CN-121984323-A - High-side driving circuit based on level shift charge pump and solid-state power controller

CN121984323ACN 121984323 ACN121984323 ACN 121984323ACN-121984323-A

Abstract

The invention discloses a high-side driving circuit and a solid-state power controller based on a level shift charge pump, and belongs to the technical field of power electronics. The circuit comprises a power main circuit, a grid driving circuit, a high Bian Chuneng circuit, a level shift charge pump circuit and a turn-off active bleeder circuit. The power main circuit adopts a high-side N-channel MOSFET structure which is connected in series back to back, the level shift charge pump circuit finishes level shift by controlling charge-discharge circulation of the flying capacitor, continuously transfers low-voltage side energy to the high-side bootstrap capacitor to maintain continuous power supply of grid drive of the power tube, and the active bleeder circuit is turned off to establish an energy bleeder path when power distribution is turned off, rapidly releases bootstrap capacitor charge, provides a freewheeling circuit for an inductive load through a freewheeling diode and clamps load voltage to ground potential. The invention solves the problem that the traditional high-side bootstrap capacitor cannot meet the continuous conduction of the 100% duty ratio, and improves the driving performance of the solid-state power controller.

Inventors

YANG FAN
LIU XIAOYUAN
ZHANG WEI
WANG QINGCHAO
GAO SHENG
Jin Bopi
CHI HAODONG

Assignees

中国科学院沈阳自动化研究所

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (8)

