BQ25629EVM: BQ25629: Enabling PMID boost mode when powered via battery

Chamith Koperahewa

Prodigy 40 points

Part Number: BQ25629EVM

We are currently facing problems in enabling boost mode to power up the PMID at 5040mV and enabling PMID output

Current Status

Powered via USB (5V)

PMID_GD - Turns on (4.9V)
PMID - 4.9V
PMID output voltage - 4.9V
EN_OTG set to 1
Vregn > Vregn_ok
Vts is the appropriate region
VOTG is set to 5200mV but PMID voltage is at ~5000mV

Power via battery (~4100mV)

PMID_GD - Turned off (0V)
PMID - 3700mV
PMID output voltage - 0V
EN_OTG set to 1
Vregn > Vregn_ok
Vts is the appropriate region
VOTG is set to 5200mV but PMID votlage is at ~ 3700mV

I am in need of enabling Boost and bypass modes when powered via both modes. Will it be possible for you to provide support on this matter.

Thank you,
Sincerely,
Chamith Koperahewa

5 months ago

0 Garrett Kreger 5 months ago

TI__Mastermind 23655 points

Hi Chamith,

Thank you for reaching out via E2E. Please see my comments below.

For case one where you are powered via USB input boost mode operation is not allowed. One of the requirements for boost mode operation is VBUS input is removed. This is stated in section 8.3.6.1 of the datasheet. PMID pin is connected to VBUS through Q1 (RBFET) as shown in the functional block diagram on datasheet page 20. With a 5V input PMID = approx. 4.9V is expected.

For case two do you have a load connected to the PMID output of the EVM? Have you checked if EN_OTG is resetting to 0 after you set it to 1? For boost mode operation I also recommend you disable the watchdog first REG0X16[1:0] = 0h.

Best Regards,

Garrett

Power management

Power management forum

BQ25629EVM: BQ25629: Enabling PMID boost mode when powered via battery