What’s All This Varactor-Input Amplifier Stuff, Anyway? (.PDF Download)

    Sept. 9, 2016

    In 2008, Marcello Salvatierra took the picture above of a circuit Bob Pease had just built. Bob told him it was based on a circuit that Jim Williams did in 1967. Despite working for competitors, Bob and Jim were good friends.

    I did not recognize it, so I asked some analog aficionados what it might be. Alan Martin redrew the circuit in Altium, which made its signal paths clearer. Bob Dobkin, CTO of Linear Technology, recognized it immediately. He said, “At a glance, it looks like a varactor input op amp, like the Philbrick P-2”. This makes sense; Pease wrote a chapter about the P2 in Jim Williams’ analog design book...

    Register or Sign in below to download the full article in .PDF format, including high-resolution graphics and schematics when applicable.

    Download

    Continue Reading

    Sponsored

    A microcontroller with an integrated energy harvester offers a way to extend battery life and replacement batteries
    Integrated power supply ICs to implement compact and efficient buck converters for factory automation, 5G and IoT.
    Learn how integrated voltage sensing solutions support a more efficient and affordable way of measuring battery life to increase driving range and charge time.
    Transformers are widely used to efficiently transfer both power and data in switching power supplies, MOSFET gate drivers, and isolation circuits.