SBOS008A September   2000  – September 2023 OPA177

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Revision History
  6. 5Pin Configuration and Functions
  7. 6Specifications
    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
    6. 6.6 Typical Characteristics
  8. 7Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Offset Voltage Adjustment
      2. 7.1.2 Input Protection
      3. 7.1.3 Noise Performance
      4. 7.1.4 Input Bias Current Cancellation
    2. 7.2 Typical Application
  9. 8Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 PSpice® for TI
        2. 8.1.1.2 TINA-TI™ Simulation Software (Free Download)
        3. 8.1.1.3 DIP-Adapter-EVM
        4. 8.1.1.4 DIYAMP-EVM
        5. 8.1.1.5 TI Reference Designs
        6. 8.1.1.6 Filter Design Tool
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • P|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1.4 Input Bias Current Cancellation

The input stage base current of the OPA177 is internally compensated with an equal and opposite cancellation current. The resulting input bias current is the difference between the input stage base current and the cancellation current. This residual input bias current can be positive or negative.

When the bias current is canceled in this manner, the input bias current and input offset current are approximately the same magnitude. As a result, there is no need to balance the dc resistance seen at the two input pins (Figure 7-2 and Figure 7-3). A resistor added to balance the input resistances can actually increase offset and noise.