SLUU818A April   2012  – February 2022 TPS51219

 

  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
  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 Line Regulation
    4. 6.4 Load Transient
    5. 6.5 Output Ripple
    6. 6.6 Switch Node Voltage
    7. 6.7 Turn-On/Turn-Off Waveform
    8. 6.8 Output 0.5-V Prebias Turnon Waveform
  8. 7EVM Assembly Drawing and PCB Layout
  9. 8Bill of Materials
  10. 9Revision History

4.1 Test Equipment

Voltage Source VIN: The input voltage source VIN must be a 0-V to 20-V variable DC source capable of supplying 10 ADC. Connect VIN to J4 as shown in Figure 4-2.

Voltage Source V5IN: The input voltage source V5IN must be a 0-V to 5-V variable DC source capable of supplying 1 ADC. Connect V5IN to J1 as shown in Figure 4-2.

Multimeters:

  • V1: VIN at TP11 (VIN) and TP12 (VIN_GND)
  • V2: V5IN at TP10 (V5IN) and TP9 (V5IN_GND)
  • V3: VSNS at J6-2 and GSNS at J6-1
  • A1: VIN input current
  • A2: V5IN input current

Output Load: The output load must be an electronic constant-resistance mode load capable of 0 ADC to 30 ADC at 1.05 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
  • 1-µs/division horizontal resolution
  • 20-mV/division vertical resolution

Test point J6 can be used to measure the differential output ripple voltage, using a passive probe with the shortest leaded ground clip. For switch node voltage measurement, TP7 and TP8 can be used by placing the passive probe tip through TP7 and holding the ground barrel TP8 as shown in Figure 4-1. In this case, using a leaded ground connection may induce additional noise due to the large ground loop.

GUID-6A5B8A72-0E58-4224-8DEA-610661AE9B3B-low.gifFigure 4-1 Tip and Barrel Measurement for Switch Node Voltage

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

Recommended Wire Gauge:

  1. VIN to J4 (8-V to 20-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).
  2. V5IN to J1 (5-V input)
    The recommended wire size is 1× AWG 18 per input connection, with the total length of wire less than four feet (2-foot input, 2-foot return).
  3. J12 to LOAD
    The minimum recommended wire size is 2× AWG 14, with the total length of wire less than four feet (2-foot input, 2-foot return).