SBOS710D October   2014  – February 2018 LMH5401

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Distortion versus Frequency (G = 12 dB, SE-DE, RL = 200 Ω, VPP = 2 V)
  3. 3 Description
    1.     LMH5401 Driving an ADC12J4000
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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: VS = 5 V
    6. 6.6 Electrical Characteristics: VS = 3.3 V
    7. 6.7 Typical Characteristics: 5 V
    8. 6.8 Typical Characteristics: 3.3 V
    9. 6.9 Typical Characteristics: 3.3-V to 5-V Supply Range
  7. 7 Parameter Measurement Information
    1. 7.1  Output Reference Points
    2. 7.2  ATE Testing and DC Measurements
    3. 7.3  Frequency Response
    4. 7.4  S-Parameters
    5. 7.5  Frequency Response with Capacitive Load
    6. 7.6  Distortion
    7. 7.7  Noise Figure
    8. 7.8  Pulse Response, Slew Rate, and Overdrive Recovery
    9. 7.9  Power Down
    10. 7.10 VCM Frequency Response
    11. 7.11 Test Schematics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Fully-Differential Amplifier
        1. 8.3.1.1 Power Down and Ground Pins
      2. 8.3.2 Operations for Single-Ended to Differential Signals
        1. 8.3.2.1 AC-Coupled Signal Path Considerations for Single-Ended Input to Differential Output Conversion
        2. 8.3.2.2 DC-Coupled Input Signal Path Considerations for SE-DE Conversions
        3. 8.3.2.3 Resistor Design Equations for Single-to-Differential Applications
        4. 8.3.2.4 Input Impedance Calculations
      3. 8.3.3 Differential-to-Differential Signals
        1. 8.3.3.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
        2. 8.3.3.2 DC-Coupled, Differential-Input to Differential-Output Design Issues
      4. 8.3.4 Output Common-Mode Voltage
      5. 8.3.5 LMH5401 Comparison
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation With a Split Supply
      2. 8.4.2 Operation With a Single Supply
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Stability
      2. 9.1.2 Input and Output Headroom Considerations
      3. 9.1.3 Noise Analysis
      4. 9.1.4 Noise Figure
      5. 9.1.5 Thermal Considerations
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Driving Matched Loads
        2. 9.2.2.2 Driving Unmatched Loads For Lower Loss
        3. 9.2.2.3 Driving Capacitive Loads
        4. 9.2.2.4 Driving ADCs
          1. 9.2.2.4.1 SNR Considerations
          2. 9.2.2.4.2 SFDR Considerations
          3. 9.2.2.4.3 ADC Input Common-Mode Voltage Considerations : AC-Coupled Input
          4. 9.2.2.4.4 ADC Input Common-Mode Voltage Considerations : DC-Coupled Input
        5. 9.2.2.5 GSPS ADC Driver
        6. 9.2.2.6 Common-Mode Voltage Correction
        7. 9.2.2.7 Active Balun
      3. 9.2.3 Application Curves
    3. 9.3 Do's and Don'ts
      1. 9.3.1 Do:
      2. 9.3.2 Don't:
  10. 10Power Supply Recommendations
    1. 10.1 Supply Voltage
    2. 10.2 Single-Supply
    3. 10.3 Split-Supply
    4. 10.4 Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Device Nomenclature
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7.3 Frequency Response

This test is run with single-ended inputs and differential inputs.

For tests with single-ended inputs, the standard EVM is used with no changes; see Figure 56. To provide a matched input, the unused input requires a broadband 50-Ω termination to connect. When using a four-port network analyzer, the unused input can be terminated with a broadband load, or can connect to the unused input on the four-port analyzer. The network analyzer provides proper termination. A network analyzer connects to the input and output of the EVM with 50-Ω coaxial cables and measures the forward transfer function (s21). The input signal frequency is swept with the signal level set for the required output amplitude.

The LMH5401 is fully symmetrical. Either input (IN+ or IN–) can be used for single-ended inputs. The unused input must be terminated. RF, RG1, and RG2 determine the gain. RT and RM enable matching to the source resistance. See the Test Schematics section for more information on setting these resistors per gain and source impedance requirements. Bandwidth is dependant on gain settings because this device is a voltage feedback amplifier. With a GBP of 8 GHz, the approximate bandwidth is calculated for a specific application requirement, as shown in Equation 2. Figure 57 shows a test schematic for differential input and output.

Equation 2. GBP (Hz) = BW (Hz) × Noise Gain

For tests with differential inputs, the same setup for single-ended inputs is used except all four connectors are connected to a network analyzer port. Measurements are made in true differential mode on the Rohde & Schwarz® network analyzer or in calculated differential mode. In each case, the differential inputs are each driven with a 50-Ω source. Table 1 and Table 2 lists the resistor values used in frequency response sweeps.

Table 1. Differential Input/Output

AV (V/V)RG1, RG2 (Ω)RF (TOTAL / EXTERNAL, Ω)RT (Ω)
2 100 199 / 174 100
4 49.9 199 / 174 N/A
6 49.9 300 / 274 N/A
8 49.9 400 / 375 N/A
10 49.9 500 / 475 N/A

Table 2. SE Input

AV (V/V)RG1 (Ω)RT (Ω)RG2 (Ω)RF (TOTAL / EXTERNAL, Ω)
2 90.9 76.8 121 200 / 175
4 22.6 357 66.5 152 / 127
8 12.1 1100 60.4 250 / 225
10 9.76 1580 57.6 300 / 275