BQ4802LY: cross-reference compatibility

Chris Schneider

Part Number: BQ4802LY

i'm working on a retro project that requires an older TI based real time clock chip (BQ4847YMT) as it has the need to control external SRAM.

I see that the BQ4802LY has this ability, but doe not have a built in crystal. I am wondering if this chip is compatible for the functionality to replace the BQ4847YMT? I know I will need to build an adapter board to solder the chip and a crystal to if it is.

Can anyone tell me if this RTC will work or is there a better selection from a new active chip for me to use?

The original BQ4847 datasheet is attached.

bq4847.pdf

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 80543 points

Hi Chris,

I do not know anything about the BQ4847 since it has been obsolete for several years and I do not think there are any engineers in TI remaining who are familiar with this device. Therefore I cannot say whether these are functionally compatible.

However, it does appear that you have found the closest available match. The pinout is very similar and you would need to add a crystal. It also looks like the BQ4847 had a battery integrated into the device while the BQ4802LY does not. I think the BQ4802LY is a good selection, but it will require some work to switch over.

Sorry I do not have a more convenient option to offer.

Best regards,

Matt

0 Chris Schneider over 4 years ago in reply to Matt Sunna

Prodigy 130 points

is it possible for me to obtain samples since this is not for a corporate or university for this product?

0 Matt Sunna over 4 years ago in reply to Chris Schneider

TI__Guru* 80543 points

Hi Chris,

I'm sorry, I don't know the details on TI's sample request policies. You can request samples at the site below as far as I know. E2E is only for technical questions, but you can ask TI customer service if you need help with this.

https://tisamples.ti.com/order/tisamples/en/

https://ticsc.service-now.com/csm

Best regards,

Matt

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BQ4802LY: cross-reference compatibility