Patent ID: 11863167
Assignee: NANJING GREENCHIP SEMICONDUCTOR CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 8:
9. The drive circuitry of claim 8, wherein said second comparison circuit inputs and compares said voltage of said power supply with said threshold voltage, when said external control signal is at a high level and said voltage of said power supply is higher than said threshold voltage, said two-to-one selection circuit selects and outputs said first control signal to turn off said second pull-up drive transistor, said external power switching transistor is charged by said first pull-up drive transistor; when said voltage of said power supply is lower than said threshold voltage, said on or off state of said second pull-up drive transistor is determined by comparing said output gate voltage of said external power switching transistor with said first reference voltage and said second reference voltage through said first comparison circuit; if said output gate voltage of said external power switch transistor is lower than said first reference voltage, a high-level control signal is outputted from said the two-to-one selection circuit to turn off said second pull-up drive transistor, said external power switching transistor is charged by said first pull-up drive transistor; if said output gate voltage of said external power switching transistor is between said first reference voltage and said second reference voltage, a low-level control signal is outputted through said two-to-one selection circuit to turn on said second pull-up driver transistor, said external power switching transistor is charged by said first pull-up driver transistor and said second pull-up driver transistor; if said output gate voltage of said external power switching transistor is higher than said second reference voltage, a high-level control signal is outputted from said two-to-one selection circuit to turn off said second pull-up drive transistor, said external power switching transistor is charged by said first pull-up driver transistor, wherein said first reference voltage is less than said second reference voltage;
when said external control signal is at low level, both said first pull-up drive transistor and said second pull-up drive transistor are turned off, said first pull-down drive transistor is turned on by said second control signal fed into gate of said first pull-down drive transistor, said external power switching transistor is discharged through said first pull-down drive transistor.