BQ27441-G1: BIN thermistor function the same as BQ27426

Luke Mills29

Part Number: BQ27441-G1
Other Parts Discussed in Thread: BQ27426

Hi,

Im looking at using the BQ27441 instead of the BQ27426 in a design.

What I am not clear on is the BIN pin. they have the exact same pin description and it looks like the same function but it is not explicitly stated in the BW27441 datasheet.

The battery thermistor is being used by the charge IC and I want to connect an external thermistor to the BIN pin. The BQ27426 clearly states in section 8.2.3 that it supports an external thermistor, the BQ27441 makes no mention of it.

I believe that they will function the same, the parts are in the same family and have the exact same description on the datasheets and in the reference guide, but I would like someone to confirm this.

Thanks,

Luke

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

Luke,

They are not the same IC but the functionality does support an external thermistor. Check evm schematic here to see the example of implementation, www.ti.com/.../BQ27741-G1

0 Luke Mills29 over 6 years ago in reply to Batt

Prodigy 125 points

Hi Batt,

Thanks, but did you purposely send me the link for the 27741 not the 27441?

Im not sure if it was just a scramble of the digits or if it was purposeful.

Thanks,

Luke

0 Batt over 6 years ago in reply to Luke Mills29

TI__Mastermind 42535 points

Oh, my apologies. I read your post wrong and thought that you were asking about the 741. Yes, the 441 is similar to the 426. If you're not setting the config as non-removable, BIN is similar to the 426.

0 Luke Mills29 over 6 years ago in reply to Batt

Prodigy 125 points

Hi Batt,

I was just pointed to this thread: e2e.ti.com/.../726470

Where they say that I cant use an external thermistor for sensing the battery temperature, but if thats the case I dont understand what connecting a thermistor to the BIN pin would do in terms of functionality.

Thanks,
Luke

0 Batt over 6 years ago in reply to Luke Mills29

TI__Mastermind 42535 points

Luke,

You make a good point. However, on pg 4 of the DS, the BIN pin also mentions the possible use of a thermistor for a pull down. I think that would be mentioned if the pin does double duty. It is possible that this pin may be muxed as in other gauges. However, that would depend on fw. I will check with fw engineers once they are back in Jan and reply back to you. Do remind me on this thread on Jan 2.

0 Batt over 6 years ago in reply to Batt

TI__Mastermind 42535 points

Luke,

I received a reply from the fw engineers. No, the external thermistor is not supported in this case.

0 Luke Mills29 over 6 years ago in reply to Batt

Prodigy 125 points

Hi Batt,

Thanks for the update. Its unfortunate that it wont work. I've been looking at others in the BQ27XXX series of the same footprint and I'm not able to find anything that has external thermistor support and preprogrammed chemistry profiles.

Are there any components you can suggest? These are the ones I found and the issues I had with them.

27411 - No external thermistor support

27510 - no preprogrammed Chem IDs

27542 - no preprogrammed Chem IDs

Thanks,

Luke

0 Batt over 6 years ago in reply to Luke Mills29

TI__Mastermind 42535 points

You don't need preprogrammed chem IDs. That completely limits your choice of batteries. I would suggest that you go with the 542 or 742 series.

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BQ27441-G1: BIN thermistor function the same as BQ27426