Push-Pull Output on BAT_GD on a bq27505-j5

Elizabeth Russell

Other Parts Discussed in Thread: BQ27505-J5

The data sheet for the bq27505-j5 indicates that the BAT_GD pin is a push-pull configuration. However, I am measuring only a high output of 0.9V. I was planning to connect the BAT_GD output to the CE input pin on a 24074 to control charging. The CE input has an internal pull down and the only way I can get this configuration to work properly is to add a pullup to the BAT_GD pin. Is there a problem with doing this or is there a better way to control charging on the 24074 with the bq27505-j5?

Thanks,

Elizabeth

over 9 years ago

0 Jared Casey over 9 years ago

TI__Expert 4115 points

Hello Elizabeth,

Yes, you can add a pull-up to the BAT_GD pin. The pins in the device listed as push-pull can be tri-stated, but since they are not truly open-drain make sure the pull-up voltage is not greater than the gauge's supply voltage (VCC).

I hope this helps.

0 Elizabeth Russell over 9 years ago in reply to Jared Casey

Prodigy 220 points

Thank you for your reply. I didn't see any reference in the data sheet that the BAT_GD pin could be tri-stated. Having the pin described as push-pull gave me the impression that I didn't need the pull-up, but I will add it.

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Push-Pull Output on BAT_GD on a bq27505-j5