SNOS674G November   1997  – April 2020 LMC6482

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Rail-to-Rail Input
      2.      Rail-to-Rail Output
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Electrical Characteristics for V+ = 5 V
    6. 6.6 Electrical Characteristics for V+ = 3 V
    7. 6.7 Typical Characteristics
  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 Input Common-Mode Voltage Range
      3. 7.3.3 Rail-to-Rail Output
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Upgrading Applications
      2. 8.1.2 Data Acquisition Systems
      3. 8.1.3 Instrumentation Circuits
      4. 8.1.4 Spice Macromodel
    2. 8.2 Typical Applications
      1. 8.2.1 3-V Single-Supply Buffer Circuit
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Capacitive Load Compensation
          2. 8.2.1.2.2 Capacitive Load Tolerance
          3. 8.2.1.2.3 Compensating For Input Capacitance
          4. 8.2.1.2.4 Offset Voltage Adjustment
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Single-Supply Applications
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

Typical Single-Supply Applications

The circuit in Figure 69 uses a single supply to half-wave rectify a sinusoid centered about ground. RI limits current into the amplifier caused by the input voltage exceeding the supply voltage. Full-wave rectification is provided by the circuit in Figure 71.

LMC6482 01171331.pngFigure 69. Half-Wave Rectifier With Input Current Protection (RI)
LMC6482 01171332.pngFigure 70. Half-Wave Rectifier Waveform

In Figure 75 dielectric absorption and leakage is minimized by using a polystyrene or polyethylene hold capacitor. The droop rate is primarily determined by the value of CH and diode leakage current. The ultra-low input current of the LMC6482 has a negligible effect on droop.

LMC6482 01171333.pngFigure 71. Full-Wave Rectifier With Input Current Protection (RI)
LMC6482 01171335.pngFigure 73. Large Compliance Range Current Source
LMC6482 01171337.pngFigure 75. Low-Voltage Peak Detector With Rail-To-Rail Peak Capture Range
LMC6482 01171334.pngFigure 72. Full-Wave Rectifier Waveform
LMC6482 01171336.pngFigure 74. Positive Supply Current Sense

The high CMRR (82 dB) of the LMC6482 allows excellent accuracy throughout the rail-to-rail dynamic capture range of the circuit.

LMC6482 01171338.pngFigure 76. Rail-To-Rail Sample and Hold

The low-pass filter circuit in Figure 77 can be used as an antialiasing filter with the same voltage supply as the A/D converter.

Filter designs can also take advantage of the LMC6482 ultra-low input current. The ultra-low input current yields negligible offset error even when large value resistors are used. This in turn allows the use of smaller valued capacitors that take less board space and cost less.

LMC6482 01171327.pngLMC6482 01171393.pngFigure 77. Rail-To-Rail Single Supply Low Pass Filter