LM2574-12 Motorola Inc, LM2574-12 Datasheet - Page 22

• Manufacturer Part Number: LM2574-12
• Description: EASY SWITCHERE 0.5 A STEP-DOWN VOLTAGE REGULATOR
• Manufacturer: Motorola Inc

References
+V in
+V in = 7.0 to 40 V
Gnd
22
National Semiconductor LM2574 Data Sheet and Application Note
National Semiconductor LM2594 Data Sheet and Application Note
Marty Brown “Practical Switching Power Supply Design”, Academic Press, Inc., San Diego 1990
Ray Ridley “High Frequency Magnetics Design”, Ridley Engineering, Inc. 1995
The LM2574–ADJ Step–Down Voltage Regulator with 5.0 V @ 0.5 A Output Power Capability Typical
Unregulated
DC Input
Figure 40. PC Board Layout Component Side
Gnd
22 F
+
C1
C1
Figure 39. Schematic Diagram of the 5.0 V @ 0.5 A Step–Down Converter Using the LM2574–ADJ
D1
+V in
5
NOTE: Not to scale.
LM2574
4
U1
(An additional LC filter is included to achieve low output ripple voltage)
Pwr
Gnd
L1
LM2574–ADJ
2
R1 R2
Application With Through–Hole PC Board Layout
Sig
Gnd
3
L1
C2
C1
C2
C3
D1
L2
R1
R2
ON/OFF
+
7
1
Feedback
Output
–
–
–
–
–
–
–
–
L2
22 F, 63 V, Aluminium Electrolytic
220 F, 16 V, Aluminium Electrolytic
100 F, 16 V Aluminium Electrolytic
1.0 A, 40 V, Schottky Rectifier, 1N5819
330 H, RL–1284–330, Renco Electronics
25 H, SFT52501, TDK
2.0 k , 0.1%, 0.25 W
6.12 k , 0.1%, 0.25 W
C3
+
V out
Gnd
D1
1N5819
LM2574
330 H
L1
C2
220 F
Figure 41. PC Board Layout Copper Side
MOTOROLA ANALOG IC DEVICE DATA
R2
6.12 k
R1
2.0 k
NOTE: Not to scale.
Ripple Filter
22 H
100 F
L2
Output
C3
Regulated
Output Filtered
V out = 5.0 V @ 0.5 A
Gnd