TWM657846U - Power conversion device - Google Patents

Abstract

A power conversion device is provided. The power conversion device includes a safety capacitor, a power switch, a charge-and-discharge control circuits and control circuits. The charge-and-discharge control circuit includes a bridge switch and a discharge circuit. A first terminal of the bridge switch is coupled to the safety capacitor via a connection node. The discharge circuit is coupled to a second terminal of the bridge switch. The discharge circuit discharges a voltage on the safety capacitor. The control circuit and the discharge circuit are integrated in a first die. The power switch and the bridge switch are integrated in a second die. The voltage withstand capability of the second die is higher than the voltage withstand capability of the first die.

Description

Power conversion device

The present invention relates to a power conversion device, and in particular to a power conversion device with high voltage resistance.

Current power conversion devices can convert AC power into DC power. Generally speaking, the power conversion device has a safety capacitor (such as an X capacitor) and a discharge circuit for discharging the safety capacitor. The control circuit of the power conversion device is integrated (or packaged) in a die that meets the low voltage withstand capability. Under the requirement of high voltage (such as greater than 600 volts), at least one power switch of the power conversion device must be integrated in a die that meets the high voltage withstand capability. The discharge circuit is integrated in another die that meets the high voltage withstand capability. Therefore, the power conversion device includes a total of three dies with different processes.

It should be noted that multiple connection lines are required to connect the dies. Therefore, the more dies there are, the larger the volume of the power conversion device. Under the design requirements of low volume, the power conversion device cannot accommodate three dies. Therefore, under the requirements of high voltage, how to reduce the number of dies or reduce the volume of the power conversion device is one of the research focuses of technicians in this field.

The novel invention provides a power conversion device with high voltage requirement and small size.

In one embodiment of the present invention, the power conversion device includes a safety capacitor, a power switch, a charge and discharge control circuit, and a control circuit. The charge and discharge control circuit includes a bridge switch and a discharge circuit. The first end of the bridge switch is coupled to the safety capacitor via a connection node. The discharge circuit is coupled to the second end of the bridge switch. The discharge circuit discharges the voltage in the safety capacitor. The control circuit and the discharge circuit are integrated in a first die. The power switch and the bridge switch are integrated in a second die. The voltage withstand capability of the second die is higher than the voltage withstand capability of the first die.

In one embodiment of the novel invention, the power switch is implemented by a gallium nitride field effect transistor.

In one embodiment of the novel invention, the bridge switch is implemented by a gallium nitride field effect transistor.

In one embodiment of the present invention, when the discharge circuit discharges the voltage of the safety capacitor, the control circuit turns on the bridge switch.

In one embodiment of the present invention, the charge-discharge control circuit further includes a charging circuit. The charging circuit is coupled to the second end of the bridge switch. The charging circuit charges the voltage at the connection node. The charging circuit is integrated in the first die.

In one embodiment of the present invention, when the charging circuit charges the voltage at the connection node, the control circuit turns on the bridge switch.

In one embodiment of the present invention, the power conversion device further includes a voltage divider circuit. The voltage divider circuit is coupled to the connection node and the control circuit. The voltage divider circuit generates a feedback voltage according to the voltage value at the connection node. The control circuit determines the voltage value of the safety capacitor according to the feedback voltage. The voltage divider circuit is integrated in the second die.

In one embodiment of the present invention, the power conversion device further includes a sensing transistor. The first end of the sensing transistor is coupled to the connection node. The second end of the sensing transistor is coupled to the control circuit. The control end of the sensing transistor is coupled to the control circuit. The control circuit turns on the sensing transistor and senses the current value flowing through the sensing transistor. The sensing transistor is integrated in the second die.

In one embodiment of the present novel invention, the power switch is implemented by a depletion-type gallium nitride field effect transistor.

In one embodiment of the present invention, the power conversion device further includes a cascade switch. The cascade switch is coupled to the power switch and the control circuit.

