SNOS694I March   1995  – September 2015 LMC6001

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  DC Electrical Characteristics for LMC6001AI
    6. 6.6  DC Electrical Characteristics for LMC6001BI
    7. 6.7  DC Electrical Characteristics for LMC6001CI
    8. 6.8  AC Electrical Characteristics for LMC6001AIC
    9. 6.9  AC Electrical Characteristics for LM6001BI
    10. 6.10 AC Electrical Characteristics for LMC6001CI
    11. 6.11 Dissipation Ratings
    12. 6.12 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Amplifier Topology
      2. 7.3.2 Latch-Up Prevention
    4. 7.4 Device Functional Modes
  8. 8 Applications and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Compensating For Input Capacitance
      2. 8.1.2 Capacitive Load Tolerance
    2. 8.2 Typical Application
      1. 8.2.1 Two Op Amp, Temperature Compensated Ph Probe Amplifier
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
    3. 8.3 System Example
      1. 8.3.1 Ultra-Low Input Current Instrumentation Amplifier
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Printed-Circuit-Board Layout For High-Impedance Work
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7 Detailed Description

7.1 Overview

LMC6001 has an extremely low input current of 25 fA. In addition, its ultra-low input current noise of 0.13 fA/√Hz allows almost noiseless amplification of high-resistance signal sources. LMC6001 is ideally suited for electrometer applications requiring ultra-low input leakage current such as sensitive photodetection transimpedance amplifiers and sensor amplifiers.

7.2 Functional Block Diagram

LMC6001 1188701.png

7.3 Feature Description

7.3.1 Amplifier Topology

The LMC6001 incorporates a novel op amp design topology that enables it to maintain rail-to-rail output swing even when driving a large load. Instead of relying on a push-pull unity gain output buffer stage, the output stage is taken directly from the internal integrator, which provides both low output impedance and large gain. Special feed-forward compensation design techniques are incorporated to maintain stability over a wider range of operating conditions than traditional op amps. These features make the LMC6001 both easier to design with, and provide higher speed than products typically found in this low-power class.

7.3.2 Latch-Up Prevention

CMOS devices tend to be susceptible to latch-up due to their internal parasitic SCR effects. The (I/O) input and output pins look similar to the gate of the SCR. There is a minimum current required to trigger the SCR gate lead. The LMC6001 is designed to withstand 100-mA surge current on the I/O pins. Some resistive method should be used to isolate any capacitance from supplying excess current to the I/O pins. In addition, like an SCR, there is a minimum holding current for any latch-up mode. Limiting current to the supply pins will also inhibit latch-up susceptibility.

7.4 Device Functional Modes

The LMC6001 has a single functional mode and operates according to the conditions listed in Recommended Operating Conditions.