DC1872A Analog Devices

DEMO MANUAL DC1872A LTM4637 20A DC/DC Module Step-Down Regulator DESCRIPTION Demonstration circuit DC1872A features the LTM 4637EV, choose pulse-skipping mode or Burst Mode operation a high efficiency, high density switch mode step-down for higher efficiency at light load conditions. power Module regulator. The input voltage range is The LTM4637 data sheet must be read in conjunction with from 4.5V to 20V. The output voltage is jumper pro- this demo manual prior to working on or modifying demo grammable from 1.0V to 1.8V with a rated load current circuit DC1872A. of 20A. Derating is necessary for certain V , V , fre- IN OUT Design files for this circuit board are available at quency and thermal conditions. The DC1872A offers the DEMO MANUAL DC1872A QUICK START PROCEDURE Demonstration circuit DC1872A is an easy way to eva- 4. Vary the input voltage from 4.5V to 20V and adjust luate the performance of the LTM4637EV. Please refer to the load current from 0A to 20A. Observe the output Figure 1 for proper measurement equipment setup and voltage regulation, ripple voltage, efficiency, and other follow the procedure below: parameters. Output voltage ripple may be measured at J4 with a BNC cable and oscilloscope. The probe channel 1. Place jumpers in the following positions for a typical for V should be set at 50 termination resistance OUT 1.0V application: OUT to match the BNC cable. RUN MODE TRACK/SS VOUT SELECT 5. (Optional) For optional load transient test, apply an ON CCM SS 1.0V adjustable pulse signal between IOSTEP CLK and GND test points. The pulse amplitude sets the load step cur- 2. With power off, connect the input power supply, load rent amplitude. Keep the pulse width short (<1ms) and and meters as shown in Figure 1. Preset the load to pulse duty cycle low (<5%) to limit the thermal stress 0A and V supply to be 0V. IN on the load transient circuit. The load step current can 3. Turn on the power at the input. Increase V to 12V (Do IN be monitored with a BNC connected to J3 (15mV/A). not apply more than the rated maximum voltage of 20V to the board or the part may be damaged). The output voltage should be regulated and deliver the selected output voltage 1.5%. LOAD + V V IN + DC1872A F01 Figure 1. Proper Measurement Equipment Setup dc1872af 2 A + + + A + V