SLOS099G October   1983  – November 2014 OP07C , OP07D

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Simplified Schematic
  5. Revision History
  6. Pin Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Operating Characteristics
  8. Typical Characteristics
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Offset-Voltage Null Capability
      2. 9.3.2 Slew Rate
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 General Application
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Output Voltage Swing
        2. 10.2.2.2 Supply and Input Voltage
      3. 10.2.3 Application Curves for Output Characteristics
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Related Links
      1. 13.1.1 Trademarks
      2. 13.1.2 Electrostatic Discharge Caution
    2. 13.2 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10 Application and Implementation

10.1 General Application

The input offset voltage of operational amplifiers (op amps) arises from unavoidable mismatches in the differential input stage of the op-amp circuit caused by mismatched transistor pairs, collector currents, current-gain betas (β), collector or emitter resistors, etc. The input offset pins allow the designer to adjust for these mismatches by external circuitry. These input mismatches can be adjusted by putting resistors or a potentiometer between the inputs as shown in Figure 2. A potentiometer can be used to fine tune the circuit during testing or for applications which require precision offset control. More information about designing using the input-offset pins, see Nulling Input Offset Voltage of Operational Amplifiers(SLOA045).

apps_los099.gifFigure 2. Input Offset-Voltage Null Circuit

10.2 Typical Application

The voltage follower configuration of the operational amplifier is used for applications where a weak signal is used to drive a relatively high current load. This circuit is also called a buffer amplifier or unity gain amplifier. The inputs of an operational amplifier have a very high resistance which puts a negligible current load on the voltage source. The output resistance of the operational amplifier is almost negligible, so it can provide as much current as necessary to the output load.

app_sch.gifFigure 3. Voltage Follower Schematic

10.2.1 Design Requirements

  • Output range of 2 V to 11 V
  • Input range of 2 V to 11 V

10.2.2 Detailed Design Procedure

10.2.2.1 Output Voltage Swing

The output voltage of an operational amplifier is limited by its internal circuitry to some level below the supply rails. For this amplifier, the output voltage swing is within ±12 V, which accommodates the input and output voltage requirements.

10.2.2.2 Supply and Input Voltage

For correct operation of the amplifier, neither input must be higher than the recommended positive supply rail voltage or lower than the recommended negative supply rail voltage. The chosen amplifier must be able to operate at the supply voltage that accommodates the inputs. Because the input for this application goes up to
11 V, the supply voltage must be 12 V. Using a negative voltage on the lower rail, rather than ground, allows the amplifier to maintain linearity for inputs below 2 V.

10.2.3 Application Curves for Output Characteristics

C001_SLOS099.pngFigure 4. Output Voltage vs Input Voltage
C003_SLOS099.pngFigure 6. Current Drawn from Supply (ICC) vs the Input Voltage
C002_SLOS099.pngFigure 5. Current Drawn by the Input of the Voltage Follower (IIO) vs the Input Voltage