SLOU587B February   2025  – May 2026

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  7. 2Hardware
    1. 2.1 Additional Images
      1. 2.1.1 Pin Configuration
    2. 2.2 Power Requirements
    3. 2.3 Header Information
    4. 2.4 Jumper Information
    5. 2.5 Laser Diode
    6. 2.6 Snubber
  8. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB Layouts
    3. 3.3 Bill of Materials (BOM)
  9. 4Additional Information
    1. 4.1 Trademarks
  10. 5Revision History

2.3 Header Information

J_EP and J_EN: These two SMA connectors are for the positive (EP) and negative (EN) LVDS inputs of the device, respectively. By default in Rev.C EVM (AMPS251C), these connectors are terminated with 100Ω resistor (R7+R10) differentially as per the LVDS standard. To operate the device and the EVM on a single-ended input, short jumper J1 and short resistor R22, and depopulate R10. In this configuration, the EN pin get biased to midsupply. A single-ended signal with a voltage level that crosses the midsupply voltage can then be provided to the EP pin to switch the device output current.

J_VSET: This SMA connector is used to provide voltage to the VSET pin of the device, and thus sets the current value at the output. Apply an appropriate voltage between 0.2V to 2V to this connector to control IOUT. Alternatively, remove R20 and connect R11 to control the voltage at VSET from the onboard resistor divider by adjusting potentiometer R8.

J_PD: This SMA connector connects to the power-down pin (PD) of the device. To power down the device, pull the PD pin to greater than AVDD – 1.2V. To enable the device, pull the PD pin voltage to less than AGND + 1.2V.

J_TIA_OUT: The onboard TIA (U2) outputs to this SMA connector. The TIA senses current from the back facet diode of the laser and converts the current to a voltage-level based on the gain set by R12.