DEMO MANUAL DC2479A-B LTM4650EY-1 Dual Phase Single 50A DC/DC Module Regulator DESCRIPTION Demonstration circuit 2479A-B features the LTM 4650EY-1, These features and the availability of the LTM4650EY-1 the high efficiency, high density, dual 25A, single 50A in a compact 16mm 16mm 5.01mm BGA package switch mode step-down power module regulator. The make it ideal for use in many high-density point-of-load input voltage is from 4.5V to 15V. The output voltage is applications. The LTM4650-1 data sheet must be read programmable from 0.6V to 1.8V. DC2479A-B is configured in conjunction with this demo manual for working on or as dual-phase, single-output, which can deliver up to 50A modifying the demo circuit DC2479A-B. maximum. The board designs with minimum components Design files for this circuit board are available at to demonstrate this high efficiency, high density Module. DEMO MANUAL DC2479A-B PERFORMANCE SUMMARY Specifications are at T = 25C A PARAMETER CONDITIONS/NOTES VALUE Input Voltage Range 4.5V ~ 15V Output Voltage V V = 4.5~15V, I = 0~50A 1.0V 1.5% (0.985V ~ 1.015V) OUT IN OUT Maximum Continuous Output Current De-Rating is Necessary for Certain V , V and Thermal Conditions, 50A IN OUT See Data Sheet for Detail. Default Operating Frequency 500kHz Efficiency V = 12V, V = 1.0V, I = 50A, f = 500 kHz 86.6%, See Figure 4 IN OUT OUT SW Load Transient V = 12V, V = 1.0V, I = 25A to 37.5A < 60mV , See Figure 5 IN OUT STEP P-P QUICK START PROCEDURE Demonstration circuit DC2479A-B is easy to set up to voltage regulation, output voltage ripple, efficiency and evaluate the performance of the LTM4650EY-1. Please other parameters. Output ripple can be measured at J6 refer to Figure 1 for proper measurement setup and follow with BNC cables. the procedure below: 4. (Optional) For optional load transient test, apply an 1. With power off, connect the input power supply, load adjustable pulse signal between IOSTEP CLK and and meters as shown in Figure 2. Preset the load to 0A GND test point. Pulse amplitude (3V~3.5V) sets the and V supply to 12V. load step current amplitude. The output transient current IN can be monitored at the BNC connector J5 (10mV/A). 2. Turn on the power supply at the input. The output volt- The pulse signal should have very small duty cycle age should be 1.0V 1.5% (0.985V~1.015V). (< 10%) to limit the thermal stress on the transient 3. Once the proper output voltage is established, adjust the load circuit. load within the operating range and observe the output dc2479abf 2