EDN

Diff-Amp Uses a Resistor Network

Low-cost integrated resistor networks can be used to implement a low-parts-count two-op-amp differential amplifier with low common-mode gain. Integrated onto a common substrate and processed together, ...
EDN

Seemingly Simple Circuits, Part 1: The One-Op-Amp Diff-Amp

The following is Part 1 of a four-part series. The basic one-op-amp differential amplifier consists of one op-amp and four resistors. Yet few have contemplated the depth of its complexity. It is ...
Electronic Design

So…LTspice of the K2-W Op Amp Reveals the Mad Scientists’ Fingerprints (Part 3)

LTspice simulation of the K2-W Vacuum Tube Op Amp’s design reveals the mad science that created a commercial revolution in 1950s and 1960s analog computing. The K2-W's first-stage differencing ...
Electronic Design

So…The First Stage of the K2-W Op Amp is Neither Balanced Nor Differential (Part 2)

Design analysis of the K2-W Vacuum Tube Op Amp’s design and operation reveals the mad science that created a commercial revolution in 1950s and 1960s analog computing. Op amps played a critical role ...