The OP490 is a high-performance micropower quad op amp that operates from a single supply of 1.6 V to 36 V or from dual supplies of 0.8 V to 18 V. Input voltage range includes the negative rail allowing the OP490 to accommodate input signals down to ground in single-supply operation. The OP490's output swing also includes ground when operating from a single supply, enabling "zero-in, zero-out" operation. The quad OP490 draws less than 20 mA of quiescent supply current per amplifier, but each amplifier is able to deliver over 5 mA of output current to a load. Input offset voltage is under 0.5 mV with offset drift below 5 mV/C over the military temperature range. Gain exceeds over 700,000 and CMR is better than 100 dB. A PSRR of under 5.6 mV/V minimizes offset voltage changes experienced in battery-powered systems.