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TPS65070: power on fail

Part Number: TPS65070

I'm using the TPS65070 as Power-Manager of an IIoT-System.
As power-supply I use LiPo or/and AC. After booting the TSP EN_DCDC1 is high and in the CON_CTRL1-Register there is the default setting “01111111”
This means after pulling down PB_IN the DCDC1-Converter should start when EN_DCDC1 is high. (While pulling down PB_IN, POWER_ON is set high)
The first time after attaching a power supply the TCP boots properly and the DCDC1 supplies the configured voltage.
After shutting down with pulling POWER_ON to low a reboot of the TPS doesn't start the DCDC1.

How can I fix this problem?

Yours sincerely,

  • Hi Kamal,

    The device expert for this is out of the office for the holidays, please expect some delay.

    How are you rebooting the TPS65070? To confirm, the sequence is PB_IN pulses low, TPS65070 starts up, POWER_ON is set high by the processor (or pulled up to one of the TPS65070 rails) before PB_IN goes high again within 15 s. Then POWER_ON is set low again to shut the device OFF. When PB_IN is pressed a second time, the device does not start? Are there any I2C writes sent to the TPS65070?

    Thanks,

    Kevin LaRosa

  • Kamal,
    Below is a brief description for the POWER_ON. The TPS will enter POWER_ON 2 state and start the rails according to the programmed sequence.

    Note: if the USB or AC inputs are removed you will have to restart with PB_IN.

    10.3.11.5 POWER_ON
    This pin is an input to the PMU which needs to be pulled HIGH for the PMU to stay in POWER ON_2-state once
    PB_IN is released. Once this pin is pulled LOW while PB_IN=LOW, the PMU is shutting down without delay,
    turning off the DCDC converters and the LDOs. If POWER_ON is pulled HIGH while there is power at USB or
    AC, the TPS6507x will enter POWER ON_2-state and start the DC-DC converters and LDOs according to the
    sequence programmed. See Figure 34.

    If this does not clarify or help your condition, please explain your startup sequence or restart in greater detail so that we may better understand the problem.

    Sincerely,

    Gordon Varney