BQ32002: BQ32002 Crystal oscillator can't start

Yang Wu

Part Number: BQ32002

Hi Team,

My customer uses BQ32002, but the crystal oscillator can't start, even the crystal oscillator is directly connected to BQ32002 without peripheral circuit. A-B-A test has already been tried, but it doesn't work.

So, what are your suggestions?

Thanks!

Yang

over 5 years ago

0 Noel Fung over 5 years ago

TI__Guru* 87520 points

Hi Yang,
Will it works if you remove C232 and C347?

0 Yang Wu over 5 years ago in reply to Noel Fung

TI__Expert 3010 points

Hi Noel,

It doesn't work. I don't know why it has these problem. but customer's all 30 boards failed.

0 Noel Fung over 5 years ago in reply to Yang Wu

TI__Guru* 87520 points

ha, I just spot the error. The layout did not connect the Vcc pin properly, it is an open trace.

0 Yang Wu over 5 years ago in reply to Noel Fung

TI__Expert 3010 points

Hi Noel,

I just called the customer to confirm, some layers were hidden, it was not an open trace.

0 KevinZhang123 over 5 years ago in reply to Yang Wu

TI__Expert 5750 points

Hi, Noel

Here are more information.
1. I2C communication with BQ32002 is correct. Cutomer can read Reg 0x01 and bit 7 is 1. That shows error in oscillator.
2. Customer has tried difference kind of 32.768kHz oscillator. It still doesn't work.
3. Teh voltage on OSCI and OSCO pin is about 0.5V.
Please help to check it.

Thanks
Kevin

0 Noel Fung over 5 years ago in reply to KevinZhang123

TI__Guru* 87520 points

Hi Kevin,

Not sure what happen but good to try the operation as outlined in section 7.6.2 of the datasheet.

Oscillator stop. The STOP bit is used to force the oscillator to stop oscillating. STOP is set to 0 on initial application of
power, on all subsequent power cycles STOP remains unchanged. On initial power application STOP can be written to 1
and then written to 0 to force start the oscillator.

Can they try write a 1 to STOP and then 0 to STOP after Vcc power up?

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BQ32002: BQ32002 Crystal oscillator can't start