BQ34Z100: Calibration is out of range

Cherry Zhou

Part Number: BQ34Z100

Hi team,

Here's an issue from the customer may need your help:

1) The LDO output pin has 2.5 V after normal power up. VEN is used to reduce power consumption, but VEN cannot be pulled high after power up. Does this need to be pulled up? There is no pullup resistor in the reference schematic, is it required to configure any register?

2) 4S1R battery pack, 14.4V 2300Ah battery pack. The customer has configured the number of strings to be 4 and the VOLSEL is configured in a high, red box. After the volt divisor is set to 16800, the hardware pulls up 360K and pulls down 20K. The voltage read by the upper computer is 13044mv, and actual value is 14940mv. Click CAL Calibrate, check calibration voltage, and click Calibrate. However, an error is reported that the calibration voltage is out of range.

Could you help check this case? Thanks.

Best Regards,

Cherry

over 3 years ago

0 Wyatt Keller over 3 years ago

TI__Guru** 105590 points

Hello Cherry,

There is an internal pull-up used by the gauge to measure with VEN.

Make sure you use low tolerance resistors, it seems like the error is very large and you may be going over the maximum calibration values.

Sincerely,

Wyatt Keller

0 Cherry Zhou over 3 years ago in reply to Wyatt Keller

TI__Mastermind 22235 points

Hello Wyatt,

Thanks for your help.

They've referenced above schematic, while the actual measured VEN is not high, dose that make sense?

Thanks and regards,

Cherry

0 Wyatt Keller over 3 years ago in reply to Cherry Zhou

TI__Guru** 105590 points

Hello Cherry,

The VEN pin will not have a DC value, it is only active during voltage measurements so save power consumption for the divider circuit. It should have a pulse approximately 1s interval.

Sincerely,

Wyatt Keller

Power management

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BQ34Z100: Calibration is out of range