DEMO MANUAL DC2448A-C LTM4636 High Efficiency, PolyPhase 160A Step-Down Power Module Regulator DESCRIPTION Demonstration circuit DC2448A-C features a PolyPhase pulse-skipping mode for noise sensitive applications or design using the LTM 4636EY, a 40A high efficiency, Burst Mode operation in less noise sensitive applica- switch mode step-down power Module regulator. The tions. The MODE PLLIN pin also allows the LTM4636 to input voltage range is from 4.7V to 15V. When V <5.5V, synchronize to an external clock signal. The phases of the IN short PVCC to VIN with R1 = 0, and set R3 = 0 and four LTM4636s are 0 degree, 90 degree, 180 degree and remove R2. The output voltage range is 0.6V to 3.3V. 270 degree. DC2448A-C has the option of choosing both The DC2448A-C can deliver a nominal 160A output internal and external compensation circuit for LTM4636. current. As explained in the data sheet, output current The LTM4636 datasheet must be read in conjunction with derating is necessary for certain V , V and thermal this demo manual prior to working on or modifying demo IN OUT conditions. The board operates in continuous conduc- circuit DC2448A-C. tion mode in heavy load conditions. For high efficiency Design files for this circuit board are available. at low load currents, the MODE PLLIN jumper selects All registered trademarks and trademarks are the property of their respective owners. BOARD PHOTO Rev. 0 1DEMO MANUAL DC2448A-C PERFORMANCE SUMMARY Specifications are at T = 25C A PARAMETER CONDITIONS VALUE Input Voltage Range 4.7V to 15V Output Voltages 0.9V 1.3% Maximum Continuous Output Current Derating is necessary for certain operating conditions. See data sheet for details. 160A DC Operating Frequency 350kHz Efficiency V = 12V, V = 0.9V, I = 160A 86.1% Figure 2 IN OUT OUT Load Transient V V = 12V, V = 0.9V, I = 0A TO 40A 91mV Figure 3 OUT(P-P) IN OUT STEP QUICK START PROCEDURE Demonstration circuit DC2448A-C is an easy way to 4. Vary the input voltage from 6V to 15V and adjust the evaluate the performance of PolyPhase operation of the load current from 0A to 160A. Observe the output LTM4636EY. Due to the high input/output current, the voltage regulation, ripple voltage, efficiency and other user should select the proper input supply/load/cable parameters. which can sustain the full load operation. Please refer to 5. (Optional) For optional load transient test, apply an Figure 1 for proper measurement equipment setup and adjustable pulse signal between IOSTEP CLK and GND follow the procedure below: test points. The pulse amplitude sets the load step cur- 1. Place jumpers in the following positions for a typical rent amplitude. Keep the pulse width short (<1ms) and application: pulse duty cycle low (<5%) to limit the thermal stress on the load transient circuit. MODE RUN 6. (Optional) LTM4636 can be synchronized to an external CCM ON clock signal. Apply a clock signal (0V to 5V, square wave) on the MODE PLLIN test point. 2. With power off, connect the input power supply, load 7. (Optional) The outputs of LTM4636 can track another and meters as shown in Figure 1. Preset the load to 0A supply. The output voltage tracks the voltage on TRACK and V supply to 12V. IN when a valid signal is applied on the test point. 3. Turn on the power supply at the input. The output volt- age should be 0.9V 1.3% (0.888V to 0.912V). Rev. 0 2