SBOSA87A December   2021  – November 2022 LMH5485-SEP

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: Vs+ – Vs- = 5 V
    6. 7.6 Electrical Characteristics: Vs+ – Vs- = 3 V
    7. 7.7 Typical Characteristics: 5 V Single Supply
    8. 7.8 Typical Characteristics: 3 V Single Supply
    9. 7.9 Typical Characteristics: 3 V to 5 V Supply Range
  8. Parameter Measurement Information
    1. 8.1 Example Characterization Circuits
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Differential I/O
      2. 9.3.2 Power-Down Control Pin (PD)
        1. 9.3.2.1 Operating the Power Shutdown Feature
      3. 9.3.3 Input Overdrive Operation
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation from Single-Ended Sources to Differential Outputs
        1. 9.4.1.1 AC-Coupled Signal Path Considerations for Single-Ended Input to Differential Output Conversion
        2. 9.4.1.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversion
      2. 9.4.2 Differential-Input to Differential-Output Operation
        1. 9.4.2.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
        2. 9.4.2.2 DC-Coupled, Differential-Input to Differential-Output Design Issues
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Designing Attenuators
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Interfacing to High-Performance ADCs
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

Overview

The LMH5485-SEP is a voltage-feedback (VFA) based, fully-differential amplifier (FDA) with a trimmed supply current and input offset voltage. The core differential amplifier is a slightly decompensated voltage-feedback design with a high slew-rate, precision input stage. This design gives a MHz gain of 2 V/V small-signal bandwidth shown in the characterization curves, with a V/µs slew rate, yielding approximately a MHz, 2 VPP, large-signal bandwidth in the same circuit configuration.

The outputs offer near rail-to-rail output swing (0.2 V headroom to either supply), while the device inputs are negative rail inputs with approximately 1.2 V of headroom required to the positive supply. Figure 8-2 shows how this negative rail input directly supports a bipolar input around ground in a DC-coupled, single-supply design. Similar to all FDA devices, the output average voltage (common-mode) is controlled by a separate common-mode loop. The target for this output average is set by the VOCM input pin that can be either floated to default near mid-supply or driven to a desired output common-mode voltage. The VOCM range extends from a very low 0.91 V above the negative supply to 1.1 V below the positive supply, supporting a wide range of modern analog-to-digital converter (ADC) input common-mode requirements using a single 2.7 V to 5.4 V supply range for the LMH5485-SEP.

A power-down pin (PD) is included. Pull the PD pin voltage to the negative supply to turn the device off, putting the LMH5485-SEP into a very-low quiescent current state. To be able to use the full supply range of the device, the device must be kept in normal operation by keeping the PD pin asserted high. When the device is disabled, remember that the signal path is still present through the passive external resistors. Input signals applied to a disabled LMH5485-SEP still appear at the outputs at some level through this passive resistor path as they would for any disabled FDA device.