The single LTC6268 and dual LTC6269 FET-input op amps from Linear Technology feature a tiny (3 fA typical) input bias current at 25°C (peaking at 4 pA max over the entire –40°C to 125°C temperature range). Their input characteristics make them a good match for photodiode, photomultiplier and other applications using high impedance, high speed sensors. The low distortion output signal can be used by an A/D converter. A shutdown feature lowers power consumption when an amplifier is not in use.

Key Features:

  • Gain Bandwidth Product: 500 MHz
  • –3dB bandwidth (A = 1): 350 MHz
  • Current noise (100 kHz): 5.5 fA/√Hz
  • Voltage noise (1 MHz): 4.3 nV/√Hz
  • Extremely Low CIN 450 fF
  • Rail-to-Rail output
  • Slew rate: 400 V/μs
  • Supply range: 3.1 V to 5.25 V
  • Quiescent current: 16.5 mA (per amplifier)
  • Harmonic distortion (2 VP-P):
    –100 dB at 1 MHz
    –80 dB at 10 MHz

The devices are available in SO-8, 6-Lead TSOT-23, with the dual version in MS8 or 3 x 3 mm 10-lead DFN outline. The SOIC package includes two unconnected pins which can be used to create an input pin guard ring to protect against board leakage currents. Unit prices start from $2.90 in quantities of 1000.