TEST CIRCUIT AND LAYOUT GUIDELINES

Careful layout is important with any switching regulator. Rapidly switching currents associated with wiring

inductance generate voltage transients which can cause problems. To minimize inductance and ground loops,

the lengths of the leads indicated by heavy lines in Figure 1 below should be kept as short as possible. Single-

point grounding (as indicated in Figure 1) or ground plane construction should be used for best results. When

using the Adjustable version, place the programming resistors as close as possible to Gm7230, to keep the

sensitive feedback wiring short.

V

IN

Unregulated

DC Input

+V

IN

1

+

C

IN

GND 3

5

2

Output

4

Feedback

L1

D1

C

OUT

V

OUT

GM 7230-

FIXED OUTPUT

+

ON/OFF

Figure 1(a). Fixed Output Voltage Versions

C

- 470 µF, 50V, Aluminum Electrolytic

IN

C

- 220 µF, 25V, Aluminum Electrolytic

T

OU

D1 - 5A, 40V Schottky

L1 - 68 µH, 3L Electronic Corp. TC-680M-3A-5026

6

I

Current

meter

K1

A

A

MICROELECTRONICS

GM7230

3A STEP-DOWN VOLTAGE REGULATOR

Power Management