1. The high-side driving circuit based on the level shift charge pump is characterized by comprising a power main circuit, a grid driving circuit, a high Bian Chuneng circuit, a level shift charge pump circuit and a turn-off active bleeder circuit; The power main circuit comprises a first power switch tube Q5 and a second power switch tube Q6, wherein one end of the first power switch tube Q5 is connected with a bus power supply, the other end of the first power switch tube Q5 is connected with one end of the second power switch tube Q6, and the other end of the second power switch tube Q6 is connected with a load for realizing the power-on and power-off control of the load and simultaneously has the functions of preventing reverse current backflow and protecting the bus power supply from reverse connection; The grid driving circuit is connected with the power main circuit and is used for outputting a high-side driving signal, driving the first power switching tube Q5 and the second power switching tube Q6 to be turned on and off, and realizing soft start of the turning-on process of the first power switching tube Q5 and the second power switching tube Q6; the high-side energy storage circuit is connected with the grid driving circuit and used for providing a high-side suspension power supply for the grid driving circuit; The level shift charge pump circuit is connected with the high-side energy storage circuit and is used for realizing the lifting of the low-voltage side power supply voltage and continuously transferring energy into the high-side energy storage circuit so as to maintain the continuous power supply of the grid drive of the first power switch tube Q5 and the second power switch tube Q6, thereby realizing the continuous conduction of the first power switch tube Q5 and the second power switch tube Q6; The turn-off active bleeder circuit is respectively connected with the power main circuit and the high-side energy storage circuit, and is used for conducting the bleeder path when the first power switch tube Q5 and the second power switch tube Q6 of the power main circuit are turned off, releasing charges stored in the high-side energy storage circuit, providing a follow current path for an inductive load, and clamping the load in a turn-off holding state to the ground potential.
2. The level shifting charge pump based high side drive circuit of claim 1, wherein the first power switch Q5 and the second power switch Q6 are configured in a back-to-back series configuration allowing bi-directional current to flow when the power main circuit is on and blocking reverse current from the load output with the body diodes in the first power switch Q5 and the second power switch Q6 in anti-series when the power main circuit is off.
3. The high-side driving circuit based on the level shift charge pump according to claim 2, wherein the first power switch tube Q5 and the second power switch tube Q6 are N-channel MOSFETs, a source electrode of the first power switch tube Q5 is connected with a source electrode of the second power switch tube Q6 to form a common source electrode node, the common source electrode node is connected to the high Bian Chuneng circuit and the high-side floating VS, a drain electrode of the first power switch tube Q5 is connected to an input end V BUS of the bus power supply, a drain electrode of the second power switch tube Q6 is connected to a load end, a grid electrode of the first power switch tube Q5 is connected with a grid electrode of the second power switch tube Q6 to form a common grid electrode node, and the common grid electrode node is connected to an output end of the grid driving circuit.
4. The high-side driving circuit based on the level shift charge pump as claimed in claim 3, wherein the gate driving circuit comprises a gate resistor R3, an accelerated turn-off diode D4, a gate-source capacitor C3 and a gate-source resistor R4; The grid resistor R3 is connected in series between the grid driving output HO and the common grid node, the accelerated turn-off diode D4 is connected in inverse parallel to two ends of the grid resistor R3, the cathode of the accelerated turn-off diode D4 is connected with the grid driving output HO, the grid source resistor R4 is connected between the common grid node and the common source node, the grid source capacitor C3 is connected in parallel with the grid source resistor R4 and is connected between the common grid node and the common source node, and the output end of the grid driving circuit is arranged on a common connection point of the grid source resistor R4, the grid resistor R3 and the anode of the accelerated turn-off diode D4.
5. The high-side driving circuit based on the level shift charge pump according to claim 3, wherein the high Bian Chuneng circuit is a high-side bootstrap capacitor C2, an anode of the high-side bootstrap capacitor C2 is used as the high-side floating power supply terminal and connected to a positive output terminal of the charge pump circuit and a high-side power supply input terminal VB of the gate driving circuit, a cathode of the high-side bootstrap capacitor C2 is used as the high-side floating ground terminal and connected to the common-source node of the power main circuit and a high-side floating ground VS of the gate driving circuit.
6. The high-side drive circuit based on a level shift charge pump according to claim 5, wherein the level shift charge pump circuit comprises a flying capacitor C1, an input diode D1, an output diode D2, a first charge pump switch transistor Q1, a second charge pump switch transistor Q2, a third charge pump switch transistor Q3, and a pull-up resistor R1; The input diode D1 is connected with a low-voltage direct-current power supply LDO at the anode, the cathode of the input diode D1 is connected with the anode of the flying capacitor C1, the anode of the output diode D2 is connected with the anode of the flying capacitor C1, the cathode of the output diode D2 is connected with the anode of the high-side bootstrap capacitor C2, the source electrode of the first charge pump switching tube Q1 and the source electrode of the second charge pump switching tube Q2 are both connected with the system ground GND, the grid electrode of the first charge pump switching tube Q1 and the grid electrode of the second charge pump switching tube Q2 are both connected with a square wave periodic signal OSC, the drain electrode of the first charge pump switching tube Q1 is connected with the cathode of the flying capacitor C1 and used for pulling down the cathode of the flying capacitor C1 to the ground in a charging stage, the source electrode of the third charge pump switching tube Q3 is connected with the cathode of the flying capacitor C1, the drain electrode of the third charge pump switching tube Q3 is connected with the drain electrode of the high-side bootstrap capacitor C2, the drain electrode of the third charge pump switching tube Q2 is connected with the anode of the second charge pump Q2, and the second charge pump Q1 is turned off simultaneously, and the second charge pump Q2 is turned on and turned off.
7. The high-side drive circuit based on a level shift charge pump according to claim 5, wherein the turn-off active bleeder circuit comprises a bleeder resistor R2, a bleeder switching tube Q4, an inverter U1 and a freewheeling diode D3; One end of the bleeder resistor R2 is connected to the positive electrode of the high-side bootstrap capacitor C2, the other end of the bleeder resistor R2 is connected to the drain electrode of the bleeder switch tube Q4, the source electrode of the bleeder switch tube Q4 is connected to the system ground GND, the anode of the freewheeling diode D3 is connected to the negative electrode of the high-side bootstrap capacitor C2, the cathode of the freewheeling diode D3 is connected to the positive electrode of the high-side bootstrap capacitor C2, and the output end of the inverter U1 is connected to the grid electrode of the bleeder switch tube Q4; The turn-off active bleeder circuit is configured such that when in a "power distribution off" state, the bleeder switch Q4 is turned on, creating a first discharge path from the positive pole of the high-side bootstrap capacitor C2 to ground via the bleeder resistor R2 to discharge the charge of the high-side bootstrap capacitor C2, while creating a second bleeder path from the load to ground via the high-side floating ground VS, the freewheeling diode D3, and the bleeder resistor R2, and clamping the load terminal voltage to ground potential.
8. The solid-state power controller is characterized by comprising a main controller circuit, a voltage and current detection circuit and the high-side driving circuit based on the level shift charge pump, which is disclosed in any one of claims 1-7; The main controller circuit is respectively connected with the voltage and current detection circuit and the high-side driving circuit based on the level shift charge pump and is used for generating control signals in a power distribution on state or a power distribution off state, one end of the voltage and current detection circuit is connected to the load end, the other end of the voltage and current detection circuit is connected to the high-side driving circuit based on the level shift charge pump and is used for collecting output voltage and current signals of the load and feeding the output voltage and current signals back to the main controller circuit, so that the main controller can monitor load working conditions in real time and realize turn-off protection when abnormal states are identified.

