building an amplifier from transistors is sometimes simpler/cheaper than using an op amp. And some designs don’t need the benefit of op amps.
On the other hand, building a timing circuit from discrete components is less obvious. And the 555 does so much of what often needs doing.
Also, the design was not patented so they were commodity chips right away.
building an amplifier from transistors is sometimes simpler/cheaper than using an op amp. And some designs don’t need the benefit of op amps.
On the other hand, building a timing circuit from discrete components is less obvious. And the 555 does so much of what often needs doing.
Also, the design was not patented so they were commodity chips right away.