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TPS543320: Enable voltages

Henrik Nielsen
Prodigy 140 points
Part Number: TPS543320

Hi TI.

We are using a voltage divider from Vin to GND to control the Enable pin, and has calculated values to stop at 9.25V (Nom) and start at 10.1V (nom).

The start value is quite precise but the device doesn't stop until Vin is at 6.9V. 

In the datasheet equation 1 and 2 calculates the resistors to be used. We did not use this, be relied on the Ven values. This has given us R_top=200k and R_bottom =27k

I wanted to recalculate using equation 1 and 2, but the equations mentions two costant current sources Ip and Ih, but the values for them are not given anywhere in the schematic.

Can you help with this?

BR Henrik Buhl

  • +1
    TI__Expert 7320 points

    Hi Henrik,

    You can find the Ip and Ih value here in the EC table.

    Ip=1.5uA(typ) and Ih+Ip=11.6uA(typ).

    Also you can use the calculator for TPS543320 on ti.com for easy calculation.

    For 9.25V Vstop and 10.1V Vstart, you can calculate the EN divider resistor as below. Rtop=0.81k and Rbot=0.11k.

    For R_top=200k and R_bottom =27k, you can calculate the Vstop is indeed 6.9V as your test.

    Thank you for your reaching out. The Ip and Ih should be labeled more clear in the datasheet.

  • 0 in reply to Athos Zhao
    Prodigy 140 points

    Hi Athos.

    Thanks for fast reply. I was really helpful.

    Thanks

    Henrik