Need to identify this TI part

Mike Ciholas

Prodigy 170 points

Other Parts Discussed in Thread: TAS5731

Need help identifying this TI part:

PQFP 44 pin package, appears to be a driver for a gas discharge display.

Searching on 98A7, 98A7JDJ, etc, yields no results.

Likely made around 2007 or so.

Any ideas?

over 2 years ago

0 Clemens Ladisch over 2 years ago

Guru 317370 points

If ti.com/packaging/docs/partlookup.tsp does not find it, then it's likely to be a customer-specific part without public specifications.

0 LeonardEllis over 2 years ago

TI__Guru 71526 points

Hello Mike,

An initial search has come up empty, I will do some do some additional research to see what I can find. I will provide a response by Friday this week.

Regards,

~Leonard

0 LeonardEllis over 2 years ago in reply to Clemens Ladisch

TI__Guru 71526 points

Hello Mike,

Still no results for this device. At first I thought it might be TAS5731, but the pin count does not match.

I will continue to research, but at this point it is probably a custom device, therefore, no information would be provided.

Wondering if you have asked the product/pcb manufacturer for a schematic?

Also, what is the end result of determining the device?

Regards,

~Leonard

0 Mike Ciholas over 2 years ago in reply to LeonardEllis

Prodigy 170 points

The chip is used to drive a gas discharge display used to display engine parameters on an aircraft. The volume of manufacture would be too small, a few thousand at most total production, to justify a custom silicon device for a seemingly simple operation. So I seriously doubt the part is custom made for this unit. I'm trying to ID the part to repair the indicator since it is obsolete and the original maker no longer offers repair services. I can't get schematics. or BOM info.

0 Clemens Ladisch over 2 years ago in reply to Mike Ciholas

Guru 317370 points

It's likely to be an existing part with custom marking.

Identifying it would require knowing what the individual pins are used for.

0 Alexander Mazany over 2 years ago in reply to Clemens Ladisch

TI__Genius 11770 points

Hi Mike,

I am on the gate drivers team. We have some similar-ish parts in the TPICxxx family that are multichannel drivers. However, they are all in SOIC type packages and none have 44 pins. Also, they are from the late 90's.

The only active part I can see on TI.com in a 44-pin QFP package is TL28L92. It released in 2008, which seems to align with the date you listed. Another option is MSP430FR5731.

I understand you don't have the schematic, but maybe you can follow the traces and see what they are connecting to? That should help a lot. Also, if you could confirm exactly which of the 44-pin QFP packages it is, that could help us search. Can you confirm if there is a thermal pad and the height of the package?

Thanks,

Alex M.

0 LeonardEllis over 2 years ago in reply to Alexander Mazany

TI__Guru 71526 points

Hi Mike,

One more idea on the traces . . . see how many traces are connected to the display from the 5731. This may help determine if it is a serial bus that controls the display, or a parallel bus controlling segments.

Also, do you have the part number and manufacturer of the display? If so, they may have some suggested interface designs for controlling the display, with perhaps this device as one of them.

~Leonard