LM2576-12 MOTOROLA [Motorola, Inc], LM2576-12 Datasheet - Page 21

• Manufacturer Part Number: LM2576-12
• Description: Easy Switcher 3.0A Step-Down Voltage Regulator
• Manufacturer: MOTOROLA [Motorola, Inc]

predetermined threshold level with respect to the ground
Pin 3, which is determined by the following expression:
current:
where t on
MOTOROLA ANALOG IC DEVICE DATA
The following formula is used to obtain the peak inductor
1N5242B
Figure 32. Undervoltage Lockout Circuit for
40 V Max
Unregulated
DC Input
I
+V in
NOTE: This picture does not show the complete circuit.
10 k
10 k
peak
V
R2
Z1
R1
100 F
th
+
C in
[
[
V
47 k
V
R3
in
Z1
I
Load
+V in
|V
)
)
Buck Converter
Q1
2N3904
1
O
Figure 34. 1.2 to 35 V Adjustable 3.0 A Power Supply with Low Output Ripple
|V
|
(V
1.0
O
3
V
in
|
LM2574–Adj
in
)
x 1.0
Gnd
C in
100 F
)
+V in
R2
R1
f osc
1
|V
O
, and f osc
V
5
5
|)
BE
LM2576–XX
V th 13 V
ON/OFF
)
ON/OFF
(Q1)
V
in
2
4
Feedback
Output
2L 1
3
x t on
+
Gnd
52 kHz.
D1
1N5822
LM2576
150 H
L1
conditions, the worst case occurs when V in is minimal.
Adjustable Output, Low–Ripple Power Supply
features an adjustable output voltage is shown in Figure 34.
input voltage ranges from roughly 3.0 V to 40 V. In order to
achieve a 10 or more times reduction of output ripple, an
additional L–C filter is included in this circuit.
1N5242B
Under normal continuous inductor current operating
A 3.0 A output current capability power supply that
This regulator delivers 3.0 A into 1.2 V to 35 V output. The
C out
2200 F
+V in
Figure 33. Undervoltage Lockout Circuit for
15 k
15 k
R2
Z1
R1
NOTE: This picture does not show the complete circuit.
47 k
R3
Buck–Boost Converter
R2
50 k
R1
1.21 k
Q1
2N3904
Optional Output
C in
100 F
+V in
Ripple Filter
20 H
100 F
L2
1
C1
5
LM2576–XX
ON/OFF
1.2 to 35 V @ 3.0 A
Voltage
Output
3
Gnd
V th 13 V
V out
21