LF156 - JFET Input Operational Amplifiers

The LFx5x devices are the first monolithic JFET input operational amplifiers to incorporate well-matched, high-voltage JFETs on the same chip with standard bipolar transistors (BI-FET™ Technology). These amplifiers feature low input bias and offset currents/low offset voltage and offset voltage drift, coupled with offset adjust, which does not degrade drift or common-mode rejection. The devices are also designed for high slew rate, wide bandwidth, extremely fast settling time, low voltage and current noise and a low 1/f noise corner.

• Advantages
  • Replace Expensive Hybrid and Module FET
    Op Amps
  • Rugged JFETs Allow Blow-Out Free Handling
    Compared With MOSFET Input Devices
  • Excellent for Low Noise Applications Using
    Either High or Low Source Impedance–Very
    Low 1/f Corner
  • Offset Adjust Does Not Degrade Drift or
    Common-Mode Rejection as in Most
    Monolithic Amplifiers
  • New Output Stage Allows Use of Large
    Capacitive Loads (5,000 pF) Without Stability
    Problems
  • Internal Compensation and Large Differential
    Input Voltage Capability
• Common Features
  • Low Input Bias Current: 30 pA
  • Low Input Offset Current: 3 pA
  • High Input Impedance: 10¹² Ω
  • Low Input Noise Current: 0.01 pA/√Hz
  • High Common-Mode Rejection Ratio: 100 dB
  • Large DC Voltage Gain: 106 dB
• Uncommon Features
  • Extremely Fast Settling Time to 0.01%:
    • 4 µs for the LFx55 devices
    • 1.5 µs for the LFx56
    • 1.5 µs for the LFx57 (A_V = 5)
  • Fast Slew Rate:
    • 5 V/µs for the LFx55
    • 12 V/µs for the LFx56
    • 50 V/µs for the LFx57 (A_V = 5)
  • Wide Gain Bandwidth:
    • 2.5 MHz for the LFx55 devices
    • 5 MHz for the LFx56
    • 20 MHz for the LFx57 (A_V = 5)
  • Low Input Noise Voltage:
    • 20 nV/√Hz for the LFx55
    • 12 nV/√Hz for the LFx56
    • 12 nV/√Hz for the LFx57 (A_V = 5)