Op amp combining precision, high speed, and high output current drive for ±5-V power supply operation

A monolithic operational amplifier designed for ±5-V power supply operation is described. Precision DC performance includes 100-million V/V open-loop gain, ±25-μV maximum input offset voltage, ±40-nA maximum input bias current, and 2.4-nV/√Hz (at 1 kHz) input voltage noise. AC performance includes 9-V/μs slew rate, 17-MHz bandwidth, and 1-μs settling time to 0.1%; all are measured at unity gain. The op amp is capable of directly driving into a 50-Ω load with up to ±80 mA of output drive current. A novel input bias current cancellation circuit achieves the low input bias current while maintaining a ±3.5-V minimum common-mode input voltage range. A novel output short-circuit protection circuit was developed. It provides good current limiting while allowing an output voltage swing of ±4 V. A novel input offset voltage trimming scheme using laser link cutting is introduced which consumes minimum die area while providing a ±10-μV trim solution (±3-mV trimming range) and excellent long-term stability