Power Management
A A
MICROELECTRONICS
GM7230
3A STEP-DOWN VOLTAGE REGULATOR
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.
Figure 1(a). Fixed Output Voltage Versions
Feedback
4
GM 7230-
+V
IN
FIXED OUTPUT
L1
1
V
Output
OUT
2
GND
3
ON/OFF 5
I
V
IN
+
+
Current
meter
Unregulated
DC Input
D1
C
IN
C
OUT
K1
C
- 470 µF, 50V,Aluminum Electrolytic
IN
C
- 220 µF, 25V,Aluminum Electrolytic
OUT
D1 - 5A, 40V Schottky
L1 - 68 µH, 3L Electronic Corp. TC-680M-3A-5026
6
GAMMA [ GAMMA MICROELECTRONICS INC. ]
