The nonlinear response of Superconducting Quantum Interference Devices (SQUIDs) has limited their usefulness. We describe the SQUID Operational Amplifier, which consists of several stages of SQUIDs with high open-loop current gain. When connected in a negative-feedback configuration by passing some of the output current through a feedback coil connected to the first stage, the response is linearized. An analog of the semiconductor op-amp, the SQUID op-amp can be used in superconducting equivalents of op-amp circuits such as current amplifiers, current-to-voltage converters, and differentiators. We present experimental results with a /spl times/10 current amplifier as well as a 750 /spl Omega/ current-to-voltage amplifier which can couple directly to a room-temperature amplifier without a transformer or a feedback line.
No takes yet. Share an insight, caveat, or question.
Irwin et al. (2001) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: