SBOSA51 December   2020 THS4567

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 Electrical Characteristics: Differential TIA Mode, ICM loop enabled
    6. 6.6 Electrical Characteristics: FDA operation, ICM loop disabled
    7. 6.7 Typical Characteristics: (VS+) – (VS–) = 5 V
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Main Amplifier
      2. 7.3.2 Output Common-Mode Control
      3. 7.3.3 Input Common-Mode Control
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Differential Transimpedance Amplifier Mode
      3. 7.4.3 Fully Differential Amplifier (FDA) Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Noise Analysis
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure (THS4567 in TIA Mode)
        1. 8.2.2.1 OPA Mode Configuration
      3. 8.2.3 Application Curves
    3. 8.3 Differential TIA with 0-V Biased Photodiode
    4. 8.4 Differential AC Coupled TIA
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Board Layout Recommendations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.3.3 Input Common-Mode Control

The THS4567 device features a unique input common-mode control error amplifier that sets the input common-mode voltage independent of the output common-mode voltage. The VICM error amplifier works by sensing the average voltage at the main amplifiers inputs and then sourcing or sinking an equal amount of current into both the input nodes of the main amplifier to maintain the input common-mode voltage equal to voltage at the VICM pin. If the VICM pin is left floating, its input voltage defaults to 1.5-V above VS–. This voltage is set by the combination of the 8-µA current source and the 181-kΩ resistor shown in Section 7.2. When using the VICM at its default voltage, connect an external capacitor to the VICM pin to bypass the noise from the internal 181-kΩ resistor. The VICM voltage can be set to an arbitrary value by driving the VICM pin externally through a low output impedance source. The input common-mode control loop can be disabled by setting ICM_EN pin low. With the input common-mode loop disabled the THS4567 device behaves like a standard fully-differential amplifier (FDA).