TUSB4041, PWRCTR_POL pin

emanuel stiebler

Hi,

I have a design here, where I used power switches with negative polarity. So I connected pins 8(FULLPWRMGTZ) and pin 10(GANGED) via 4k7 pulldowns

to GND, and pin 9 (PWRCTL_POL) via 4k7 pullup to +3v3. However, the chip still uses positive polarity,

and that doesn't even change (same behaviour), when I remove the pullup.

What did I miss?

Thanks

over 9 years ago

0 Elias Villegas M. over 9 years ago

TI__Guru* 76130 points

Hello,
You have to install an external pull-down on terminal PWRCTL_POL for active-low power switches.
Regards

0 emanuel stiebler over 9 years ago in reply to Elias Villegas M.

Prodigy 140 points

Hi Elias,

then the description for the EVAL board is wrong, page 6 states:

SW2_3 (off): PWRCTL_POL_TDO Switch. The TUSB4041 has an internal pulldown on this terminal,
so port power control polarity defaults to active high. If the switch is set to the ON
position, the terminal is pulled high and the port power control polarity changes to active
low.

0 Elias Villegas M. over 9 years ago in reply to emanuel stiebler

TI__Guru* 76130 points

Hello,
Thank you for your comments, it looks like the EVM document is wrong, we are going to fix it, please follow the datasheet.
Regards

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TUSB4041, PWRCTR_POL pin