BQ78PL116 Measuring currents over 110 amps

MARK SULLIVAN

Other Parts Discussed in Thread: BQ78PL116, BQWIZARD

I am considering the BQ78PL116 / BQ78PL102 for a LiPo application. I need to support discharge currents in excess of the 110 amps I see in the documentation. Is there some reaon I cannot set IPScale to 2 or 3? Alternatively, assuming the only code talking to the device will be my own, can't I just scale down the sense resistor and treat all current and energy measurements made by the '116 as being scaled up by the same factor?

over 13 years ago

0 ThomasCosby over 13 years ago

TI__Guru 73830 points

Mark,

The IPScale is fixed at 1 or 10 and it only affects data reported over the SMBus interface. You can change the sense resistor setup in the tmap utility under the PackConfiguratioTool in bqWizard. it can be setup to support up to 325A with data reported at 1/10 that value.

Regards

Tom

0 MARK SULLIVAN over 13 years ago in reply to ThomasCosby

Prodigy 100 points

Thanks, Tom,

Actually, I am looking at 1,000 amps.

I guess what I don't understand is why the chip cares at all about the actual scale of the current. If I can set the tmap to 325 amps, why can't I set it to 325 amps, scale the sense resistor by another factor of 10, and assume that SMbus data is scaled by 100?

0 ThomasCosby over 13 years ago in reply to MARK SULLIVAN

TI__Guru 73830 points

Mark,

You can setup the resistor and Hardware Gain to support 1000A, but data reported over the SMBus interface will have to be scaled. I think that this is what you are planning to do.

Tom

0 MARK SULLIVAN over 13 years ago in reply to ThomasCosby

Prodigy 100 points

Yes, that's the idea. Thanks for your help!

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BQ78PL116 Measuring currents over 110 amps