DEMO MANUAL DC2141A LTM4647 30A DC/DC Step-Down Module Regulator DESCRIPTION Demonstration circuit 2141A features the LTM 4647EY, less noise sensitive applications. The MODE PLLIN pin a 30A high efficiency, switch mode step-down power also allows the LTM4647 to synchronize to an external Module regulator. The input voltage range is from 6V to clock signal (between 400kHz and 800kHz). DC2141A 15V. To use DC2141A for input voltage range from 4.7V to has the option of choosing both internal and external 6V, connect INTVCC to SVIN (change R22 from OPT to 0), compensation circuit for LTM4647. Tying the PHASMD DRVCC to VIN (change R21 from 0 to OPT, R28 from OPT pin to different voltage generates certain phase difference to 0). The output voltage range is 0.6V to 1.8V. Derating between MODE PLLIN and CLKOUT. The LTM4647 data is necessary for certain VIN, VOUT, frequency and thermal sheet must be read in conjunction with this demo manual conditions. The DC2141A offers the TRK/SS pin allowing prior to working on or modifying demo circuit DC2141A. the user to program output tracking or soft-start period. The Design files for this circuit board are available at board operates in continuous conduction mode in heavy DEMO MANUAL DC2141A PERFORMANCE SUMMARY Specifications are at T = 25C A PARAMETER CONDITIONS MIN TYP MAX UNITS Input Voltage Range 6 15 V Output Voltages R = 90.9k 1.0 1.0% V FB Maximum Continuous Output Current Derating Is Necessary for Certain Operating Conditions. 30 ADC See Data Sheet for Details Operating Frequency R = 47.5k 600 kHz FREQ Efficiency V = 12V, V = 1.0V, I = 30A 86.2 Figure 2 % IN OUT OUT Load Transient V = 12V, V = 1.0V, I = 5A to 20A 153 Figure 3 mV IN OUT STEP QUICK START PROCEDURE Demonstration circuit 2141A is an easy way to evaluate the 4. Vary the input voltage from 6V to 15V and adjust the performance of the LTM4647EY. Please refer to Figure 1 load current from 0A to 30A. Observe the output volt- for proper measurement equipment setup and follow the age regulation, ripple voltage, efficiency, and other procedure below: parameters. 1. Place jumpers in the following positions for a typical 5. (Optional) For optional load transient test, apply an application: adjustable pulse signal between IOSTEP CLK and GND test points. The pulse amplitude sets the load step cur- MODE RUN rent amplitude. Keep the pulse width short (<1ms) and CCM ON pulse duty cycle low (<5%) to limit the thermal stress 2. With power off, connect the input power supply, load on the load transient circuit. and meters as shown in Figure 1. Preset the load to 0A 6. (Optional) LTM4647 can be synchronized to an external and V supply to 12V. IN clock signal. Place the JP1 jumper on EXT CLK and 3. Turn on the power supply at the input. The output volt- apply a clock signal (0V to 5V, square wave) on the age should be 1.0V 1.0% (0.99V to 1.01V). MODE PLLIN test point. dc2141af 2