Based on the above, the charge and discharge control circuit includes a bridge switch and a discharge circuit. The power switch and the bridge switch of the charge and discharge control circuit are integrated in the second die. The control circuit and the discharge circuit of the charge and discharge control circuit are integrated in the first die. The second die is produced by a process rule that meets the high voltage withstand capability. The first die is produced by a process rule that meets the low voltage withstand capability. Therefore, the charge and discharge control circuit of the present novel invention does not need to be integrated in an additional die. The number of die in the power conversion device can be reduced. In this way, under the demand for high voltage, the size of the power conversion device can be reduced.

Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. When the same element symbols appear in different drawings, they will be regarded as the same or similar elements. These embodiments are only part of the present invention and do not disclose all possible implementations of the present invention. More precisely, these embodiments are only examples within the scope of the patent application of the present invention.

Please refer to FIG. 1, which is a schematic diagram of a power conversion device according to an embodiment of the present invention. In this embodiment, the power conversion device 100 includes a safety capacitor (or X capacitor) CX, a power switch SWP, a charge and discharge control circuit 110, and a control circuit 120. The charge and discharge control circuit 110 includes a bridge switch SWB and a discharge circuit 111. The first end of the bridge switch SWB is coupled to the safety capacitor CX via a connection node ND. The discharge circuit 111 is coupled to the second end of the bridge switch SWB. The discharge circuit 111 discharges the voltage at the safety capacitor CX.

Taking the present embodiment as an example, the power conversion device 100 further includes a rectifier circuit RC and a conversion circuit TC (but the present invention is not limited thereto). The power switch SWP is arranged in the conversion circuit TC. The rectifier circuit RC can receive the AC power supply VAC and rectify the AC power supply VAC to generate the input power supply VIN. The conversion circuit TC receives the input power supply VIN and converts the input power supply VIN into the output power supply VOUT. The control circuit 120 can use the control signal SCP to control the power switch SWP. The switching operation (such as duty cycle or frequency) of the power switch SWP can determine the output result of the output power supply VOUT. In the present embodiment, the power conversion device 100 can be any type of boost converter.

In this embodiment, the control circuit 120 and the discharge circuit 111 are integrated or packaged in the first die DIE1. The power switch SWP and the bridge switch SWB are integrated or packaged in the second die DIE2. The withstand voltage capability of the second die DIE2 is higher than that of the first die DIE1.

The first die DIE1 is produced by a process rule that complies with low withstand voltage capability. The second die DIE2 is produced by a process rule that complies with high withstand voltage capability. It is worth mentioning here that the power switch SWP and the bridge switch SWB of the charge and discharge control circuit 110 are integrated in the second die DIE2. The control circuit 120 and the discharge circuit 111 of the charge and discharge control circuit 110 are integrated in the first die DIE1. Therefore, the charge and discharge control circuit 110 of the novel invention does not need to be integrated in an additional die. The number of die in the power conversion device 100 can be reduced. In this way, under the demand for high voltage, the volume of the power conversion device 100 can be reduced.

In this embodiment, the power switch SWP is implemented by a gallium nitride (GaN) field effect transistor. The bridge switch SWB is implemented by a GaN field effect transistor. Further, the power switch SWP and the bridge switch SWB are respectively implemented by enhancement-type GaN field effect transistors. Therefore, the power switch SWP and the bridge switch SWB have a higher voltage tolerance. For example, the power switch SWP and the bridge switch SWB can withstand a voltage difference greater than 600 volts.

In this embodiment, the control circuit 120 can use the control signal SCB to control the conduction or disconnection of the bridge switch SWB. The control circuit 120 can use the control signal SCD to control the discharge circuit 111. When the power conversion device 100 does not receive the AC power VAC, the discharge circuit 111 is controlled to discharge the voltage at the safety capacitor CX. When the discharge circuit 111 discharges the voltage at the safety capacitor CX, the control circuit 120 turns on the bridge switch SWB. Therefore, the discharge circuit 111 can use a reference low voltage (e.g., ground) to pull down the voltage value of the safety capacitor CX.

The power conversion device 100 further includes diodes D1, D2 and resistors R1, R2. The anode of the diode D1 is coupled to the first end of the safety capacitor CX. The anode of the diode D2 is coupled to the second end of the safety capacitor CX. The resistor R1 is coupled between the cathode of the diode D1 and the connection node ND. The resistor R2 is coupled between the cathode of the diode D2 and the connection node ND.

