CN101753018B - High-voltage side driving circuit - Google Patents

Abstract

A high-voltage side driving circuit includes a bridge rectifier, a bootstrap capacitor, a signal generator, and a latch circuit. The bootstrap capacitor is coupled to the source of the high-voltage side transistor, the bridge rectifier is coupled to the signal generator, the signal generator has a first pulse output terminal and a second pulse output terminal, wherein the first pulse output terminal or the second pulse output terminal outputs a pulse signal at intervals of a time difference, and the latch circuit has a setting terminal, a reset terminal, and an output terminal, wherein the setting terminal is coupled to the first pulse output terminal, the reset terminal is coupled to the second pulse output terminal, and the output terminal is coupled to the gate of the high-voltage side transistor.

Description

High side drive circuit

technical field

The present invention relates to a driving circuit, in particular to a high voltage side driving circuit.

Background technique

With the rapid development of technology and the vigorous development of the electronic industry, power converters have been widely used in people's daily life, such as power supplies, motor drivers and so on. Today, many power converters use a high-side driver to control a voltage source coupled to the load.

Please refer to FIG. 1 , which discloses an equivalent circuit diagram of a conventional high side driver. In FIG. 1 , the high-side transistor 10 is coupled to the low-side transistor 20 . When the high-side transistor 10 is turned off and the low-side transistor 20 is turned on, the capacitor 30 can be charged. On the other hand, the control transistor 45 is turned off so that the floating voltage Vcc is transmitted from the transistor 41 to the high-side transistor 10 . However, this high-side driver is less stable in high-voltage and high-frequency applications.

Therefore, based on the above reasons, there is a need for a new high-side driving circuit, which is suitable for high-voltage applications and effectively improves the stability.

Contents of the invention

The purpose of the present invention is to provide a new high voltage side drive circuit.

In order to solve the above technical problems, the present invention adopts the following technical solutions: a high voltage side drive circuit, including a bridge rectifier, a bootstrap capacitor, a signal generator and a latch circuit. The bridge rectifier includes a first diode, a second diode, a third diode and a fourth diode. The first diode has a first anode and a first cathode, the second diode has a second anode and a second cathode, wherein the second cathode is coupled to the first anode, and the second anode is coupled to the source of the high-voltage side transistor and a drain of the low-side transistor. The third diode has a third anode and a third cathode, wherein the third cathode is coupled to the first cathode; the fourth diode has a fourth anode and a fourth cathode, wherein the fourth cathode is coupled to the third anode, And the fourth anode is coupled to the second anode. The bootstrap capacitor has a positive terminal and a negative terminal, wherein the positive terminal is coupled to the third cathode and the first cathode, and the negative terminal is coupled to the fourth anode, the second anode and the source of the high-side transistor. The signal generator includes a first pulse output terminal and a second pulse output terminal. The first pulse output end can generate a first pulse signal periodically. The second pulse output end can generate a second pulse signal periodically, wherein when the second pulse output end generates the second pulse signal, the first pulse output end stops generating the first pulse signal; when the first pulse output end generates the second pulse signal When there is a pulse signal, the second pulse output end stops generating the second pulse signal. The latch circuit includes a setting terminal, a reset terminal and an output terminal. The setting terminal can receive the first pulse signal. The reset terminal can receive the second pulse signal. The output end can output a digital signal to a gate of the high-voltage side transistor according to the first pulse signal or the second pulse signal, wherein the output end sets the digital signal at a first voltage level according to the first pulse signal; output The terminal sets the digital signal at a second voltage level according to the second pulse signal, wherein the first voltage level is greater than the second voltage level.

Therefore, the high-side driving circuit can drive the high-side transistor and the low-side transistor.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. From the above technical solution, the present invention can achieve considerable technical progress and practicality, and has wide industrial application value, and it has at least the following advantages:

(1) Bootstrap capacitors can be charged without additional bias.

(2) Prevent noise interference.

To sum up, the novel high-voltage side driver of the present invention has the feature of preventing noise interference, and the high-voltage side driver can be used in power circuits or other similar technical links. The present invention has the above-mentioned many advantages and practical value, it has great improvement no matter in circuit structure or function, has significant progress in technology, and has produced easy-to-use and practical effect, and compared with existing anti-noise The component has enhanced and outstanding multiple functions, so it is more suitable for practical use, and has wide application value in the industry. It is a novel, progressive and practical new technology.

The following examples will be used to describe the above description and the following embodiments in detail, and provide further explanations for the present invention.

Description of drawings

In order to make the above content and other objects, features, advantages and embodiments of the present invention more obvious and understandable, the detailed description of the accompanying drawings is as follows:

FIG. 1 is an equivalent circuit diagram of a conventional high voltage side driving circuit.

FIG. 2 is an equivalent circuit diagram of a high-side driver according to an embodiment of the present invention.

FIG. 3 is a timing diagram of a high voltage side driving circuit according to an embodiment of the present invention.

