BQ25570EVM-206: Can VOUT = VBAT ?

Claire Yang

Prodigy 50 points

Part Number: BQ25570EVM-206
Other Parts Discussed in Thread: BQ25570

Hi,

I am using BQ25570 to store energy and power the load later. My questions are,

1. Can VOUT be directly connected to VBAT without the buck converter? Since I don't need a buck conversion.

2. What's the maximum output current of VOUT? Can I use it to drive a motor?

Thanks!

Claire

over 2 years ago

0 Jeff F over 2 years ago

TI__Guru*** 143830 points

Hi Claire,

I do not recommend connecting VBAT to VOUT because the input to the buck converter is connect to VSTOR. If you are not using the buck converter, then connect your load directly to VBAT or VSTOR, not VOUT. The buck converter outputs up to 110mA.

Regards,

Jeff

0 Claire Yang over 2 years ago in reply to Jeff F

Prodigy 50 points

Thanks for answering Jeff!

I want to store energy to to a battery in VBAT, and use the power to load only when it's needed. If I connect the load to VSTOR or VBAT, it will run the load whenever the battery is not empty. Is there ways to enable/disable the output of VSTOR or VBAT?

Thanks!

0 Jeff F over 2 years ago in reply to Claire Yang

TI__Guru*** 143830 points

Hi Claire,

Unfortunately, no. You would need to add a FET between VSTOR or BAT and your load and turn it on and off with host GPIO.

Regards,

Jeff

0 Claire Yang over 2 years ago in reply to Jeff F

Prodigy 50 points

Hi Jeff,

I connected the board to DC Power Supply, VIN = 3V, and I can only get VBAT = 2.38V. I don't have other components in the circuit.

When I used the board for the first time, VBAT = 4.1V with VIN = 3V, and VBAT was always ~4.1V was expected.

Why does VBAT become 2.38V? The regulated voltage is incorrect with other input.

Thank you very much!

Claire

0 Jeff F over 2 years ago in reply to Claire Yang

TI__Guru*** 143830 points

Hi Clarie,

Is the boost converter switching? Can you send a scope plot showing VIN_DC, LBOOST an d VSTOR like below?

Regards,

Jeff

Power management

Power management forum

BQ25570EVM-206: Can VOUT = VBAT ?