In this embodiment, the charge and discharge control circuit 110 further includes a charging circuit 112. The charging circuit 112 is coupled to the second end of the bridge switch SWB. The charging circuit 112 charges the voltage at the connection node ND. The charging circuit 112 is integrated in the first die DIE1. The control circuit 120 can control the charging circuit 112 using the control signal SCC. When the power conversion device 100 just receives the alternating current power VAC, the charging circuit 112 is controlled to charge the voltage at the connection node ND. When the charging circuit 112 charges the voltage at the connection node ND, the control circuit 120 turns on the bridge switch SWB. Therefore, the charging circuit 112 can use the electric energy stored in the capacitor CVCC to charge the connection node ND.

In this embodiment, when the power conversion device 100 receives the AC power VAC and the charging of the connection node ND is completed, the bridge switch SWB is disconnected.

Please refer to Figures 1 and 2. Figure 2 is a schematic diagram of the die layout of a power conversion device according to an embodiment of the present invention. In this embodiment, the first die DIE1 and the second die DIE2 are packaged in a circuit element. The first die DIE1 includes a discharge circuit 111, a charge circuit 112 and a control circuit 120. The discharge circuit 111, the charge circuit 112 and the control circuit 120 are respectively integrated in the first die DIE1. The second die DIE2 includes a bridge switch SWB and a power switch SWP. That is, the power switch SWP is integrated in the region RG1 of the second die DIE2. The bridge switch SWB is integrated in the region RG2 of the second die DIE2.

In this embodiment, the first die DIE1 includes at least pads PD1_1 to PD1_4. The second die DIE2 includes at least pads PD2_1 to PD2_12. The control circuit 120 provides the control signal SCP to the control end of the power switch SWP through the pads PD1_1 and PD2_1. The first end of the power switch SWP is coupled to at least one of the high voltage pins PN5 to PN8 of the circuit element through at least one of the pads PD2_6 to PD2_9. The second end of the power switch SWP is coupled to at least one of the low voltage pins PN1 to PN4 of the circuit element through at least one of the pads PD2_2 to PD2_5.

In this embodiment, the first end of the bridge switch SWB is coupled to the connection node ND through the pad PD2_10 and the pin PN9 of the circuit element. The charging circuit 112 is coupled to the capacitor CVCC through the pad PD1_2 and the pin PN10 of the circuit element. The second end of the bridge switch SWB is coupled to the discharge circuit 111 and the charging circuit 112 through the pads PD2_11 and PD1_3. In addition, the control end of the bridge switch SWB is coupled to the first die DIE1 through the pads PD2_12 and PD1_4. Further, the control end of the bridge switch SWB can be coupled to the control circuit 120 through the pads PD2_12 and PD1_4.

Please refer to Figures 1, 3 and 4. Figure 3 is a circuit diagram of a bridge switch and a sensing transistor according to an embodiment of the present invention. Figure 4 is a schematic diagram of a chip layout of a power conversion device according to an embodiment of the present invention. In this embodiment, the power conversion device 100 also includes a sensing transistor TS. The first end of the sensing transistor TS is coupled to the connection node ND. The second end of the sensing transistor TS is coupled to the control circuit 120. The control end of the sensing transistor TS is coupled to the manufactured circuit 120. The control circuit 120 turns on the sensing transistor TS and senses the current value IS flowing through the sensing transistor TS.

In the present embodiment, the sensing transistor TS is integrated in the second die DIE2. Furthermore, the bridge switch SWB and the sensing transistor TS are integrated in the region RG2 of the second die DIE2. In the present embodiment, the first end of the sensing transistor TS is coupled to the first end of the bridge switch SWB and the pad PD2_10. The control end of the sensing transistor TS is coupled to the control end of the bridge switch SWB and the pad PD2_12. Therefore, when the bridge switch SWB is turned on, the sensing transistor TS is turned on. The current value IB flowing through the bridge switch SWB is designed to be greater than the current value IS flowing through the sensing transistor TS. The current value IB is an integer multiple of the current value IS (e.g., IB:IS=100:1, but the present invention is not limited to this). Therefore, the control circuit 120 can obtain the current value IB flowing through the bridge switch SWB according to the current value IS flowing through the sensing transistor TS. On the other hand, when the bridge switch SWB is turned off, the sensing transistor TS is turned off.

