LT1491A Datasheet

• Low Input Offset Voltage: 500µV Max
• Output Swings to 10mV Max from V^–
• Rail-to-Rail Input and Output
• Micropower: 50µA/Amplifier Max
• Over-The-Top^® Input Common Mode Range Extends 44V Above V^–, Independent of V⁺
• Specified on 3V, 5V and ±15V Supplies
• High Output Current: 20mA
• Output Drives 10,000pF with Output Compensation
• Reverse Battery Protection to 18V
• No Supply Sequencing Problems
• High Voltage Gain: 1500V/mV
• High CMRR: 98dB
• No Phase Reversal
• Gain Bandwidth Product: 200kHz
• Tiny 3mm × 3mm × 0.8mm DFN Package

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

The LT1491A are quad op amps with a low input offset voltage of 500µV max. The LT1491A 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 virtually no current for reverse supply up to 18V. The input range of the LT1491A includes both supplies and the output swings to both supplies. Unlike most micropower op amps, the LT1491A can drive heavy loads; their rail-to-rail outputs drive 20mA. The LT1491A are unity-gain stable and drive all capacitive loads up to 10,000pF when optional 0.22µF and 150Ω compensation is used.

The LT1491A 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 15V. There is no phase reversal of the output for inputs 15V below V^– or 44V above V^–, independent of V⁺.

The quad LT1491A is available in the 14-pin SO, PDIP and 5mm × 3mm × 0.8mm DFN packages.