Delete comment from: Ken Shirriff's blog

bite said...

@KenShirriff: oh ok right. But you point out another question I always had. Sometimes the N-region (or epitaxial layer) is polarized, in this circuit the whole resistors share the same N-region with Q22 and Q21. What's the purpose of this? For the resistors it's ok, it will reverse bias parasitic diodes but about q22/q21, i have no idea :(
Your book looks like good but a bit expensive :D
My ref. is currently "Bipolar and MOS Analog Circuit Design", it's not bad, I didn't found a better one.

Apr 3, 2016, 11:08:16 AM

Posted to 555 timer teardown: inside the world's most popular IC