DEMO MANUAL DC2268A-F LTM4630A Dual 18A or Single 36A Module Regulator DESCRIPTION Demonstration circuit 2268A-F is a high efficiency, high through the TRACK/SS pin. Remote output voltage sens- density, dual 8A, switch mode step-down power supply ing is available for improved output voltage regulation on a compact 1.5 1.2 PCB. It features the LTM 4630A at the load point. An optional input inductor L1 reduces Module regulator. The input voltage is from 4.5V to the EMI noise for noise sensitive applications. DC2268A 15V. The output voltage is programmable from 0.6V to can be easily inserted to an edge connector for testing 5.3V. DC2268A-F can deliver up to 18A maximum in each and debugging. These features and the availability of the channel. As explained in the data sheet, output current LTM4630A in a compact 16mm 16mm 4.41mm LGA derating is necessary for certain V , V , and thermal package make it ideal for use in many high-density point- IN OUT conditions. The board operates in continuous conduc- of-load regulation applications. The LTM4630A data sheet tion mode in heavy load conditions. For high efficiency must be read in conjunction with this demo manual for at low load currents, the resistor jumper (R1/R2) selects working on or modifying the DC2268A-F. pulse-skipping mode for noise sensitive applications or Design files for this circuit board are available. Burst-Mode in less noise sensitive applications. Two out- All registered trademarks and trademarks are the property of their respective owners. puts can be connected in parallel for a single 36A output solution with optional jumper resistors. The board allows the user to program how its output ramps up and down BOARD PHOTO Figure1. LTM4630A/DC2268A-F Demo Board Rev.0 1DEMO MANUAL DC2268A-F PERFORMANCE SUMMARY Specifications are at T = 25C A Table1. PARAMETER CONDITIONS VALUE Input Voltage Range 4.5V ~ 15V Output Voltage V V = 4.5~15V, I = 0A ~18A 3.3V 1.5% OUT1 IN OUT1 Output Voltage V V = 4.5~15V, I = 0A ~18A 2.5V 1.5% OUT2 IN OUT2 Per-Channel Maximum Continuous Output Current De-rating is necessary for certain V , V and thermal conditions 18A (per channel) IN OUT Default Operating Frequency 600kHz Resistor Programmable Frequency Range 250kHz to 780kHz External Clock Sync. Frequency Range 400kHz to 780kHz Efficiency of Channel 1 V = 12V, V = 3.3V, I = 18A, f = 600kHz 93.0%, see Figure3 IN OUT1 OUT1 SW Efficiency of Channel 2 V = 12V, V = 2.5V, I = 18A, f = 600kHz 91.1%, see Figure4 IN OUT2 OUT2 SW Load Transient of Channel 1 V = 12V, V = 3.3V, I = 9A ~ 13.5A V = 139mV, see Figure5 IN OUT1 STEP OPP Load Transient of Channel 2 V = 12V, V = 2.5V, I = 9A ~ 13.5A V = 102mV, see Figure6 IN OUT2 STEP OPP QUICK START PROCEDURE DC2268A-F is easy to set up to evaluate the performance 4. Once the proper output voltage is established, adjust of the LTM4630A. It can be easily inserted to an edge the load within the operating range and observe the connector (SAMTEC MEC2-20-01-L-DV--TR) for testing output voltage regulation, output voltage ripple, effi- and debugging. Please refer to Figure 2 for proper mea- ciency and other parameters. Output ripple should be surement setup and follow the procedure below: measured at C and C . o3 o4 1. Pull up the RUN1(J1 Pin 22) and RUN2(J1 Pin 24) 5. (Optional) LTM4630A can be synchronized to an exter- between 1.4V to 5V or leave them floating. nal clock signal. Remove R2 and apply a clock signal (0V~5V, square wave) to MODE-PLLIN pin. 2. With power off, connect the input power supply, load and meters as shown in Figure2. Preset the load to 0A 6. (Optional) LTM4630A can be configured for a 2-phase and V supply to 12V. single output at up to 36A on DC2268A-F. Install 0 IN resistors on R26, R27, R28, R29, R32, and remove 3. Turn on the power supply at the input. The output volt- R14, R18 R30. Output voltage is set by R7 based on age in channel 1 should be 3.3V 1.5% (3.2505V ~ equation V = 0.6V (1 + 60.4k/R7). OUT 3.3495V) and the output voltage in channel 2 should be 2.5V 1.5% (2.4625V ~ 1.5375V), Rev.0 2