DEMO MANUAL DC1453A LTM4619EV: 4.5V-28V, Dual 4A Step-Down Module Regulator DESCRIPTION Demonstration circuit 1453A features the LTM 4619EV, the features include foldback current limiting and overvolt- high input voltage, high ef ciency, high density, dual 4A age protection. Burst Mode operation or pulse skipping step-down power module. Derating is necessary for certain mode can be selected for better light load ef ciency. The V , V , and thermal conditions. The two outputs are LTM4619 data sheet must be read in conjunction with IN OUT interleaved with 180 phase to minimize the input ripple this demo manual for working on or modifying the demo and reduce the input capacitors. A minimum design only circuit 1453A. requires the bulk input and output capacitors and voltage Design les for this circuit board are available at setting resistors. The LTM4619EV features output voltage DEMO MANUAL DC1453A QUICK START PROCEDURE Demonstration circuit 1453A is an easy way to evaluate the 3. Turn on the power at the input. The output voltage + LTM4619. If V is always below 5.5V, stuff a 0 resistor between V and V should be 3.3V 2%, and the IN O1 O1 + at R16. Do not stuff R16 if V is higher than 5.5V. Please voltage between V and V should be 1.8V 2%. IN O2 O2 refer to Figure 1 for proper measurement equipment setup 4. Once the proper output voltage is established, adjust and follow the procedure below: the load within the operating range and observe the 1. Place jumpers in the following positions for a typical output voltage regulation, ripple voltage, ef ciency and 3.3V and 1.8V application: other parameters. MODE/ To measure input and output ripple, please refer to Fig- CLK SEL. RUN1 FREQUENCY TRACK1 RUN2 TRACK2 ure 2 for proper setup. Keep in mind at high switching CCM On 500kHz Soft-Start On Soft-Start frequencies and/or high input voltages, lower output voltage may not regulate properly due to the minimum 2. With power off, preset the loads to 0A and V supply IN on time of the regulator. Refer to the data sheet for more to be less than 28V. Connect the input power supply, details. load and meters as shown in Figure 1. 5. For output voltage tracking during start-up and shut- 0A ~ 4A 0A ~ 4A down, set jumpers JP3 and JP4 to EXT SIGNAL and LOAD + LOAD apply a valid voltage signal to E8 and E10. + 6. To synchronize the switching frequency to an external + + clock set jumper JP2 in the EXT. CLK position and the jumper JP1 in the BURST MODE / EXT. CLK position. Apply a valid clock signal on the CLK SYNC test point. INPUT OR OUTPUT CAPACITOR Figure 2. Proper Scope Probe Placement for Measuring Input or Output Ripple + V IN + Figure 1. Test Setup of DC1453A dc1453af 2 +