SLVU346A January   2010  – February 2022 TPS51218

 

  1.   Trademarks
  2. 1Description
    1. 1.1 Typical Applications
    2. 1.2 Features
  3. 2Electrical Performance Specifications
  4. 3Schematic
  5. 4Test Setup
    1. 4.1 Test Equipment
    2. 4.2 Recommended Test Setup
      1. 4.2.1 Configurations
      2. 4.2.2 Input Connections
      3. 4.2.3 Output Connections
      4. 4.2.4 Other Connections
  6. 5Test Procedure
    1. 5.1 Line/Load Regulation and Efficiency Measurement Procedure
    2. 5.2 List of Test Points
    3. 5.3 Equipment Shutdown
  7. 6Performance Data and Typical Characteristic Curves
    1. 6.1 Efficiency
    2. 6.2 Load Regulation
    3. 6.3 Transient Response
    4. 6.4 Output Ripple
    5. 6.5 Switch Node Voltage
    6. 6.6 Turn-On Waveform
    7. 6.7 Turn-Off Waveform
    8. 6.8 Output 1.1-V Prebias Turn-On
  8. 7EVM Assembly Drawing and PCB Layout
  9. 8Bill of Materials
  10. 9Revision History

4.1 Test Equipment

Voltage Source: The input voltage source, VIN, must be a 0-V to 14-V variable DC source capable of supplying 10 ADC. Connect VIN to J1 as shown in Figure 4-2.

Multimeters: A 0-V to 15-V voltmeter must be used to measure VIN at TP6 (VIN) and TP7 (PGND) and a 0-V to 5-V voltmeter for VOUT measurement at TP8 (VOUT) and TP9 (PGND). A 0-A to 10-A current meter (A1) as shown in Figure 4-2 is used for input current measurements.

Output Load: The output load must be an electronic constant resistance mode load capable of 0 ADC to 30 ADC at 1.2 V.

Oscilloscope: A digital or analog oscilloscope can be used to measure the output ripple. The oscilloscope must be set for the following:

  • 1-MΩ impedance
  • 20-MHz bandwidth
  • AC coupling
  • 2-µs/division horizontal resolution
  • 50-mV/division vertical resolution

Test points TP8 and TP9 can be used to measure the output ripple voltage by placing the oscilloscope probe tip through TP8 and holding the ground barrel TP9 as shown in Figure 4-1. Using a leaded ground connection can induce additional noise due to the large ground loop.

GUID-F61171D6-196B-4BAB-BE2C-745F7EEDA124-low.gifFigure 4-1 Tip and Barrel Measurement for VOUT Ripple

Fan: Some of the components in this EVM can get hot, approaching temperatures up to 60°C during operation. A small fan capable of 200 to 400 LFM is recommended to reduce component temperatures while the EVM is operating. The EVM must not be probed while the fan is not running.

Recommended Wire Gauge: For VIN to J1 (12-V input), the recommended wire size is 1× AWG 14 per input connection, with the total length of wire less than four feet (2-foot input, 2-foot return). For J2 to LOAD, the minimum recommended wire size is 2× AWG 14, with the total length of wire less than four feet (2-foot output, 2-foot return).