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TPS55165-Q1: TPS55165-Q1

Part Number: TPS55165-Q1

Hi Team,

I would like to use TPS55165-Q1 to supply my electronic board with range Voltage 10-36V.

The question is the following:

I undestand that to enable the DC/DC, I have to set  IGN high and to avoid the event shutdown I can set IGN_PWRL immediately after so that in case of shutdown the DC/DC remain active (keep-alive).

The datsheet indicates:

"This function allows an external MCUto keepTPS5516s-Q1device on even after the IGN pin goes low" but whe when you say that the device is on, the devices connect to DC/DC can be supplied?

In particular, the Output Current can be supplied? If yes, whit is the  value of current guaranteed?

In Low-Power the max current is 50mA so I ask if also in this condition can be a value minimum of output current.

If I set power-latch function (IGN_PWRL high) is there an advantage in terms of minimum chip absorption compared to Low-Power Mode?

I think if there wasn't an advantage in terms of energy optimization in terms of absorbed current compared to Low-Power,I don't understand why you should use the function of power-latch-function.

Or another interpretation would be: in the event of Shutdown of power Supply , the device relmain active being able however to supply current at the output (as a kind of back-up command).

But in this case the function is more usufueI only shutdown event (temporary) because the device cannot remain active if Power Supply was inactive for some time.

I apologize if I overlooked any details in case I would like to fully understand.

Please,let me Know.Thanks.

Best Regards.



  • Hello Davide,

    The expert on this device is out of the office at the moment, so I can only answer based on the information in the datasheet.

    As long as IGN_PWRL is high and the VREG is above it's UV level, the device is able to deliver the full current.

    The lowest power mode is when PS is high, not when IGN_PWRL is high, so no, no advantage compared to low power mode.

    The power latch function can be used for example if in the system a voltage that is different from the supply of the MCU needs to be at a certain level for starting the device. E.g. it might be possible that the MCU has not started because the output voltage of the TPS55165 supplies the MCU supply. Other scenarios are possible as well.

    Yes, some type of backup function is possible as well or some type of brownout for a short period of time for example.

  • Hi Brigitte,

    Ok.

    Please Confirm me if I understand correctly:
    
    if you have two different power supplies i.e. one for the MCU and another power supply for TPS55165 which in turn powers other circuits
    then the power-latch function would be useful as the MCU would directly enable the TPS55165 to supply power to other devices.
    If instead, as in my case, the MCU was powered directly by the TPS55165 (the latter with the input connected to Vbatt)
    it would not make much sense since there are no advantages over low consumption.
    In this case, I connect the IGN at Vcc and IGN_PWRL at GND so the device turn-on as soon as Vbatt is present.
    Then I set the PS high to reduce the consumption.

    It's correct as a concept?
    Please,let me Know.Thanks.
    
    
    
    
  • Hello Davide,

    Yes, this is correct.