1 Features

• (Maximum Limit, 25°C Unless Otherwise Noted)
• Input Current (100% Tested): 25 fA
• Input Current Over Temperature: 2 pA
• Low Power: 750 μA
• Low V_OS: 350 μV
• Low Noise: 22 nV/√Hz at 1 kHz Typical

2 Applications

• Electrometer Amplifiers
• Photodiode Preamplifiers
• Ion Detectors
• A.T.E. Leakage Testing

3 Description

Featuring 100% tested input currents of 25 fA maximum, low operating power, and ESD protection of 2000 V, the LMC6001 device achieves a new industry benchmark for low input current operational amplifiers. By tightly controlling the molding compound, Texas Instruments is able to offer this ultra-low input current in a lower cost molded package.

To avoid long turnon settling times common in other low input current op amps, the LMC6001A is tested three times in the first minute of operation. Even units that meet the 25-fA limit are rejected if they drift.

Because of the ultra-low input current noise of 0.13 fA/√Hz, the LMC6001 can provide almost noiseless amplification of high resistance signal sources. Adding only 1 dB at 100 kΩ, 0.1 dB at 1 MΩ and 0.01 dB or less from 10 MΩ to 2,000 MΩ, the LMC6001 is an almost noiseless amplifier.

The LMC6001 is ideally suited for electrometer applications requiring ultra-low input leakage such as sensitive photodetection transimpedance amplifiers and sensor amplifiers. Because input referred noise is only 22 nV/√Hz, the LMC6001 can achieve higher signal to noise ratio than JFET input type electrometer amplifiers. Other applications of the LMC6001 include long interval integrators, ultra-high input impedance instrumentation amplifiers, and sensitive electrical-field measurement circuits.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic