receives first reference voltage VR11, an output terminal of the amplifier153is electrically connected to the switching circuit113, and an enable terminal of the amplifier153receives control signal CT.

In operation of the control device100, the controller120may use the control signal CT switching the control device100to the first mode or the second mode, and the power conversion circuit110of the control device100may be corresponding to different mode and be formed in different power source structure. For example: a low dropout regulator and a switching voltage converter. The control signal CT generated by the controller120may be converted to the inversion signal CTB through the inverter130.

In particular, the power conversion circuit110may be corresponding to the control signal CT with high level and enter first mode. In the first mode, the controller120may enable the amplifier153by using the control signal CT with high level, and may disable the second circuit115by using the inversion signal CTB with low level. Besides, in the first mode, the first transmission gate141and the second transmission gate142may be corresponding to the control signal CT and the inversion signal CTB to conduct the control terminal of the first switch111to the output terminal of the amplifier153. The AND gate143may output low level signal corresponding to the inversion signal CTB of low level, so as to turns off the second switch112. At this time, the switching circuit113may transmit output signal of the amplifier153of the first circuit114to the control terminal of the first switch111, and the first circuit114and the first switch111may be configured to form the low dropout regulator. Thereby, the control device100may use the low dropout regulator to make the power voltage VSS regulated to the first operating voltage VDD1, so that the controller120can be operated lower than the first operating voltage VDD1.

On the other hand, the power conversion circuit110may enter the second mode corresponding to the control signal CT with low level. In the second mode, the controller120may use control signal CT with low level to disable the amplifier153, and may use the inversion signal CTB with high level to enable the second circuit115, so as to enable the second circuit115may generate a plurality of driving signal DR11˜DR12.

Besides, in the second mode, the first transmission gate141and the second transmission gate142may be corresponding to the control signal CT and the inversion signal CTB to conduct the control terminal of the first switch111to the second circuit115, so as to transmit the driving signal DR11to the control terminal of the first switch111. The AND gate143may be corresponding to the inversion signal CTB with high level transmits the driving signal DR12to the control terminal of the second switch112. At this time, the first switch111, the second switch112and the impedance circuit101may be configured to form a switching voltage converter, and the switching voltage converter is controlled by the driving signals DR11˜DR12generated from the second circuit115.

Thereby, the control device100may convert the power voltage VSS to the second operating voltage VDD2by using the switching voltage converter, so as to cause the controller120may be operated at the second operating voltage VDD2. Besides, the second circuit115may adjust the driving signals DR11˜DR12according to second reference voltage VR12and the second operating voltage VDD2. Moreover, the impedance circuit101may include an inductor102and a capacitive103, such that a switching voltage converter of buck may be formed by the first switch111, the second switch112and the impedance circuit101.

In other words, in overall operation of the control device100, the controller120may enable one of the first circuit114and the second circuit115by using the control signal CT and the inversion signal CTB. Besides, the controller120may control the switching circuit113by using the control signal CT and the inversion signal CTB. For example, the first transmission gate141and the second transmission gate142in the switching circuit113may conduct the control terminal of the first switch111to the output terminal of the amplifier153or the second circuit115. Thereby, the power conversion circuit110may form different power source structures, for example: the low dropout regulator and the switching voltage converter. Besides, due to the switching voltage converter and the low dropout regulator formed by the power conversion circuit110share the first switch111, so that the production cost and the hardware space can decrease effectively.

In one embodiment, the control device100may reconstruct power source structure of the power conversion circuit110according to the operating current of the controller120, so as to help to reduce power consumption. For instance, the controller120may compare operating current and current threshold value to each other, and switch level of the control signal CT according to comparison result, so that the control device100may switch to the first mode or the second mode in response to the control signal CT.

Particularly, when the operating current of the controller120is smaller than the current threshold value, the controller120is situated in light load status (for example, sleep status or low power consumption status). At this time, the controller120may switch the power conversion circuit110into the first mode, so that (the controller120) use the low dropout regulator formed by the power conversion circuit110to perform power. On the other hand, when the operating current of the controller120is not shorter than the current threshold value, it indicates that the controller120is in heavy load status. At this time, the controller120may switch the power conversion circuit110into the second mode, so that (the controller120) uses the switching voltage converter formed by the power conversion circuit110to provide power.