The main component symbols are explained as follows:

10: High-voltage side transistor 20: Low-voltage side transistor

30: capacitor 41: transistor

45: Control transistor 200: High voltage side drive circuit

210: bridge rectifier 212: first diode

214: second diode 216: third diode

218: Fourth Diode 220: Bootstrap Capacitor

230: Signal generator 231: The first pulse output terminal

232: Second pulse output terminal 240: Latch circuit

250: fifth diode 260: voltage source

270: High side transistor 280: Low side transistor

P1: The first pulse signal P2: The second pulse signal

Q: output terminal R: reset terminal

S: Setting terminal ΔT: Time difference

V _H : high potential V _L : low potential

Detailed ways

In order to make the description of the present invention more detailed and complete, please refer to the drawings and various embodiments, and the same numbers in the drawings represent the same components. On the other hand, well-known circuit components have not been described in the embodiments in order not to limit the invention unnecessarily.

Please refer to FIG. 2 , which discloses an equivalent circuit diagram of a high side driver circuit (High side driver) according to an embodiment of the present invention. In FIG. 2 , the high voltage side driving circuit 200 may include a bridge rectifier 210 , a bootstrap capacitor 220 , a signal generator 230 and a latch circuit 240 . The bridge rectifier 210 may include a first diode 212 , a second diode 214 , a third diode 216 and a fourth diode 218 . Wherein, the first diode 212 has a first anode and a first cathode. The second diode 214 has a second anode and a second cathode, wherein the second cathode of the second diode 214 is coupled to the first anode of the first diode 212, and the second anode of the second diode 214 It is coupled to a source of a high side transistor (high side transistor) 270 and a drain of a low side transistor (low side transistor) 280 . The third diode 216 has a third anode and a third cathode, wherein the third cathode of the third diode 216 is coupled to the first cathode of the first diode 212 . The fourth diode 218 has a fourth anode and a fourth cathode, wherein the fourth cathode of the fourth diode 218 is coupled to the third anode of the third diode 216, and the fourth cathode of the fourth diode 218 The four anodes are coupled to the second anode of the second diode 214 . Moreover, both ends of the bootstrap capacitor 220 can be divided into a positive terminal and a negative terminal, wherein the positive terminal of the bootstrap capacitor 220 is coupled to the third cathode of the third diode 216 and the first cathode of the first diode 212. a cathode, and the negative terminal of the bootstrap capacitor 220 is coupled to the fourth anode of the fourth diode 218 , the second anode of the second diode 214 and the source of the high-side transistor 270 . The signal generator 230 has a first pulse output terminal 231 and a second pulse output terminal 232, wherein the first pulse output terminal 231 is coupled to the second cathode of the second diode 214 and the first anode of the first diode 212, And the second pulse output terminal 232 is coupled to the fourth cathode of the fourth diode 218 and the third anode of the third diode 216 . The latch circuit 240 has a set terminal S, a reset terminal R and an output terminal Q, wherein the set terminal S is coupled to the first pulse output terminal 231, the reset terminal R is coupled to the second pulse output terminal 232, and the output terminal Q is coupled to connected to the gate of the high-side transistor 270 . In one embodiment, the output terminal Q can be coupled to the gate of the high-side transistor 270 via a voltage-resistant capacitor or a voltage-resistant transistor.

It should be noted that, in the signal generator 230, the first pulse output terminal 231 can periodically generate the first pulse signal. The second pulse output terminal 232 can periodically generate a second pulse signal. When the second pulse output end generates the second pulse signal, the first pulse output end stops generating the first pulse signal; when the first pulse output end generates the first pulse signal, the second pulse output end stops generating the second pulse signal.

In terms of circuit configuration, the first pulse output terminal 231 may have a transistor and (or) a capacitor, and the second pulse output terminal 232 may also have a transistor and (or) capacitor.

In the latch circuit 240, the setting terminal S can receive the first pulse signal. The reset terminal R can receive the second pulse signal. The output terminal Q can output a digital signal to the gate of the high-voltage side transistor according to the first pulse signal or the second pulse signal, wherein the output terminal Q can set the digital signal at the first voltage level according to the first pulse signal; In addition, the output terminal Q can set the digital signal at a second voltage level according to the second pulse signal, wherein the first voltage level is greater than the second voltage level.

In the high voltage side drive circuit 200 of this embodiment, if the first pulse output terminal 2315 outputs the first pulse signal, and the second pulse output terminal 232 does not output the second pulse signal, the output terminal Q outputs the first voltage level digital signal (high potential), so that the high voltage side transistor 270 is turned on; otherwise, if the second pulse output terminal 232 outputs the second pulse signal, and the first pulse output terminal 231 does not output the first pulse signal, then the output terminal Q outputs the first pulse signal. The digital signal of two voltage levels (low potential) turns off the high-side transistor 270 .

It should be noted that, regardless of whether the high-side transistor 270 and/or the low-side transistor 280 are turned off or turned on, the first pulse signal and/or the second pulse signal can charge the bootstrap capacitor 220 without additional bias. pressure.

Please continue to refer to FIG. 2 , the high voltage side driving circuit 200 may optionally include a voltage source 260 and a fifth diode 250 . The fifth diode 250 has a fifth anode and a fifth cathode, wherein the fifth anode of the fifth diode 250 is coupled to the voltage source 260, and the fifth cathode of the fifth diode 250 is coupled to the third diode 216 and the first cathode of the first diode 212.

