SLVUCG4 October   2022 TPSM82912 , TPSM82913

 

  1.   TPSM8291xEVM Evaluation Module
  2.   Trademarks
  3. 1Introduction
    1. 1.1 Performance Specification
    2. 1.2 Modifications
      1. 1.2.1 Input and Output Capacitors
      2. 1.2.2 Configurable Enable Threshold Voltage
      3. 1.2.3 NR/SS Capacitor
      4. 1.2.4 Feedforward Capacitor
      5. 1.2.5 S-CONF Resistor
      6. 1.2.6 Single LC Filter Operation
  4. 2Setup
    1. 2.1 Input and Output Connector Descriptions
    2. 2.2 Ripple Measurement Setup
  5. 3 Test Results
  6. 4 Board Layout
  7. 5Schematic and Bill of Materials
    1. 5.1 Schematic
  8. 6Bill of Materials

2.2 Ripple Measurement Setup

The extremely low noise and low ripple levels of the TPSM8291x necessitate a low-noise test setup for accurately measuring the output voltage ripple. The SMA connectors, J1 and J2, must be used to measure the output voltage ripple, before and after the second LC filter. Do not use a normal 10x oscilloscope probe with a high-impedance termination to the oscilloscope. Instead, connect the SMA connector directly to the oscilloscope with a coaxial (coax) cable through a DC blocker. A DC blocker enables the use of the smallest V/div setting on the oscilloscope to view the ripple. To prevent noise pickup and block reflections on the coax cable, the oscilloscope must be set to full bandwidth (BW) and DC coupling with a 50-Ω termination.