LM2576 Series
Test Circuit and Layout Guidelines
As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage
transients which can cause problems. For minimal 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. When using the Adjustable version,
physically locate the programming resistors near the regulator, to keep the sensitive feedback wiring short.
Fixed Output Voltage Versions (Figure 2a)
FEEDBACK
+VIN
LM2576HV-
FIXED OUTPUT
4
L1
V
OUT
OUTPUT
1
2
100
H
L
O
V
IN
100
GN
F
+
D
3
C
OUT
5
+
ON/OFF
UNREGULATED
DC INPUT
A
D
1000
MBR360
CIN — 100µF, 75V, Aluminum Electrolytic
COUT —1000µF, 25V, Aluminum Electrolytic
D1 — Schottky, MBR360
L1 — 100µH, Pulse Eng. PE-92108
R1 — 2k, 0.1%
R2 — 6.12k, 0.1%
Adjustable Output Voltage Version (Figure 2b)
FEEDBACK
+VIN
LM2576HV-
V
5.00V
OUT
4
L1
ADJ
OUTPUT
1
2
100
L
100
F
7V -60V
UNREGULATED
DC INPUT
R2
R1
5
+
GND
3
COUT
O
A
D
ON/OFF
IN
C
1000
MBR360
R
VOUT
V
REF 1(
+
2
)
VOUT
VREF
−
R2
R1
(
)1
where VREF = 1.23V, R1 between 1k and 5k
REV No:01-060813
TIGER ELECTRONICS CO.,LTD
8
TGS [ Tiger Electronic Co.,Ltd ]