It should be noted that, in the high-side driving circuit of this embodiment, if the high-side transistor 270 is turned off and the low-side transistor 280 is turned on, the voltage source 260 can charge the bootstrap capacitor 220 .

In order to make the description of the present invention more detailed and complete, please refer to FIG. 3 , which discloses a timing diagram of a high-side driving circuit 200 according to an embodiment of the present invention. In FIG. 3 , when the first pulse output terminal 231 outputs the first pulse signal P1 at intervals of a time difference ΔT, the second pulse output terminal 232 does not output the second pulse signal P2, so that the output terminal Q outputs a digital signal with a high potential VH signal. In addition, the first pulse output terminal 231 outputs the first pulse signal P1 intermittently, so that the output terminal Q can output the digital signal of the logic high potential VH stably.

On the other hand, when the second pulse output terminal 232 outputs the second pulse signal P2 at intervals of a time difference ΔT, the first pulse output terminal 231 does not output the first pulse signal P1, so that the output terminal Q outputs a digital signal with a low potential VL signal. In addition, the second pulse output terminal 232 intermittently outputs the second pulse signal P2, so that the output terminal Q can stably output the digital signal of the low potential VL.

It is worth noting that, in the high-voltage side drive circuit of this embodiment, since the first pulse output terminal 231 outputs the first pulse signal P1 at intervals of a time difference ΔT, each first pulse signal P1 can make the digital value of the output terminal Q The signal is set at the first voltage level (high level). Alternatively, the second pulse output terminal 232 outputs the second pulse signal P2 at intervals of a time difference ΔT, wherein each second pulse signal P2 can set the digital signal of the output terminal Q at the second voltage level (low level) . Thereby, the output terminal Q stably outputs the correct potential value, effectively preventing noise from interfering with the latch circuit.

The description and application of the invention herein is illustrative and is not intended to limit the scope of the invention to the above-described embodiments. Variations and changes to the embodiments disclosed herein are possible, and substitutions and equivalents for various components of the embodiments are known to those of ordinary skill in the art. It should be clear to those skilled in the art that the present invention can be realized in other forms, structures, arrangements, proportions, and with other components, materials and parts without departing from the spirit or essential characteristics of the present invention. Other modifications and changes may be made to the embodiments disclosed herein without departing from the scope and spirit of the invention.

Claims (6)

1. A high-voltage side drive circuit, characterized in that, comprising: A bridge rectifier comprising; a first diode having a first anode and a first cathode; A second diode having a second anode and a second cathode, wherein the second cathode is coupled to the first anode, and the second anode is coupled to a source of a high-voltage side transistor and a low-voltage side transistor a drain of a third diode having a third anode and a third cathode, wherein the third cathode is coupled to the first cathode; and a fourth diode having a fourth anode and a fourth cathode, wherein the fourth cathode is coupled to the third anode, and the fourth anode is coupled to the second anode; A bootstrap capacitor having a positive terminal and a negative terminal, wherein the positive terminal is coupled to the third cathode and the first cathode, and the negative terminal is coupled to the fourth anode, the second anode and the high-side transistor the source; A signal generator, comprising: a first pulse output terminal connected to the first anode for periodically generating a first pulse signal; and A second pulse output terminal, connected to the fourth cathode, for periodically generating a second pulse signal, wherein when the second pulse output terminal generates the second pulse signal, the first pulse output terminal stops generating the first pulse signal; when the first pulse output end generates the first pulse signal, the second pulse output end stops generating the second pulse signal; and A latch circuit, comprising: a setting terminal for receiving the first pulse signal; a reset terminal for receiving the second pulse signal; and An output terminal, used to output a digital signal to a gate of the high-voltage side transistor according to the first pulse signal or the second pulse signal, wherein the output terminal sets the digital signal according to the first pulse signal At a first voltage level; the output terminal sets the digital signal at a second voltage level according to the second pulse signal, wherein the first voltage level is greater than the second voltage level. 2. The high voltage side drive circuit as claimed in claim 1, wherein when the first pulse output terminal outputs the first pulse signal at intervals of a time difference, and the second pulse output terminal does not output the second pulse signal , then the output terminal outputs the digital signal with the first voltage level, so that the high-voltage side transistor is turned on. 3. The high voltage side drive circuit as claimed in claim 1, wherein when the second pulse output end outputs the second pulse signal at intervals of a time difference, and the first pulse output end does not output the first pulse signal , the output end outputs the digital signal with the second voltage level, so that the high-voltage side transistor is turned off. 4. The high voltage side driving circuit as claimed in claim 1, wherein the first pulse signal or the second pulse signal charges the bootstrap capacitor. 5. The high voltage side drive circuit according to claim 1, further comprising: a voltage source; and A fifth diode has a fifth anode and a fifth cathode, wherein the fifth anode is coupled to the voltage source, and the fifth cathode is coupled to the third cathode and the first cathode. 6. The high-side driving circuit as claimed in claim 5, wherein the voltage source charges the bootstrap capacitor when the high-side transistor is turned off and the low-side transistor is turned on.

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