SBOSA05C August   2021  – November 2022 LMH32404

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
    6. 6.6 Electrical Characteristics: Logic Threshold and Switching Characteristics
    7. 6.7 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 Clamping and Input Protection
      2. 7.3.2 ESD Protection
      3. 7.3.3 Differential Output Stage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Ambient Light Cancellation (ALC) Mode
      2. 7.4.2 Channel Multiplexer Mode
      3. 7.4.3 Low-Power Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Standard TIA Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Increase Channel Density for Optical Front-End Systems
        1. 8.2.2.1 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.1.2 Detailed Design Procedure

Figure 8-3 and Figure 8-4 shows the LMH32404 test circuit used to measure its bandwidth, noise and transient response. The voltage source is DC biased close to the input bias voltage of the LMH32404. The LMH32404 internal design is optimized to only source current out of the input pin (INx). When testing the LMH32404 with a network analyzer or sinusoidal source, set the DC bias such that sum of the input AC and DC component does not result in a sourcing current into the amplifier input. Only use the LMH32404 with avalanche photodiodes (APDs) that sink current. An anode-biased APD satisfies this requirement.

Figure 8-5 shows the measured results for bandwidth of LMH32404 for all four channels.

Figure 8-6 shows the output noise spectral density of the LMH32404 with CAPD = 1 pF and no photodiode capacitance.

Figure 8-7 shows the turn-on time of the LMH32404 channel when the Mx pin is toggled from logic low to high. When the amplifier is off, the output is in a high-impedance state. When the amplifier turns on, the output settles and starts tracking the input within a few nanoseconds.

Figure 8-8 shows the turn-off time of the LMH32404 channel when the Mx pin is toggled from logic high to low. When the amplifier is off, the output is in a high-impedance state.