TPS65219: The PB Pin control the power-on

Rannie Zhou

Part Number: TPS65219

Tool/software:

Hi team,

Pin 25 of TPS6521910 is PB by default. When my customer uses TPS6521910, there is no reserved button in the schematic diagram. How can they achieve power-on enable in this case?

BRs,

Rannie

5 months ago

0 Katie Pier 5 months ago

TI__Guru* 77991 points

Thank you for your inquiry. US and Europe TI offices are closed on April 18th. This thread has been assigned but you will receive a response early next week. Thank you for your patience!

Regards,

Katie

0 Sathish Vallamkonda 5 months ago in reply to Katie Pier

TI__Expert 6245 points

Hi Rannie,

Thank you for reaching our on e2e.

You are correct, 10 version of this device is configured for PB, however since FSD (First Supply Detection) is enabled on this device, it will automatically go thru power up routine as soon as VSYS reaches the desired voltage. PB is ignored on the first power up. After that, user will have to use PB to power up the device again.

Sathish

0 Rannie Zhou 5 months ago in reply to Sathish Vallamkonda

TI__Expert 4180 points

Hi Sathish,

Thanks for you confirm.

The first power-on you mentioned refers to the time when our chip is sent from the factory to the customer?
The customer does not have a reserved PB interface. Can the MCU control the pull-down time to achieve power up?

BRs,

Rannie

0 Sathish Vallamkonda 5 months ago in reply to Rannie Zhou

TI__Expert 6245 points

Hi Rannie,

First power up meaning, each time VSYS is going low to high, the device goes thru power up sequence irrespective of EN/PB pin status.

Yes, MCU can pulldown the PB pin to meet the ON and OFF requests.

Let me know if you have any further questions.

Sathish

0 Rannie Zhou 5 months ago in reply to Sathish Vallamkonda

TI__Expert 4180 points

Hi Sathish,

Understood. On the customer's schematic, the EN/PBNSENSE isn't functional. When VSYS rises, the PMIC starts working without needing additional enable controls. If the PMIC freezes or stuck and need restart, the only way to restart it is to restart VSYS. Is that right? If customer design external drive circuit for the PB pin, then they can restart/wake-up the PMIC through external circuit but not Vsys. right?

BRs,

Rannie

0 Sathish Vallamkonda 4 months ago in reply to Rannie Zhou

TI__Expert 6245 points

Hi Rannie,

PB is for initiating the powerup or power down routines of all the output rails.

VSYS is the main power input to the device. With FSD is enabled, device goes thru power up routine each time VSYS goes low to high.

Please look at the device stat diagram on page 51 of, https://www.ti.com/lit/ds/symlink/tps65219.pdf?ts=1745434739673&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS65219

Sathish

0 Rannie Zhou 4 months ago in reply to Sathish Vallamkonda

TI__Expert 4180 points

Hi Sathish,

I noticed that it needs "ON request" from INITIALIZE to ACTIVE. If FSD is enabled, TPS6521910 can enter ACTIVE even if power on Vsys w/o any operation on PB Pin (no ON request), right?

I noticed that in datasheet, the push button is optional not required.

BRs,

Rannie

0 Sathish Vallamkonda 4 months ago in reply to Rannie Zhou

TI__Expert 6245 points

Hi Rannie,

When FSD is enabled, it ignores the EN/PB on the first power up (VSYS going low to high), so it can enter ACTIVE state w/o any operation on PB pin. ON request is an internal signal and that is taken care of internally.

Push button is only needed when you want to power cycle all the rails.

Sathish

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TPS65219: The PB Pin control the power-on