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TRS3223-Q1: TRS3223 minus voltage generation of charge pump

Part Number: TRS3223-Q1
Other Parts Discussed in Thread: TRS3223

Dear support team

TRS3223 ESD failure that V- pin breaks down occurs  in my customers.

Could you provide the way of the minus voltage generation of the charge pump?

(Is it only -1 gain charge pump?)

Regards

Tomohiro Nagasawa

  • Tomohiro-san,

    The charge pump works as a voltage doubler. At first cycle, one end of C1 is charged to Vcc while the other end is shorted to gnd. At the second cycle, as the other end is pushed up from gnd to Vcc, C1 will generate a 2Vcc to V+. For the same methology, C2 will generate a -2Vcc from gnd while the other end drops from 2Vcc to gnd. Hope this helps. Please let me know if you other question. You should be able to observe the voltage change on the external capacitors. Thanks,  

  • Hello Hao-san

    Thank you for quick response.

    In the case of vcc=5V, does it mean that -2Vcc=-10V is applied to V- pin?

    (Seeing datasheet, absolute maximum rating of  V- pin is -7V.)

    Is it correct?

    Regards

    Tomohiro Nagasawa

  • Tomohiro-san,

    Theoretically the charge pump is able to double the input voltage. But due to parasitic capacitor and resistor, in reality it cannot achieve 100% efficiency. Therefore about 7V is generated out of 5V supply. Please let me know if you any question. Thanks!