The second end pin of the sensing transistor TS is coupled to the control circuit 120 through the pads PD2_13 and PD1_5. Therefore, when the sensing transistor TS and the bridge switch SWB are turned on, the control circuit 120 senses the current value IS flowing through the sensing transistor TS through the pads PD2_13 and PD1_5. The control circuit 120 performs an over-current protection operation according to the current value IS. In the present embodiment, the control circuit 120 includes a sensing circuit 121. The sensing circuit 121 senses the current value IS flowing through the sensing transistor TS and provides a sensing result. The control circuit 120 performs an over-current protection operation according to the sensing result.

Please refer to Figures 1, 5 and 6. Figure 5 is a circuit diagram of a bridge switch and a voltage divider circuit according to an embodiment of the present invention. Figure 6 is a schematic diagram of a die layout of a power conversion device according to an embodiment of the present invention. In this embodiment, the power conversion device 100 also includes a voltage divider circuit 130. The voltage divider circuit 130 is coupled to the connection node ND and the control circuit 120. The voltage divider circuit 130 generates a feedback voltage VFB according to the voltage value at the connection node ND. The control circuit 120 determines the voltage value of the safety capacitor CX according to the feedback voltage VFB.

In the present embodiment, the voltage divider circuit 130 is integrated in the second die DIE2. Further, the bridge switch SWB and the voltage divider circuit 130 are integrated in the region RG2 of the second die DIE2. In the present embodiment, the voltage divider circuit 130 includes voltage divider resistors RD1 and RD2. The first end of the voltage divider resistor RD1 is coupled to the first end of the bridge switch SWB and the pad PD2_10. The second end of the voltage divider resistor RD1 is coupled to the control circuit 120 through the pads PD2_14 and PD1_6. The first end of the voltage divider resistor RD2 is coupled to the second end of the voltage divider resistor RD1. The second end of the voltage dividing resistor RD2 is coupled to the ground pad PD2_GND of the second die DIE2 and the ground pad PD1_GND of the first die DIE1.

In this embodiment, the voltage divider circuit 130 divides the voltage value at the connection node ND by the resistance value of the voltage divider resistor RD1 and the resistance value of the voltage divider resistor RD2 to generate the feedback voltage VFB. The voltage divider circuit 130 outputs the feedback voltage VFB through the pad PD2_14. The control circuit 120 receives the feedback voltage VFB through the pad PD1_6, and performs at least one of an over-voltage protection operation, an under-voltage protection operation, and a connection state between the power conversion device 100 and the AC power source VAC according to the feedback voltage VFB.

In this embodiment, the power conversion device 100 further includes a resistor RS. The resistor RS is coupled between the first terminal and the control terminal of the bridge switch SWB. The resistor RS is integrated in the region RG2 of the second die DIE2.

Please refer to Figures 1, 7 and 8. Figure 7 is a circuit diagram of a bridge switch, a sensing transistor and a voltage divider circuit drawn according to an embodiment of the present invention. Figure 8 is a schematic diagram of the chip layout of a power conversion device drawn according to an embodiment of the present invention. In this embodiment, the power conversion device 100 also includes a sensing transistor TS and a voltage divider circuit 130. In this embodiment, the sensing transistor TS and the voltage divider circuit 130 are integrated in the second chip DIE2. Further, the bridge switch SWB, the sensing transistor TS and the voltage divider circuit 130 are integrated in the region RG2 of the second chip DIE2. The implementation method of the sensing transistor TS has been clearly explained in the embodiments of Figures 1, 3 and 4, so it will not be repeated here. The implementation of the voltage divider circuit 130 has been clearly described in the embodiments of FIG. 1 , FIG. 5 , and FIG. 6 , and will not be repeated here.

