Narrow pulse pull-down current type level displacement circuit

Abstract

The invention belongs to the field of electronic technology and relates to an integrated level displacement circuit, which consists essentially of seven circuit units including input buffer 1, permanent current source switch A and B, pulse self-generating A and B, grid electrode pull-down 6 and phase inverter 7. Through inputting buffer 1, low logic signal IN generates in-phase and anti-phase control signals S1 and S2 used for controlling permanent current source switch A and B to obtain permanent current output signal S3 and S4; obtains narrow pulse pull-down current S5 and S6 through pulse self-generating A and pulse self-generating B circuit; and generates VB-VH floating level displacement signal S7 through grid electrode pull-down 6 circuit. After S7 passes through phase inverter 7, high logic signal Vout-VB that is the same as and synchronous with the low logic signal IN will be generated between the output end of the phase inverter 7 and the high-end floating VB. The invention has advantages of simplicity of circuit, low requirements for the device, low self-consumption of power, mis-triggering avoidance, stable working condition, easiness for integration and suitability for high-pressure application.

Description

technical field [0001] The invention belongs to the field of electronic technology, relates to an integrated level shift circuit, and simultaneously relates to a driving circuit of a floating high-end MOS switch. Background technique [0002] In the intelligent power integrated circuit of the bridge power switch structure, the high-side bridge arm and the low-side bridge arm are composed of power MOS or IGBT. The driving of the high-side bridge arm has the following basic requirements: First, the lower logic level compatible with CMOS / TTL logic needs to be shifted to the high logic level that can drive the power switch. Second, in order to make the working states of the high-side and low-side MOS switches symmetrical, the same logic level as that of the low-side MOS switch must be provided between the gate and source of the high-side MOS switch. However, in the switching process of the high-side bridge arm, the source potential of the power MOS used as a high-side switch fl...

AI Technical Summary

Problems solved by technology

However, since the rising edge and falling edge of the control signal are converted into narrow pulses respectively, the circuit is very complicated

In addition, the logic level on the high side is obtained directly from the voltage across the load resistor R1 or R2, and the displacement current when the power switch is turned on or off can easily generate voltage fluctuations on the load resistors R1 and R2, resulting in false trigger signals

Therefore, a certain pulse filter circuit must be used at the high voltage end to eliminate false trigger signals, which also increases the complexity of the circuit

[0007] To sum up, the currently used level shifting circuit has complex circuits, high device requirements, and is not suitable for high-voltage applications.

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