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TPS62745: Higher Input Voltage

Part Number: TPS62745

Hello,

I have a a design using the TPS62745 to convert 6V battery input to 3.3V out.

The TPS62745 works perfectly thanks to its low Quiescent Current and the Input voltage switch allowing to measure battery levels only when powered.

I need to update the design to take 12V input, but the TPS62745 only goes up to 10.

Alternatives seem to hav slightly higher Quiescent Current (which can still work) but none seems to have the input voltage switch. 

What would be the best alternative?

  • Hi Michael,

    Do you mean VIN_SW function of TPS62745?

    We have many low Iq parts supporting 12Vin but we don't have other low Iq parts have this input voltage switch.

    May I know how you use this switch? Maybe we can figure out some other solution for you needs.

  • Hello Athos,

    Thank you for the reply.  yes, the VIN_SW and EN_VIN_SW.

    I have a 3V board powered by 12V batteries. the board goes to sleep and occasionally wakes up for a few seconds to operate. 

    While it's operating, I measure the battery voltage. without the EN_VIN_SW, the voltage measurement will draw power even when the board is asleep. 

    The functionality is described in section 8.3.5 of the datasheet:

    There is an internal switch that connects the input voltage applied at pin VIN to the VIN_SW output. The switch can be used to connect an external voltage divider for an ADC monitoring to the input voltage. An enable pin EN_VIN_SW turns the switch on and off, making sure there is no current through that external voltage divider when not needed. A logic high level on EN_VIN_SW turns the switch on once the input voltage is above the undervoltage lockout threshold and the device is enabled. The switch can be used for other purposes as long as the current rating of 5 mA and its turn-on resistance is observed. An external voltage divider should be in a range of 10 kΩ to 100 kΩ. Larger values than 100 kΩ can be used as long as the input resistance and capacitance of the external circuit (e.g. ADC input) is observed.

  • Hi Michael,

    I'm sorry we don't have devices which could support input voltage switch and 12Vin meanwhile currently.

    Maybe you can use a separate switch for this function.

    If you're interested in developing devices in our roadmap, please contact me via email. athos-zhao@ti.com

  • Thank you Athos, any switch you can recommend for the use case?

  • Hi Michael,

    My colleague will give you feedback next week!

    BRs

    Zixu

  • Hi Michael,

    I think a 20V 0.1A single N-channel MOSFET is ok for this application.