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TPS65910: TPS65910 VRTC PWRON

Mitsuharu Iwasaki7
Intellectual 540 points
Part Number: TPS65910

Hello  all,

I would like to confirm two items about TPS65910 specification.

1st:

TPS65910 datasheet on page 40 shows VRTC rising and VMBHI threshold look like the same timing.

It means VRTC rising time depends on VCC7 rising time. Is it correct?

2nd:

TPS65910 datasheet on page 40 shows tdbPWRONF

When PWRON is used as Device power-on enable condition, Low level is forced to PWRON pin initially and High level is forced to it lately.

How long time is needed to be kept high level for PWRON pin as Device power-on enable condition?

Best Regards.,

Mitsuharu Iwasaki

 

  • 0
    TI__Mastermind 30260 points

    Iwasaki-san,

    It would be helpful to know which processor you are powering with the TPS65910, but for now I will assume it is the Sitara AM335x.

    Mitsuharu Iwasaki7 said:

    1st:

    TPS65910 datasheet on page 40 shows VRTC rising and VMBHI threshold look like the same timing.

    It means VRTC rising time depends on VCC7 rising time. Is it correct?

    Yes, VRTC is turned on immediately, as soon as VCC7 is applied.

    Mitsuharu Iwasaki7 said:

    2nd:

    TPS65910 datasheet on page 40 shows tdbPWRONF

    When PWRON is used as Device power-on enable condition, Low level is forced to PWRON pin initially and High level is forced to it lately.

    How long time is needed to be kept high level for PWRON pin as Device power-on enable condition?

    PWRON is supposed to be connected to a push-button. The signal has a debounce delay of 500-550ms, as shown on page 41 of the datasheet. The PWRON pin must be high again in <8s, or it will count as a long-press and turn-off the system (tdPWRONLPTO). It does not matter how long PWRON is high. It can be high forever and nothing will happen. Only low time matters.

  • 0 in reply to Brian Berner
    TI__Mastermind 30260 points

    Iwasaki-san,

    As a follow-up, the TPS65910Ax devices for AM335x do not require a push-button press to start the power-on sequence (BOOT1 = VRTC, BOOT0 = GND).

    When BOOT[1:0] = 00b, 01b the device follows the TPS65910 datasheet and a push-button press will be required to start the system.