Demonstration circuit 2631A features the LTC7852 in two high output current, high efficiency step down converters each with its own assembly type. The converter for the –A assembly provides two 3-phase outputs of 1.0V / 100A & 1.5V/100A. The –B assembly provides a single 6-phase 1.0V/200A output. Block diagrams are shown in Figure 3. Both converters operate over a 7V to 14V input voltage range at a switching frequency of 400kHz.
The power stage for each phase consists of a 5mm × 5mm DrMOS and 11.3mm × 11.0mm 0.25µH ferrite inductor with a DCR of 0.32mΩ typical. The LTC7852 employs a peak current mode architecture which allows accurate DCR sensing and sharing with sub-mOhm DCR inductors. The LTC7852 provides a three-state compatible PWM output for each DrMOS.
Additional features of the DC2631A include:
- Differential sensing for the output voltages of VOUT1 and VOUT2
- IMON pins to monitor the inductor current of each rail.
- Optional resistors and jumpers to change the phase arrangement for VOUT1 & VOUT2:
- VOUT1: 4ph, VOUT2: 2ph
- VOUT1: 5ph, VOUT2: 1ph
- Note, the default arrangement is: VOUT1: 3ph, VOUT2: 3ph
- Optional resistors and jumpers to parallel VOUT1 & VOUT2.
- RUN, PGOOD, PLLIN and CLKOUT pins