A fast-settling op amp with low supply current

A dual-operational amplifier that will settle to 0.01% in 400 ns with a 10-V output step is discussed. Quiescent operating current is 3 mA per amplifier. A low-cost, 40-V, bipolar process with junction isolation and complementary transistors having f/sub T/ approximately 150 MHz is used. The design obtains inherent DC accuracy by using an undergenerated bipolar input stage operated with 20- mu A collector currents.<
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