DEMO MANUAL DC1245A LTM4616 Dual 2.7V , 8A Step-Down IN(MIN) Module Regulator Description Demonstration circuit 1245A features the LTM 4616, the frequency harmonics but also to parallel the two channels high efficiency, high density, dual output switch mode of LTM4616 or even multiple LTM4616s and LTM4608s to power module. The rated load current is 8A for each chan- provide higher output currents. The LTM4616 data sheet nel, while derating is necessary for certain V , V , and must be read in conjunction with this demo manual prior IN OUT thermal conditions. By applying a clock signal to the CLKIN to working on or modifying demo circuit DC1245A. pin, the modules switching frequency may be synchronized Design files for this circuit board are available at from 0.75MHz to 2.25MHz. The same clock frequency is DEMO MANUAL DC1245A q Uick st Art proce DU Demonstration circuit 1245A is an easy way to evaluate 4. Once the proper output voltage is established, adjust the performance of the LTM4616. Please refer to Figure1 the load within the operating range and observe the for proper measurement equipment setup and follow the output voltage regulation, ripple voltage, efficiency and procedure below: other parameters. To measure input and output ripple, please refer to Figure 2 for proper setup. 1. Place jumpers in the following positions for a typical 1.8V and 1.2V application: 5. To synchronize channel 1 to an external clock, please OUT OUT apply the desired clock signal to CLKIN and SGND1. PHMODE2 MARGINING2 RUN2 MARGINING1 The external clock signal should have amplitude of at 2PH NO ON NO least 2V but less than V . IN TRACK1 PHMODE1 MODE RUN1 6. V can track another supply connected at TP20 as OUT1 DISABLED 2PH BURST ON determined by resistors R6 and R17. V is set up OUT2 to track V in a manner determined by resistors OUT1 2. With power off, connect the input power supply, load R15 and R16. By default both resistor pairs have been and meters as shown in Figure 1. Preset the load to 0A selected to support coincident tracking. Please refer to and V supply within the 2.7V to 5.5V operating range. IN Figure 6 for reference. 3. Turn on the power at the input. The output voltage at + VO1 and VO1 should be 1.8V 2% and the voltage + at VO2 and VO2 should be 1.2V 2%. INPUT OR OUTPUT CAPACITOR Figure 2. Proper Scope Probe Placement for Measuring Input or Output Ripple Overall Efficiency vs Load Current 95 V = 3.3V, V = 1.8V, V = 1.2V IN O1 O2 90 85 80 75 V = 5V, V = 1.8V, V = 1.2V IN O1 O2 70 65 60 55 50 45 40 35 0 2 4 6 8 10 LOAD CURRENT FOR EACH CHANNEL (A) dc1245a F03 Figure 3. Measured Overall Supply Efficiency with Different V IN Figure 1. Test Setup of DC1245A dc1245afa 2 EFFICIENCY (%) re