Demonstration circuit DC1663A features the LTM®4628EV,
the high efficiency, high density, dual 8A output, switch
mode step-down power module. The input voltage is
from 4.5V to 26.5V. The output voltage is programmable
from 0.6V to 5.5V. Output current derating is necessary
for certain VIN, VOUT, and thermal conditions. The board
operates in continuous conduction mode in heavy load
conditions. For high efficiency at low load currents, the
MODE jumper (JP1) selects pulse-skipping mode for
noise sensitive applications or Burst Mode® operation
in less noise sensitive applications. The DC1663A sets
the LTM4628EV default switching frequency to 400kHz;
however the frequency is resistor programmable from
250kHz up to 780kHz. An internal phase-lock loop allows
the module to be synchronized to an external clock. The
board allows the user to program how its output ramps
up and down through the TRACK/SS pin. The output can
be set up to either coincidentally or ratio metrically track
with another supply’s output. Remote output voltage sensing is available for improved output voltage regulation at
the load point. These features and the availability of the
LTM4628EV in a compact 15mm × 15mm × 4.32mm LGA
package make it ideal for use in many high density point
of load regulation applications. The LTM4628 datasheet
must be read in conjunction with this demo manual for
working on or modifying the demo circuit DC1663A.
