Bootstrap structure and bootstrap circuit integrated on high and low voltage isolation structure

Abstract

The invention relates to a bootstrap structure integrated to a high-and-low-voltage isolation structure and a bootstrap circuit. The bootstrap structure is composed of a first doped type substrate serving as a substrate for a high-and-low-voltage isolation structure, a second doped type drift region serving as a drift region, and a first doped type substrate contact well serving as a substrate contact well. A first doped type substrate contact region as a substrate contact electrode is arranged in the first doped type contact well. A bootstrap structure positive electrode and a bootstrap structure negative electrode are respectively provided in the second doped type drift region; the bootstrap structure positive electrode is one second doped type contact region arranged in the second dopedtype drift region; the bootstrap structure negative electrode is the other second doped type contact region arranged in the second doped type drift region; and the bootstrap structure positive electrode is adjacent to the first doped type contact region. In addition, the bootstrap circuit consists of a bootstrap structure and a bootstrap capacitor; a diode is connected to the bootstrap structurepositive electrode; and the bootstrap capacitor is connected with the bootstrap structure negative electrode.

Description

technical field [0001] The invention relates to a high-voltage half-bridge drive circuit in a high-voltage power integrated circuit, in particular to a bootstrap structure and bootstrap circuit technology integrated on a high-voltage and low-voltage isolation structure, and belongs to the field of power semiconductor drive technology. Background technique [0002] The high-voltage half-bridge drive circuit can be used in various fields, such as motor drive, electronic ballast, switching power supply and other fields. It is used to drive two power switching devices connected in the form of totem poles to make them alternately conduct Pass. The typical connection method of the half-bridge driver chip without integrated bootstrap diode is as follows: figure 2 As shown, among them, VCC is the low-side fixed power supply, HIN and LIN are the high-side input signal and low-side input signal respectively, COM is the ground signal, VB is the high-side floating power supply, HO and ...

AI Technical Summary

Problems solved by technology

However, (1) the use of external bootstrap diodes increases the additional cost of system applications, and also increases the difficulty of system layout and wiring and the size of the system

(2) The external bootstrap diode is a high-voltage diode, and its reverse recovery charge Qrr is large. During the reverse recovery process, the charge on the bootstrap capacitor will be taken away, making the high-side power supply insufficient

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