• Resolved

UCC21520: Voltage between VSSB and GND

Part Number: UCC21520


what is the maximum allowed voltage between the pins VSSB and GND. I couldn´t find anything in the datasheet.

I´m interested in this information because I want to use a shunt connected between low side mosfet and PGND.

Thanks for your answer.

  • Hello Philipp,

    I am an applications engineer supporting UCC21520. The VSSB pin (and the whole output channel) is isolated from GND pin and the input side through reinforced capacitive isolation, so the maximum allowed voltage between them is specified in the insulation specifications table of section 6.6 in the datasheet. For example, the DC maximum working voltage between VSSB and GND is listed as 2121V.

    You should have no trouble inserting a shunt between the low side MOSFET and PGND, from an isolation standpoint. If the VDDB power supply is referenced to PGND, be careful to ensure that the rising voltage at VSSB does not cause supply voltage instability. Alternately, consider using an isolated or floating supply, with the common connection directly connected to VSSB.


    Derek Payne

    Texas Instruments