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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 the 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
GM7230
I
Current
meter
K1