PREVENTING VOLTAGE PULSE PROPAGATION IN A DISABLED CAPACITIVE FEEDBACK SLEW-CONTROLLED SWITCH

摘要

Transient voltages are not propagated through a P-channel MOSFET used as a switch with output slew rate control feedback, by connecting a low or near-zero impedance across the source and gate terminals of the device whenever the MOSFET is supposed to be off. The low or near-zero impedance is provided by a second P-channel MOSFET connected across the source and gate of the MOSFET switch.

主权项

1. A switching circuit, configured to prevent or at least reduce transient voltage propagation through a semiconductor switch, the output voltage slew rate of which is controlled using capacitive feedback, the switching circuit comprising:
a three-terminal semiconductor switch having a first input terminal, which is configured to be coupled to a voltage source, a first output terminal configured to be coupled to a load, and a first control terminal; a turn off circuit having a second input terminal coupled to the first input terminal, a second output terminal coupled to the first control terminal, and a second control terminal coupled to an on/off terminal for the switching circuit; and a slew rate controlled turn on circuit having a third input terminal coupled to the first output terminal, a third output terminal coupled to the first control terminal, and a third control input terminal coupled to the on/off terminal.