Please refer to Figures 1, 9 and 10. Figure 9 is a circuit diagram of a power switch and a cascade switch according to an embodiment of the present invention. Figure 10 is a schematic diagram of a die layout of a power conversion device according to an embodiment of the present invention. In this embodiment, the power switch SWP is implemented by a depletion type GaN field effect transistor. Therefore, the power conversion device 100 also includes a cascode switch SWC. The cascade switch SWC is coupled to the power switch SWP and the control circuit 120. The cascade switch SWC and the power switch SWP form a cascade switch circuit. The cascade switch SWC is used to determine the switching operation of the cascade switch circuit.

In this embodiment, the control end of the power switch SWP receives the bias value VB. Therefore, the power switch SWP is controlled to be in a normal ON state. The first end of the cascade switch SWC is coupled to the second end of the power switch SWP through at least one of the pads PD3_2, PD3_3, and PD2_2~PD2_5. The control circuit 120 includes a drive circuit DC. The drive circuit DC provides a control signal SCP based on a pulse-width modulation (PWM) signal, and provides the control signal SCP to the cascade switch SWC through the pad PD3_1. Therefore, the cascade switch circuit performs a switching operation based on the control signal SCP.

In the present embodiment, the bridge switch SWB and the voltage divider circuit 130 are integrated in the region RG2 of the second die DIE2 (but the present invention is not limited thereto). Therefore, the region RG2 of the second die DIE2 also includes the pads PD2_10~PD2_12 and PD2_14. In some embodiments, only the bridge switch SWB is integrated in the region RG2 of the second die DIE2. Therefore, the region RG2 of the second die DIE2 also includes the pads PD2_10~PD2_12. In some embodiments, the bridge switch SWB and the sensing transistor TS are integrated in the region RG2 of the second die DIE2 (but the present invention is not limited thereto). Therefore, the region RG2 of the second die DIE2 also includes the pads PD2_10~PD2_13. In some embodiments, the bridge switch SWB, the sensing transistor TS, and the voltage divider circuit 130 are integrated in the region RG2 of the second die DIE2. Therefore, the region RG2 of the second die DIE2 further includes pads PD2_10-PD2_14.

Please refer to FIG. 11, which is a circuit diagram of a power switch, a cascade switch, and a charge-discharge control circuit according to an embodiment of the present invention. In this embodiment, the implementation contents of the power switch SWP and the cascade switch SWC have been clearly described in the embodiments of FIG. 1, FIG. 9, and FIG. 10, and will not be repeated here. In this embodiment, unlike FIG. 1, the charge-discharge control circuit 110 is coupled to a safety capacitor or a connection node (such as the safety capacitor CX or the connection node ND shown in FIG. 1) through the power switch SWP. Since the power switch SWP is in a normally conducting state. Therefore, the charge-discharge control circuit 110 can perform discharge operations on the safety capacitor and/or charge operations on the connection node through the power switch SWP.

In summary, the power conversion device of the present invention includes a safety capacitor, a power switch SWP, a charge and discharge control circuit, and a control circuit. The charge and discharge control circuit includes a bridge switch and a discharge circuit. The power switch and the bridge switch of the charge and discharge control circuit are integrated in the second die. The control circuit and the discharge circuit of the charge and discharge control circuit are integrated in the first die. The second die is produced by a process rule that meets the high voltage withstand capability. The first die is produced by a process rule that meets the low voltage withstand capability. Therefore, the charge and discharge control circuit of the present invention does not need to be integrated in an additional die. The number of die in the power conversion device can be reduced. In this way, under the demand for high voltage, the size of the power conversion device can be reduced.

Although the novel creation has been disclosed as above by way of embodiments, they are not intended to limit the novel creation. Any person with ordinary knowledge in the relevant technical field may make slight changes and modifications without departing from the spirit and scope of the novel creation. Therefore, the protection scope of the novel creation shall be subject to the scope defined in the attached patent application.

