SBOSA33A September   2021  – December 2021 LMH5485-SP

ADVANCE INFORMATION  

  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  Quality Conformance Inspection
    8. 7.8  Typical Characteristics: 5 V Single Supply
    9. 7.9  Typical Characteristics: 3 V Single Supply
    10. 7.10 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
      1. 9.1.1 Terminology and Application Assumptions
    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
        3. 9.4.1.3 Resistor Design Equations for the Single-Ended to Differential Configuration of the FDA
        4. 9.4.1.4 Input Impedance for the Single-Ended to Differential FDA Configuration
      2. 9.4.2 Differential-Input to Differential-Output Operation
        1. 9.4.2.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Tube Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

Overview

The LMH5485-SP is a voltage-feedback (VFA) based, fully-differential amplifier (FDA) offering greater than 490 MHz, small-signal bandwidth at a gain of 2 V/V with 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 the 490495 MHz gain of 2 V/V small-signal bandwidth shown in the characterization curves, with a 14001300 V/µs slew rate, yielding approximately a 315295 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 8-3 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 5.1 V supply range for the LMH5485-SP.

A power-down pin (PD) is included. Pull the PD pin voltage to the negative supply to turn the device off, putting the LMH5485-SP into a very-low quiescent current state. For normal operation, the PD pin must be 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-SP still appear at the outputs at some level through this passive resistor path as they would for any disabled FDA device.