LT1491

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.

Applications

• Battery- or Solar-Powered Systems
  • Portable Instrumentation
  • Sensor Conditioning
• Supply Current Sensing
• Battery Monitoring
• Micropower Active Filters
• 4mA to 20mA Transmitters