SBOU282A December   2022  – March 2023 OPA928

 

  1.   Abstract
  2.   Trademarks
  3. 1Read This First
    1. 1.1 EVM Cleanliness Guidelines
  4. 2Overview
    1. 2.1 Guarding and Shielding
  5. 3Getting Started
    1. 3.1 Related Documentation From Texas Instruments
    2. 3.2 Electrostatic Discharge Caution
  6. 4EVM Circuit Description
    1. 4.1 High-Impedance Amplifier Circuit
    2. 4.2 Transimpedance Amplifier Circuit
      1. 4.2.1 Configure the TIA
      2. 4.2.2 TIA Functions
        1. 4.2.2.1 T-Switch
        2. 4.2.2.2 Guarded Diode Limiter
  7. 5Cleaning the EVM
    1. 5.1 Ultrasonic Wash
    2. 5.2 Manual Cleaning Procedure
  8. 6Schematic, PCB Layout, and Bill of Materials
    1. 6.1 EVM Schematic
    2. 6.2 PCB Layout
    3. 6.3 Bill of Materials

5.2 Manual Cleaning Procedure

  1. Flush contaminants from the EVM.
    1. Hold the board by the edges and flush the top and bottom using a combination of fresh isopropyl alcohol (IPA) and fresh DI water. Focus on the input traces, guard copper, and feedback components.
  2. Scrub contaminants from top side of the EVM.
    1. Hold the board by the edges with the top layer facing up. Flood sensitive input and feedback areas with fresh IPA.
    2. Use a toothbrush to gently scrub for 30–60 seconds. Focus on the areas surrounding P1, P2, JP2, JP3, SH1, and the area directly right of J1.
    3. Flush the scrubbed areas with fresh DI water, tilting the board to allow runoff to flow away from the input areas.
  3. Scrub contaminants from the bottom layer TIA input.
    1. Hold the board by the edges with the bottom layer facing up. Flood sensitive input and feedback areas with fresh IPA.
    2. Use a toothbrush to gently scrub for 30–60 seconds. Focus on areas surrounding U2, R4, Rf, Cf, K2, K1, U1, R1, and all input and guard traces.
    3. Flush the scrubbed areas with fresh DI water, tilting the board to allow runoff to flow away from the input areas.
  4. Remove moisture from the PCB.
    1. Bake the EVM for two hours at 100°C.