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Please introduce the LDOs which can be shutdown by floated EN pin

S.Satoshi
Guru 21685 points
Other Parts Discussed in Thread: TPS7A47

Hi Team,

Now our customer is looking for the LDOs which can be shutdown by floated EN pin. Please let me know if you have some devices which has such function.

Target spec and application

Application : Portable device

Input source : Li-Ion 1s1p

Output voltage : 1.8V, 1.5V, 1.2V (Both adjustable and fixed should be OK)

Output current : 200mA max, but please introduce any devices without regard Iout

 

Background

They shutdown the LDOs by pulling down EN pin by controlling from MCU basically. But they hope to maintain the shutdown if the MCU will be hung-up and the control signal to EN pin will be Hi-Z. This is the reason they are looking for the LDOs which can be shutdown by floated EN pin.

 

I'll let you know the concrete customer and business information if you will contact me directly.

 

 

Best Regards,

Sonoki / Japan Disty

  • 0
    TI__Guru 55940 points

    Sonoki-san,

    An approach that you could take is to add a resistor to ground on the EN pin.  This pull-down resistor will need to be overcome in order to enable the LDO, but it will disable the LDO when you are no longer actively enabling the device.

    Very Respectfully,

    Ryan

  • 0 in reply to Ryan Eslinger
    Guru 21685 points

    Hi Ryan-san,

    Thank you for your response. I know that the external pull-down resister will disable it when the output from MCU is Hi-Z. But they hope to remove this resister because this is space limited portable application. I believe that we can remove it if the EN pin has weak pull-down internally. So we are looking for such LDOs.

    Best Regards,

    Sonoki

  • 0 in reply to S.Satoshi
    TI__Guru 55940 points

    Hi Sonoki-san,

    TPS7A47 is the only device that I know of that functions in this way.

    Very Respectfully,

    Ryan

  • 0 in reply to Ryan Eslinger
    Guru 21685 points

    Hi Ryan-san,

    Thank you for introducing TPS7A47 series. I confirmed the datasheet but I could not find that it has weak pull-down at EN pin because EN pin is not included in block diagram. Anyway I understand that TPS7A47 series has it. I will show our customer this device for their information though it will not be fit for their needs because the target application is portable application in consumer application...

    Best Regards,

    Sonoki