TPS65911: PWRDN configuration

K.Hamamoto

Part Number: TPS65911

>The PWRDN input is a reset input with selectable polarity (PWRDN_POL). High(low) level at input forces the TPS65911x device into off mode, causing a power-off reset.

Does it put into Off-mode if PWRDN is low? I do not understand the above explanation ("High(Low) level at input forces the TPS65911x device into off mode")

Is the following my understanding correct?

- High (supplied from VRTC) ; normal (operation) mode

- Low (connected to GND) ; Off mode

Also should we use the pull up resistor when it is connected to VRTC?

Regards,

Koji Hamamoto

over 8 years ago

0 Juha Karttunen over 8 years ago

TI__Intellectual 1120 points

Hi Koji-san,

I will assign your query to TPS65911 expert and we will get back to you.

Regards,
Juha

0 K.Hamamoto over 8 years ago in reply to Juha Karttunen

Guru 12155 points

Hi Juha-san,

Thank you for your support.

In addition, I found the figure at the application note.

http://www.tij.co.jp/jp/lit/ug/swcu181c/swcu181c.pdf

(Figure 1 PWRDN configuration.)

It is mentioned that it should be connected to VRTC if it not used.

As it is mentioned above, I think we should connect PWRDN to VRTC directly if we do not use PWRDN.

Is that correct?

Regards,

Koji Hamamoto

0 Karl Wallinger over 8 years ago in reply to K.Hamamoto

TI__Genius 16410 points

Hi Hamamoto-san,

The polarity of PWRDN depends on PWRDN_POL EEPROM bit. That is why the datasheet says high(low) forced it off, since it depends on the EEPROM bit.

PWRDN_POL=0: PWRDN is active-low, so PWRDN=low will turn off the PMIC, and PWRDN=high will be normal operation.
PWRDN_POL=1: PWRDN is active-high so PWRDN=low will be normal operation, and PWRDN=high will turn off the PMIC.

Regards,
Karl

0 K.Hamamoto over 8 years ago in reply to Karl Wallinger

Guru 12155 points

Hi Karl-san,

Thank you very much for your reply.

I understood about your above answer.

Could you follow the first and second question about the configuration of this pin as well?

Regards,

Koji Hamamoto

0 Nick Jakse49 over 8 years ago in reply to K.Hamamoto

TI__Expert 4155 points

Hi Hamamoto-san,

If you are not using the PWRDN pin, and just want the PMIC to stay on do one of the following depending on your EEPROM settings:
PWRDN_POL=0: Connect PWRDN to VRTC.
PWRDN_POL=1: Connect PWRDN to GND.

If you were using the PWRDN pin, then you would want a pull-up resistor so you could change the input from high to low. If you are not using it then you do not need a pull-up resistor.

Thank you,
Nick

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TPS65911: PWRDN configuration