BQ2961: BQ2961 - Looking for design review

Daniel Kampert

Part Number: BQ2961

Hi,

I have designed a battery protection circuit for two LiPo cells and I want to ask if this circuit is fine or if there are some issues with this design.

The circuit should be optimized for low power. So I use 1 MOhms resistors for the pull-up / pull-down resistors.

Are there any issues with this circuit?

over 2 years ago

+1 WM5295 over 2 years ago

TI__Guru 54715 points

Hi Daniel,

The BQ2961 should have a capacitor on the REG output at all times. The 5 ohm resistor should be used in series if VSS is not connected first as described in the data sheet https://www.ti.com/document-viewer/BQ2961/datasheet/GUID-25807BB2-BB0C-40C0-905A-C9487FD79A68#TITLE-SLUSBU5SLUSBS87609 design procedure step 1. The capacitor is required for stability of the REG output, so it should not be switched off.

I can't tell the type of Q201, but if positioned after the REG filter capacitor and it works at the desired voltage range it seems the circuit should work. Always test thoroughly.

0 Daniel Kampert over 2 years ago in reply to WM5295

Prodigy 30 points

Hi,

okay I will fix that. Q201 is a SI2301CDS-T1-E3 P-Channel MOSFET. I also change the value of the 5 ohms resistor to 6.8 ohms (it´s easier to source). But this should be fine, because the data sheet say between 5 and 10 ohms.

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BQ2961: BQ2961 - Looking for design review