Winner, Name that Ware December 2013

The Ware for last December 2013 is the beloved 555 timer, specifically the TLC555 by TI, fabricated in their “LinCMOS” process. I was very excited when T. Holman allowed me to post this as a ware, partially because I love die shots, and partially because the 555 is such a noteworthy chip and up until now I had never seen the inside of one.

The huge transistor on the top left is the discharge N-FET, and the distinctive, round FETs are I believe what makes LinCMOS special. These are tailor-designed transistors for good matching across process conditions, and they form the front ends of the two differential comparators that are the backbone of the threshold/trigger circuit inside the 555.

Picking a winner this time was tough — many close guesses. I’m going to name “eric” the winner, as he not only properly identified the chip, but also gave extensive analysis in his answer as well. DavidG had a correct guess very early on, but no explanation. Jonathan had the right answer, but the divider underneath the big transistor wasn’t done with resistors, it’s done with FETs, and steveM2 also was very, very close but called it a TLC551Y. So congrats to eric, email me to claim your prize.

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