A high-voltage and high-current control circuit used in a high-voltage power mosfet circuit

Abstract

A high-voltage high-current control circuit applied to a high-voltage power MOSFET (metal-oxide-semiconductor field effect transistor) circuit comprises a PMOS (P-channel metal oxide semiconductor) tube MP1, a PMOS tube MP2, a PMOS tube MP3, a triode Q1, a triode Q2, an MOSFET tube M1, an MOSFET tube M2, a resistor R1 and a resistor R2, wherein the MP1, the MP2 and the MP3 share a grid electrode; the source electrodes of the MP1, the MP2 and the MP3 are connected with a VDD; the drain electrodes of the MP2 and the MP3 are connected with the collector electrodes of the Q1 and the Q2 respectively; the base electrodes of the Q1 and the Q2 are connected with each other; the emitting electrodes of the Q1 and the Q2 are connected with the R1 and the R2 respectively; the M1 and the M2 share a grid electrode and share a drain electrode; the source electrode of the M1 is connected with the R1; the source electrode of the M2, the R1 and the R2 are grounded; the Q1 is matched with the Q2; the R1 and the R2 are resistors matched with each other according to a proportional relation; the width-to-length ratio of the M1 is proportional to that of the M2. The high-voltage high-current control circuit does not consider a channel length modulation effect of a transistor, introduces a negative feedback by the R1 and converts high current into a current comparison signal, thus achieving precise control over the current in a high-voltage high-current mode.

Description

technical field [0001] The invention relates to a current control circuit for high-voltage power MOSFET, in particular to a high-voltage and high-current control circuit for accurately setting a current reference of a common MOS tube and converting it into a high-voltage power MOSFET circuit. Background technique [0002] figure 1 is a known current source mirror circuit, mirroring the reference current I ref It is generated by the current reference source of the low temperature coefficient module, namely BIAS. MP1 and MP2 are ordinary PMOS tubes, and MN1 and MN2 are ordinary NMOS tubes. The drain current I flowing through the NMOS transistor MN1 D1 and the drain current I flowing through the NMOS transistor MN2 D2 They are: [0003] I D 1 = 1 2 u n c o x ...

AI Technical Summary

Problems solved by technology

[0008] However, with the wide application of high-voltage power MOSFETs, the current setting in high-voltage power MOSFETs has become a new problem in DMOS process design

On the one hand, with the improvement of the process, the channel length of the power MOSFET is shorter, resulting in a more serious channel length modulation effect

On the other hand, the drain voltage of the power MOSFET tube is high, and the voltage variation range is large, which further reduces the current mirroring accuracy of the MOS tube.

The existing current mirror structure is no longer widely applicable to the current control of power MOSFETs under high voltage conditions

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