SBASB81 December   2024 AFE5401-EP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1.     Pin Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics
    6. 5.6  Digital Characteristics
    7. 5.7  Timing Requirements: Output Interface
    8. 5.8  Timing Requirements: RESET
    9. 5.9  Timing Requirements: Serial Interface Operation
    10. 5.10 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Timing Requirements: Across Output Serialization Modes
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Low-Noise Amplifier (LNA)
      2. 7.3.2 Programmable Gain Amplifier (PGA)
      3. 7.3.3 Antialiasing Filter
      4. 7.3.4 Analog-to-Digital Converter (ADC)
      5. 7.3.5 Digital Gain
      6. 7.3.6 Input Clock Divider
      7. 7.3.7 Data Output Serialization
      8. 7.3.8 Setting the Input Common-Mode Voltage for the Analog Inputs
        1. 7.3.8.1 Main Channels
        2. 7.3.8.2 Auxiliary Channel
    4. 7.4 Device Functional Modes
      1. 7.4.1 Equalizer Mode
      2. 7.4.2 Data Output Mode
        1. 7.4.2.1 Header
        2. 7.4.2.2 Test Pattern Mode
      3. 7.4.3 Parity
      4. 7.4.4 Standby, Power-Down Mode
      5. 7.4.5 Digital Filtering to Improve Stop-Band Attenuation
        1. 7.4.5.1 Decimate-by-2 Mode
        2. 7.4.5.2 Decimate-by-4 Mode
      6. 7.4.6 Diagnostic Mode
      7. 7.4.7 Signal Chain Probe
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
      2. 7.5.2 Register Initialization
        1. 7.5.2.1 Register Write Mode
        2. 7.5.2.2 Register Read Mode
      3. 7.5.3 CMOS Output Interface
        1. 7.5.3.1 Synchronization and Triggering
    6. 7.6 Register Maps
      1. 7.6.1 Functional Register Map
      2. 7.6.2 Register Descriptions
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power Supply Sequencing
      2. 8.3.2 Power Supply Decoupling
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Revision History
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Community Resources
    4. 10.4 Trademarks
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.8.1 Main Channels

The device analog input consists of a differential LNA. The common-mode for the LNA inputs is internally set using two internal, programmable, single-ended resistors, as shown in Figure 7-7.

AFE5401-EP Common-Mode Biasing of LNA Input PinsFigure 7-7 Common-Mode Biasing of LNA Input Pins

These resistors can be programmed to a higher value using the TERM_INT_20K_LNA register setting as described in Table 7-8.

Table 7-8 Internal Termination Register Setting (LNA)
TERM_INT_20K_LNADESCRIPTION
0RINTTERM_LNA = 1 kΩ
1RINTTERM_LNA = 10 kΩ

Hence, for proper operation, the input signal must be ac-coupled. Note that external input ac-coupling capacitors form a high-pass filter (HPF) with RINTTERM_LNA. Therefore, the capacitor values should allow the lowest frequency of interest to pass with minimum attenuation. For typical frequencies greater than 1 MHz, a value of 50 nF or greater is recommended. The maximum input swing is limited by the LNA gain setting. LNA output swing is limited to 2 VPP before the output becomes saturated or distorted.

Single ended mode of operation is also possible by connecting non-driven input pin to ground through a capacitor of 100 nF. However, this will result in reduced linearity.