Demonstration circuit 2521A is a 42V, 1.5A micropower
synchronous step-down regulator featuring the LT8608/
LT8608B. There are two assembly versions. DC2521A-A
is for the LT8608 and DC2521A-B is for the LT8608B.
The LT8608/LT8608B is a compact, high efficiency, high
speed synchronous monolithic step-down switching
regulator. Top and bottom power switches, compensation
components and other necessary circuits are inside
of the 2mm × 2mm DFN package to minimize external
components and simplify design. The difference LT8608
and LT8608B is the LT8608 works under low ripple
Burst Mode® operation at light load condition, while the
LT8608B has pulse-skipping mode for light load. Due
to the Burst Mode operation, LT8608 consumes only
1.7μA of quiescent current when output is regulated at
5V. LT8608B has higher quiescent current because of its
pulse-skipping mode operation.
The demo board is designed for 5V output from a 5.5V
to 42V input. The wide input range allows a variety of
input sources, such as automotive batteries and industrial
supplies.
The demo board has an EMI filter installed. To use the EMI
filter, the input should be tied to VEMI, not VIN. An inductor
L2, which is a 0Ω jumper on the board by default
now, can be added in the EMI filter to further reduce the
conducted emission.
The LT8608 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this demo manual
for DC2521A.