Description

High-side driving circuit based on level shift charge pump and solid-state power controller Technical Field The invention belongs to the technical field of power electronics, and particularly relates to a high-side driving circuit based on a level shift charge pump and a solid-state power controller. Background The Solid state power controller (SSPC, ‌ Solid-State Power Controller ‌) is a novel intelligent Solid state switch, and the core of the Solid state power controller is that a power semiconductor device is used for replacing a mechanical contact of a traditional relay so as to realize on-off control of load distribution, thereby having the remarkable advantages of no mechanical abrasion, long service life, vibration impact resistance and the like. In addition, the SSPC also integrates intelligent control and diagnosis functions, and can monitor the load state in real time and identify faults such as overload, short circuit and the like. With their excellent performance, high reliability, and extremely fast protection response speed, SSPCs are increasingly being widely used in critical power distribution systems such as aerospace. In the topology of SSPCs, a "high side drive" architecture is typically employed, i.e., a switching device is placed between the power supply anode and the load. The structure ensures that the load is connected to the ground in the off state, effectively avoids the risk of electrification of the load end, improves the safety of the system, and accords with the safety specifications of most electrical systems. In the selection of the power Semiconductor device, an N-channel MOSFET device (NMOS, N-CHANNEL METAL-Oxide-Semiconductor ‌) has lower on-resistance, superior switching performance and higher cost advantage than a P-channel MOSFET device (PMOS, P-CHANNEL METAL Oxide Semiconductor ‌, P-channel metal Oxide Semiconductor). However, since the NMOS source of the high side drive is connected to the load, the source potential will rise to the supply voltage with the load voltage when the switch is turned on. In order to maintain the on state of the NMOS, the driving circuit needs to generate a gate control voltage higher than the power supply voltage by at least one threshold voltage level. The existing high-side NMOS driving scheme mainly comprises the following three types: 1. in the traditional bootstrap circuit, a diode and a capacitor are utilized, the capacitor is charged by a power supply during the turn-off period of a switching tube, and the grid electrode is driven by the energy stored by the capacitor when the switching tube is turned on. The scheme has a simple structure, but because the bootstrap capacitor has limited energy storage, the long-time grid driving power supply cannot be maintained, and the capacitor needs to be recharged by periodically turning off a switching tube. This is not consistent with an application scenario where SSPCs require 100% duty cycle to be continuously on. 2. And in the isolated power supply scheme, an isolated DC/DC (Direct Current to Direct Current) module is used for independently supplying power to the high-side driving circuit. The scheme can provide stable floating voltage without being limited by duty ratio, but the DC/DC module has large volume and high cost, and is not beneficial to miniaturized integration of the system. In addition, the DC/DC module introduces additional electromagnetic interference (EMI, electromagnetic Interference ‌) that increases the difficulty of system EMC design. 3. And the direct-drive charge pump is used for directly applying a driving voltage higher than a power supply voltage to the NMOS grid electrode through a charge pump circuit. However, since the output impedance of the charge pump itself is high, the current driving capability is limited, resulting in a slow switching speed of the NMOS. In addition, to meet the driving requirement of the high-power NMOS, the design of the driving circuit is often complex. In summary, how to realize 100% duty cycle continuous turn-on of the high-side NMOS, and at the same time, have strong current driving capability and low circuit complexity is a key of the design of the high-performance solid-state power controller. The invention provides a high-side driving architecture based on a level shift charge pump, which is different from a direct driving mode of the charge pump, and continuously charges a bootstrap capacitor at a floating potential by using the charge pump. The design allows the power switch tube to be driven by adopting a standard high-speed grid driving chip, so that the design complexity is effectively reduced and the reliability is improved. Disclosure of Invention Aiming at the defects of the prior art, the application provides a high-side driving circuit and a solid-state power controller based on a level shift charge pump, solves the problems that the traditional bootstrap circuit cannot meet the continuous conduction of a 100% duty rati