BQ25756: Leakage from SRN/SRP to Vac

Sébastien Lagacé

Part Number: BQ25756
Other Parts Discussed in Thread: TPS25751

Tool/software:

Hello,

I'm measuring my sleep current and i see that the consumption is higher than expected.

There is a voltage on Vac (1.2V) Removing SRn and SRP resistors to the sense. Reduce this voltage to almost 0V and solve my sleep consumption issue.

Is there something to do to solve this? Consumption is around 300uA on a 7.6V battery.

Thank you.

9 months ago

0 Ethan Galloway 9 months ago

TI__Mastermind 31305 points

Hello Sébastien,

I've got a few questions to help troubleshoot this:

What's the voltage of SRN and SRP to GND here?
If you set EN_HIZ=1, does that improve the sleep current?
Can you send me the register settings?

Best Regards,
Ethan Galloway

0 Sébastien Lagacé 9 months ago in reply to Ethan Galloway

Prodigy 155 points

SRP/SRN voltage is 7.6V. I'll try EN_HIZ to see if it helps. For the registers i don't have access to it right now but the charger is controlled via the USB PD IC TPS25751 so most of the registers are by default and we only control sinksource start/stop volt/current.

0 Ethan Galloway 9 months ago in reply to Sébastien Lagacé

TI__Mastermind 31305 points

Hello Sébastien,

I see. Thanks for letting me know about USB PD controller. Do you see any switching on the SW1 and SW2 waveforms?

Best Regards,
Ethan Galloway

0 Sébastien Lagacé 9 months ago in reply to Ethan Galloway

Prodigy 155 points

I tried setting the Hiz and there is no improvements. Regn voltage is down and no switching occurs.

Here's my configuration if you see something.

0 Ethan Galloway 9 months ago in reply to Sébastien Lagacé

TI__Mastermind 31305 points

Hello Sébastien,

Thanks for the information. I don't see anything directly wrong with the circuit.

Do you know where the 1.2V on VAC is coming from?

Best Regards,
Ethan Galloway

Power management

Power management forum

BQ25756: Leakage from SRN/SRP to Vac