User Guide for ANALOG DEVICES models including: DC1043A-A, DC1043A-C, LTM4601EV Evaluation Kit, LTM4601EV, Evaluation Kit
DC1043A-C Analog Devices, Inc. - RADIOMAG GmbH
File Info : application/pdf, 7 Pages, 1.33MB
DocumentDocumentQUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE LTM4601EV DESCRIPTION Demonstration circuit DC1043A-A features the LTM®4601EV and LTM4601-1EV, the high efficiency, high density switch mode step-down power modules. The input voltage range is from 5.0V to 20V. The output voltage is programmable from 0.6V to 3.3V; refer to step down ratio curve in the LTM4601 datasheet. The rated load current is 20A, while de-rating is necessary for certain VIN, VOUT, and thermal conditions. 24A load current can be achieved by applying forced airflow convection or attaching heatsinks. Master module U1 provides differential remote sensing to accurately regulate output voltage independent of load current. Integrated input and output filters enable a simple PCB layout. Only bulk input and output capacitors are needed externally. The DC1043A-A has onboard 180 degree interleaving clock generator. The default clock frequency is 750 KHz. The LTM4601 allows the user to program output ramp-up and rampdown through the TRACK/SS pin. The output can be set to coincidentally or ratiometrically track with another supply's output. Margining function is provided for the user who wants to stress their system by varying supply voltages during testing; refer to datasheet for functional diagram. If desired, slave unit U2 could be substituted by LTM4601-1EV. Design files for this circuit board are available. Call the LTC Factory. , LTC and LT are registered trademarks of Linear Technology Corporation. Table 1. Performance Summary (TA = 25°C) PARAMETER CONDITION Minimum Input Voltage Maximum Input Voltage Output Voltage VOUT Maximum Continuous Output Current Jumper selectable (open for 0.6V) De-rating is necessary for certain VIN, VOUT, and thermal conditions Default Operating Frequency Efficiency Load Transient VIN=12V, VOUT =1.5V, IOUT =20A VIN=12V, VOUT =1.5V VALUE 5V 20V 1.2V, 1.5V, 1.8V, 2.5V, 3.3V 20ADC 750kHz 83.2%, See Figure 3 See Figure 4 QUICK START PROCEDURE Demonstration circuit DC1043A-A is easy to set up to evaluate the performance of the LTM4601EV. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. Place jumpers in the following positions for a typical 1.5VOUT application: Vout Select RUN MARG0 MARG1 1.5V ON LO LO Downloaded from Arrow.com. 2. With power off, connect the input power supply, load and meters as shown in Figure 1. Preset the load to 0A and Vin supply to be less than 20V. 3. Turn on the power at the input. The output voltage should be 1.5V ± 2%. 4. Once the proper output voltage is established, adjust the load within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other pa- 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE rameters. Output ripple should be measured across the output capacitors. 5. For optional load transient test, apply adjustable pulse signal between IOSTEP CLK and GND pins. Pulse amplitude sets the current step. The pulse signal should have very small duty cycle (<15%) to limit the thermal stress on the transient load circuit. The output transient current can be monitored at BNC connector J5 (25mV/10A). 6. For Margining function test, place jumper MARG0 and MARG1 in the configurations shown in the following table, measure the output voltage at Vo+ and Vo-. MARG1 LO LO HI HI MARG0 LO HI LO HI Vout 0 +5% -5% 0 Figure 1. Test Setup of DC1043A-A 2 Downloaded from Arrow.com. QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE + Figure 2. Scope Probe Placements for Measuring Input or Output Ripple. Efficiency vs. Load Current W/ 12Vin 95% 90% 85% 80% 1.2Vout 75% 1.5Vout 1.8Vout 70% 2.5Vout 3.3Vout 65% 0 4 8 12 16 20 24 Load Current (A) Efficiency vs. Load Current W/ 20Vin 90% 85% 80% 75% 1.2Vout 1.5Vout 70% 1.8Vout 65% 2.5Vout 3.3Vout 60% 0 4 8 12 16 20 24 Load Current (A) Figure 3. Measured Supply Efficiency with Different VIN and VOUT Efficiency (%) Efficiency (%) 3 Downloaded from Arrow.com. QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE Vout (AC) 50mV/DIV Istep 8A/DIV Vin = 12V Vout =1.5V 5A to 15A LOAD STEP (50%) Cout = 2 X 22uF ceramic, 4X100uF ceramic; C12 = 47pF Figure 4. Measured Load Transient Response (5-15A Step) Vo = 1.5V@20A Vin = 20V Figure 5. Measured Thermal Performance 4 Downloaded from Arrow.com. QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE 5 Downloaded from Arrow.com. QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE 6 Downloaded from Arrow.com. QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1043A-A HIGH DENSITY POWER MODULE 7 Downloaded from Arrow.com.