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dc2504af

DEMO MANUAL DC2504A

DESCRIPTION

LT8630 100V, 0.6A

Synchronous Micropower Step-Down

High Efficiency Switching Regulator

Demonstration circuit 2504A is a step-down converter

featuring LT8630. The LT8630 is a monolithic, variable

frequency, current mode synchronous step-down switch-

ing regulator. The demo board is designed for 12V output

from a 13V to 100V input. The wide input range makes it

suitable for regulating power from a variety of sources,

including automotive, industrial systems and telecom

supplies. The power switch, compensation and other

necessary circuits are inside of the LT8630 to minimize

external components and simplify design.

Variable frequency boundary mode switching maximizes

efficiency across the wide input range. Figure 1 shows

the efficiency of the demo board circuit with a 48V input.

The LT8630 will deliver at least 600mA. The maximum

value. Figure 2 shows the max load current at different

input voltages of the demo board.

The LT8630 switching frequency during the boundary

mode operation is determined by the inductor value, input

voltage, output voltage and output current. The frequency

given on Figure 3.

L

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

Technology Corporation. All other trademarks are the property of their respective owners.

PERFORMANCE SUMMARY

The demo board leaves the footprint of an EMI filter on the

backside. Figure 4 shows the radiated EMI performance

of the board when an EMI filter is installed on the board.

The red line in Figure 4 is CISPR25 Class 5 peak limit. The

figure shows that the circuit passes the test with a wide

margin. The conducted EMI can be passed as well with the

right design of the filter. When input EMI filter is required,

The LT8630 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 Demo circuit 2504A. The LT8630 is assembled in a

20-lead TSSOP packages. Proper board layout is essential

for maximum thermal and electrical performance. See the

data sheet sections for details.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2504A

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Supply Range

13

100

V

Output Voltage

11.71

12.11

12.52

V

Max Output Current

0.6

A

Efficiency at DC

91

%