DEMO MANUAL DC2121A LTM4634 Triple Output 5A/5A/4A Step-Down DC/DC Module Regulator Description Demonstration circuit 2121A features the LTM 4634, a mode for noise sensitive applications or Burst Mode high efficiency, triple 5A/5A/4A step-down power Module operation in less noise sensitive applications. Channel 1 regulator. The input voltage range is from 4.75V to 28V. and 2 can be connected in parallel for a single 10A output The output voltage range is 0.8V to 5.5V for Channel 1 solution with optional jumper resistors. The LTM4634 data and Channel 2, 0.8V to 13.5V for Channel 3. Derating is sheet must be read in conjunction with this demo manual necessary for certain V , V , frequency and thermal prior to working on or modifying demo circuit DC2121A. IN OUT conditions. The DC2121A offers access to the TK/SS pins Design files for this circuit board are available at allowing the user to program output tracking or soft-start DEMO MANUAL DC2121A p s PARAMETER CONDITIONS/NOTES VALUE Input Voltage Range 4.75V to 28V Output Voltages 1.0V, 3.3V, 12.0V 1.5% Maximum Continuous Output Current Derating Is Necessary for Certain Operating Conditions. 5ADC for Ch1 See Data Sheet for Details. 5ADC for Ch2 4ADC for Ch3 Operating Frequency 500kHz Efficiency of Channel 1 V = 12V, V = 1.0V, I = 5A 79.7% See Figure 2 IN OUT1 OUT1 Efficiency of Channel 2 V = 12V, V = 3.3V, I = 5A 91% See Figure 3 IN OUT2 OUT2 Efficiency of Channel 3 V = 24V, V = 12.0V, I = 4A 94.5% See Figure 4 IN OUT3 OUT3 Load Transient of Channel 1 V = 12V, V = 1.0V, I = 0A to 2.5A See Figure 5 IN OUT1 STEP Load Transient of Channel 2 V = 12V, V = 3.3V, I = 0A to 2.5A See Figure 6 IN OUT2 STEP Load Transient of Channel 3 V = 24V, V = 12.0V, I = 0A to 2A See Figure 7 IN OUT3 STEP Quick s p D Demonstration circuit DC2121A is an easy way to evaluate adjustable pulse signal between IOSTEP CLK and GND the performance of the LTM4634. Please refer to Figure test points. The pulse amplitude sets the load step cur- 1 for proper measurement equipment setup and follow rent amplitude. Keep the pulse width short (<1ms) and the procedure below. pulse duty cycle low (<5%) to limit the thermal stress on the load transient circuit. Switch the jumper resistors 1. Place jumpers in the following positions for a typical R30, R31 or R34 (on the backside of boards) to apply application load transient on channel 1, channel 2, or channel 3 RUN1 RUN2 RUN3 MODE correspondingly. ON ON ON CCM 6. (Optional) LTM4634 can be synchronized to an external clock signal. Place the JP4 jumper on EXT CLK and 2. With power off, connect the input power supply, loads apply a clock signal (0V to 5V, square wave) on the and meters as shown in Figure 1. Preset the load to 0A CLKIN test point. and V supply to 24V. IN 7. (Optional) The outputs of LTM4634 can track another 3. Turn on the power supply at the input. The output supply. If tracking external voltage is selected, the cor- voltage of channel 1 should be 1.0V 1.5% (0.985V responding test points, TRACK1, TRACK2, and TRACK3, to 1.015V). The output voltage of channel 2 should be need to be connected to a valid voltage signal. 3.3V 1.5% (3.25V to 3.349V). The output voltage of channel 3 should be 12.0V 1.5% (11.82V to 12.18V). 8. (Optional) Channel 1 and 2 can be connected in paral- lel for a 10A polyphase operation on DC2121A. Install 4. Vary the input voltage and adjust the load current of 0 resistors on R32, R33, R35, R36 and remove R15. channel 1 and channel 2 from 0A to 5A and channel 3 Output voltage is set by R4 based on equation: from 0A to 4A. Observe the output voltage regulation, ripple voltage, efficiency, and other parameters. 60.4k 2 5. (Optional) For optional load transient test, apply an V =0.8V +1 OUT R4 dc2121af 2 ure roce tart ummary erformance