The dual LT1490 and quad LT1491 op amps operate on all single and split supplies with a total voltage of 2V to 44V drawing only 40µA of quiescent current per amplifier. These amplifiers are reverse supply protected; they draw no current for reverse supply up to 18V. The input range of the LT1490/LT1491 includes both supplies and the output swings to both supplies. Unlike most micropower op amps, the LT1490/LT1491 can drive heavy loads; their rail-to-rail outputs drive 20mA. The LT1490/LT1491 are unity-gain stable and drive all capacitive loads up to 10,000pF when optional 0.22µF and 150Ω compensation is used.The LT1490/LT1491 have a unique input stage that operates and remains high impedance when above the positive supply. The inputs take 44V both differential and common mode even when operating on a 3V supply. Built-in resistors protect the inputs for faults below the negative supply up to 22V. There is no phase reversal of the output for inputs 22V below V–or 44V above V–, independent of V+.The LT1490 dual op amp is available in the 8-pin MSOP, SO and PDIP packages. The quad LT1491 is available in the 14-pin SO and PDIP packages.For new designs it is recommended that the LT1490A/LT1491A be used instead of the LT1490/LT1491. See the LT1490A/LT1491A data sheet for details.ApplicationsBattery- or Solar-Powered SystemsPortable InstrumentationSensor ConditioningSupply Current SensingBattery MonitoringMicropower Active Filters4mA to 20mA Transmitters