gm7130-atb5t Gamma Microelectronics, gm7130-atb5t Datasheet - Page 7

• Manufacturer Part Number: gm7130-atb5t
• Description: Gm7130 3a Step-down Voltage Switching Regulators
• Manufacturer: Gamma Microelectronics

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 Gm7130, to keep the
sensitive feedback wiring short.
Unregulated
Unregulated
DC Input
DC Input
7V - 40V
MICROELECTRONICS
V
A
IN
Figure 1(b). Adjustable Output Voltage Versions
+
+
100 µF
A
C
100 µF
IN
+V
C
C
C
D1 - Schottky, MBR360
L1 - 100 µH, 3L Electronic Corp. TC-101M-3.0A-6826
R1 - 2k, 0.1%
R2 - 6.12k, 0.1%
GND 3
where V
IN
IN
IN
OUT
1
Figure 1(a). Fixed Output Voltage Versions
+V
- 100 µF, 75V, Aluminum Electrolytic
IN
GND 3
1
- 680 µF, 25V, Aluminum Electrolytic
GM7130-ADJ
REF
FIXED OUTPUT
V
ON/ OFF
= 1.23V, R1 between 1k and 5k.
OUT
R2 = R1 (
GM 7130-
3A STEP-DOWN VOLTAGE SWITCHING REGULATORS
= V
REF
ON/OFF
5
Power Management
( 1 +
V
V
OUT
REF
Feedback
4
Output
2
R2
R1
-1)
5
)
Output
Feedback
4
2
D1
MBR360
100 µH
L1
D1
+
C
680 µF
OUT
100 µH
L1
680 µF
+
C
OUT
GM7130
R2
R1
V
OUT
=5.0V
V
OUT
O
D
L
A
O
A
D
L
7