It is worth to note that,FIG. 2is the figure of the power conversion efficiency of the low dropout regulator and the switching voltage converter in different output current. A curve210is power conversion efficiency curve of the low dropout regulator, and a curve220is power conversion efficiency curve of the switching voltage converter. As shown inFIG. 2, the low dropout regulator has better power conversion efficiency at light load, and the switching voltage converter has better power conversion efficiency at heavy load. In other words, the control device100may be corresponding to the load status of the controller120to select the power source structure having better power conversion efficiency to supply power to the controller120. Therefore, the power consumption can be effectively reduced.

Additionally, the low dropout regulator has excellent power supply rejection ratio (PSRR), so that the first operating voltage VDD1having lower noise may be provide. Therefore, in another embodiment, the control device100may further supply power to the pre-determined circuit sensitive with noise by using the low dropout regulator, so that it may reduce the interference from the pre-determined circuit.

Particularly, in another embodiment, the controller120includes a pre-determined circuit121sensitive to the noise, for example: analog-to-digital converter or radio frequency circuit. Before the controller120compares the operating current and the current threshold value, the controller120may determine priory whether the pre-determined circuit121inside is activated or enabled. When the pre-determined circuit121of the controller120is enabled (i.e. when the controller120operates the pre-determined circuit121), the controller120may switch the power conversion circuit110to the first mode, in order to use the low dropout regulator formed by power conversion circuit110to supply power. Thereby, the interference of the power source noise to the pre-determined circuit121is decreased. On the other hand, when the pre-determined circuit121in the controller120is disabled (i.e., when the controller120stops operating the pre-determined circuit121), the control device100may switch to the first mode or the second mode selectivity according to the operating current, so that it is helpful to decrease power consumption.

FIG. 3is a schematic diagram of a control device according to another embodiment of the invention. Compared with the embodiment ofFIG. 1, the control device300ofFIG. 3further comprises a third switch310. A first terminal of the third switch310is electrically connected to the first node ND11, and the second terminal of the third switch310is electrically connected to the second terminal of the impedance circuit101through the second pin PN12of the control device300. The third switch310may be an N-type Power PMOSFET.

In operation, when the control device300is switched to the first mode, the control device300conducts the third switch310, and the first circuit114and the first switch111may be configured to form the low dropout regulator. At this point, the third switch310which is conducted may made two ends of the inductor102in the impedance circuit101short circuit, so as to make the current from the first switch111may transmit to the first circuit114through the third switch310, not flowing through the inductor102. Thereby, the effect of the inductor102to the low dropout regulator may be prevented, and the interference of the power source noise to the pre-determined circuit121may be further decreased. Besides, when the control device300is switched to the second mode, the control device300turns off the third switch310, and the first switch first switch, the second switch112and the impedance circuit101are configured to form the switching voltage converter.

Similar to the embodiment ofFIG. 1, the controller120may determine whether the pre-determined circuit121in the internal is activated or enable. When the pre-determined circuit121in the controller120is enabled (i.e., when the controller120operates the pre-determined circuit121), the controller120may switch the control device300to the first mode. On the other hand, when the pre-determined circuit121in the controller120is disabled (i.e., when the controller120stops to operate the pre-determined circuit121), the controller120may compare the operating current and the current threshold value, and then switch the control device300to the first mode or the second mode according to the comparison result. The detail configuration and operation in each device ofFIG. 3has included in the embodiment inFIG. 1andFIG. 2, and is not repeated here.

To summarize, the control device of the disclosure may selectivity switch to the first mode or the second mode corresponding to the operating current of the controller and the operational state of the pre-determined circuit in the controller, and the power conversion circuit in the control device may form different power source structure according to different mode, for example: the low dropout regulator and the switching voltage converter. Thereby, power consumption and interference of power noise of the control device and the power conversion circuit thereof may be decreased effectively. Besides, the switching voltage converter and the low dropout regulator formed by the power conversion circuit share the first switch, so that production cost and hardware space may be decreased.