Micrel, Inc.

LM2575

May 2009

6

M9999-051209-B

Test Circuits and Layout Guidelines

LM2575

+

100µF

1

3

GND

5

ON/OFF

2

OU TPU T

4

F E E DBAC K

L1

330µH

+

D1

MBR360

470µF

R2

R1

5.00V

7V - 40V

UN RE GUL A TE D

DC INPUT

L

O

A

D

D1 — Schottky, MBR360

L1 — 330µH, 415-0926 (AIE)

R1 — 1k, 0.01%

R2 — 3.065k, 0.01%

5-pin TO-220 socket—2936 (Loranger Mfg. Co.)

4-pin TO-3 socket—8112-AG7 (Augat Inc.)

LM2575-5.0

+

100µF

1

3

GND

5

ON/OFF

2

OU TPU T

4

F E E DBAC K

L1

330µH

+

D1

MBR360

220µF

5.00V

Note: Pin numbers are for TO-220 Package

7V - 40V

UN RE GUL A TE D

DC INPUT

D1 — Schottky,MBR360

L1 — 330µH, 415-0926 (AIE)

5-pin TO-220 socket — 2936 (Loranger Mfg. Co.)

4-pin TO-3 socket — 8112-AG7 (Augat Inc.)

L

O

A

D

Figure 1.

As in any switching regulator, layout is very important.

Rapidly switching currents associated with wiring

inductance generate voltage transient switch can cause

problems. For minimal stray inductance and ground

loops, the length of the leads indicated by heavy lines

should be kept as short as possible. Single-point

grounding (as indicated) or ground plane construction

should be used for best results.