# Need help identifying an IC

**URL:** <https://forum.digikey.com/t/need-help-identifying-an-ic/58997>\
**Category:** Integrated Circuits (ICs)\
**Tags:** part-identification\
**Created:** [August 18, 2025, 3:08pm UTC](https://forum.digikey.com/t/need-help-identifying-an-ic/58997 "2025-08-18T15:08:55Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![curtissg](https://avatars.discourse-cdn.com/v4/letter/c/8491ac/32.png) [@curtissg](https://forum.digikey.com/u/curtissg)\
**Post date:** [August 18, 2025, 3:08pm UTC](https://forum.digikey.com/t/need-help-identifying-an-ic/58997/1 "2025-08-18T15:08:55Z")

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I have an 18 pin chip with no markings on the top. I pulled it from the PCB and the following letters / numbers are on the bottom:

JZJK A1903HA8

This is part of a fan control circuit. This chip is attached to a series of switches, then in turn, is connected to the inputs of a ULN2003A. The ULN2003A outputs are tied to a series of relays which are connected to various windings of the fan motor.

Ideas?

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**Author:** ![David\_1768](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/david_1768/32/9762_2.png) [@David\_1768](https://forum.digikey.com/u/David_1768)\
**Post date:** [August 18, 2025, 3:22pm UTC](https://forum.digikey.com/t/need-help-identifying-an-ic/58997/2 "2025-08-18T15:22:08Z")

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Hello curtissg,

Sounds like some type of motor control IC chip, but I have no idea what may replace it.

Maybe one of the engineers can add to this post, with some recommendations.

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**Author:** ![curtissg](https://avatars.discourse-cdn.com/v4/letter/c/8491ac/32.png) [@curtissg](https://forum.digikey.com/u/curtissg)\
**Post date:** [August 18, 2025, 3:35pm UTC](https://forum.digikey.com/t/need-help-identifying-an-ic/58997/3 "2025-08-18T15:35:21Z")

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Thanks for checking it out!

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**Author:** ![rick\_1976](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/rick_1976/32/1571_2.png) [@rick\_1976](https://forum.digikey.com/u/rick_1976)\
**Post date:** [August 18, 2025, 5:03pm UTC](https://forum.digikey.com/t/need-help-identifying-an-ic/58997/4 "2025-08-18T17:03:11Z")

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> [@curtissg](#):
>
> This is part of a fan control circuit. This chip is attached to a series of switches, then in turn, is connected to the inputs of a ULN2003A. The ULN2003A outputs are tied to a series of relays which are connected to various windings of the fan motor.

Seems likely as not to be a microcontroller of some flavor, in which case simply replacing the device wouldn’t do much good without the accompanying firmware to program onto it.