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dc2565af

DEMO MANUAL DC2565A

Description

LT8607

42V, 0.75A Micropower Synchronous

Step-Down Regulator

Demonstration Circuit 2565A is a 42V, 0.75A micropower

synchronous step-down regulator featuring the LT®8607.

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 indus-

trial supplies. The LT8607 is a compact, high efficiency,

high speed synchronous monolithic step-down switch-

ing regulator that consumes less than 3μA of quiescent

current when output is regulated at 5V. Top and bottom

power switches, compensation components and other

necessary circuits are inside of the LT8607 to minimize

external components and simplify design.

The SYNC pin on the demo board is grounded by default

SKIPPING position can change the operation mode to

pulse-skipping operation. Once JP1 is on SPREAD SPEC-

EMI spread spectrum operation. To synchronous to an

external clock, move JP1 to SYNC and apply the external

clock to the SYNC turret. Figure 1 shows the efficiency

of the circuit.

L

, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks

of Analog Devices, Inc. All other trademarks are the property of their respective owners.

performance summary

The demo board has an EMI filter installed. The radiated

EMI performances of the board (with EMI filter) are shown

in Figure 2 and Figure 3. The red lines in Figure 2 and

Figure 3 are CISPR25 Class 5 peak limit. To use the EMI

tor 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 LT8607 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 DC2565A.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2565A

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Voltage Range

5.5

42

V

Output Voltage

4.8

5

5.2

V

Maximum Output Current

0.75

A

Switching Frequency

1.85

2

2.15

MHz

EFE

Efficiency at DC

92.4

%