100: Power conversion device 110: Charge and discharge control circuit 111: Discharge circuit 112: Charge circuit 120: Control circuit 121: Sensing circuit 130: Voltage divider circuit CVCC: Capacitor CX: Safety capacitor D1, D2: Diode DC: Drive circuit DIE1: First die DIE2: Second die IB, IS: Current value ND: Connection node PD1_1~PD1_6, PD2_1~PD2_14, PD3_1~PD3_3: Pads PD1_GND, PD2_GND: Ground pads PN1~PN4: Low voltage pins PN5~PN8: High voltage pins PN9, PN10: pins R1, R2, RS: resistors RC: rectifier circuit RD1, RD2: voltage divider resistors RG1, RG2: regions SCB, SCC, SCD, SCP: control signals SWB: bridge switch SWC: cascade switch SWP: power switch TC: conversion circuit TS: sensing transistor VAC: AC power VFB: feedback voltage VIN: input power VOUT: output power

FIG. 1 is a schematic diagram of a power conversion device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a chip layout of a power conversion device according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a circuit of a bridge switch and a sensing transistor according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a chip layout of a power conversion device according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a circuit of a bridge switch and a voltage divider circuit according to an embodiment of the present invention. FIG. 6 is a schematic diagram of a chip layout of a power conversion device according to an embodiment of the present invention. FIG. 7 is a circuit diagram of a bridge switch, a sensing transistor, and a voltage divider circuit according to an embodiment of the present invention. FIG. 8 is a circuit diagram of a power converter according to an embodiment of the present invention. FIG. 9 is a circuit diagram of a power switch and a cascade switch according to an embodiment of the present invention. FIG. 10 is a circuit diagram of a power converter according to an embodiment of the present invention. FIG. 11 is a circuit diagram of a power switch, a cascade switch, and a charge-discharge control circuit according to an embodiment of the present invention.

100: Power conversion device

110: Charging and discharging control circuit

111: Discharge circuit

112: Charging circuit

120: Control circuit

121: Sensing circuit

CVCC: Capacitor

CX: Safety capacitor

D1, D2: diodes

DIE1: First grain

DIE2: Second die

ND: Connection Node

R1, R2: resistors

RC: Rectifier circuit

SCB, SCC, SCD, SCP: control signals

SWB: Bridge switch

SWP: Power switch

TC:Conversion circuit

VAC: alternating current power

VIN: Input power

VOUT: output power

Claims (10)

A power conversion device, comprising: a safety capacitor; a power switch; a charge-discharge control circuit, comprising: a bridge switch, a first end of the bridge switch coupled to the safety capacitor via a connection node; and a discharge circuit coupled to a second end of the bridge switch, configured to discharge a voltage located at the safety capacitor; and a control circuit coupled to the power switch and the charge-discharge control circuit, wherein the control circuit and the discharge circuit are integrated in a first die, wherein the power switch and the bridge switch are integrated in a second die, and wherein the withstand voltage capability of the second die is higher than the withstand voltage capability of the first die. A power conversion device as described in claim 1, wherein the power switch is implemented by a gallium nitride field effect transistor. A power conversion device as described in claim 1, wherein the bridge switch is implemented by a gallium nitride field effect transistor. A power conversion device as described in claim 1, wherein when the discharge circuit discharges the voltage at the safety capacitor, the control circuit turns on the bridge switch. In the power conversion device as described in claim 1, the charge-discharge control circuit further includes: A charging circuit coupled to the second end of the bridge switch, configured to charge the voltage at the connection node, wherein the charging circuit is integrated in the first die. A power conversion device as described in claim 5, wherein when the charging circuit charges the voltage at the connection node, the control circuit turns on the bridge switch. The power conversion device as described in claim 1 further includes: A voltage divider circuit coupled to the connection node and the control circuit, configured to generate a feedback voltage according to the voltage value at the connection node, wherein the control circuit determines the voltage value of the safety capacitor according to the feedback voltage, and wherein the voltage divider circuit is integrated in the second die. The power conversion device as described in claim 1 further comprises: a sensing transistor, wherein the first end of the sensing transistor is coupled to the connection node, the second end of the sensing transistor is coupled to the control circuit, the control end of the sensing transistor is coupled to the control circuit, wherein the control circuit turns on the sensing transistor and senses the current value flowing through the sensing transistor, and wherein the sensing transistor is integrated in the second die. A power conversion device as described in claim 1, wherein the power switch is implemented by a depletion type gallium nitride field effect transistor. The power conversion device as described in claim 9 further includes: A cascade switch coupled to the power switch and the control circuit.

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