Texas Instruments LM5145EVM-HD-20A Buck Controller EVM

Texas Instruments LM5145EVM-HD-20A Buck Controller Evaluation Module (EVM) is designed to showcase the performance of the LM5145. The LM5145 is a high-performance, synchronous DC-DC buck controller with a wide input voltage range. The evaluation module is packaged in a small footprint with a low component count. The module operates over a wide input voltage range of 24V to 72V to deliver a fixed 5V output with better than 1% set point accuracy and currents up to 20A. The Texas Instruments LM5145EVM-HD-20A free-running switching frequency is 220kHz and is synchronizable to a higher or lower frequency if required.

Features

24V to 72V input voltage range
Fully assembled, tested, and proven PCB layout with 30mm x 15mm total footprint
Delivers up to 20A of load current

A free-running switching frequency of 220kHz, synchronizable to an external clock from -20% to +50%
5V output voltage, adjustable from 3.3V to 8V

Required Equipment

Electronic Load
- The load should be an electronic constant-resistance (CR) or constant-current (CC) mode load capable of 0ADC to 20ADC at 5V
- For a no-load input current measurement, disconnect the electronic load as it may draw a small residual current
Oscilloscope
- With the scope set to 20MHz bandwidth and AC coupling, measure the output voltage ripple directly across an output capacitor with a short ground lead normally provided with the scope probe
- Place the oscilloscope probe tip on the positive terminal of the output capacitor, holding the probe's ground barrel through the ground lead to the capacitor's negative terminal
- TI does not recommend using a long-leaded ground connection because this may induce additional noise given a large ground loop
- To measure other waveforms, adjust the oscilloscope as needed

Voltage Source
- The input voltage source V_IN should be a 0–72V variable DC source capable of supplying 10A
Multimeters
- Voltmeter 1
  - Input voltage at V_IN to GND
  - Set the voltmeter to an input impedance of 100MΩ
- Voltmeter 2
  - Output voltage at V_OUT to GND
  - Set the voltmeter to an input impedance of 100MΩ
- Ammeter 1
  - Input current
  - Set the ammeter to a 1-second aperture time
- Ammeter 2
  - Output current
  - Set the ammeter to a 1-second aperture time