TC2574 Datasheet, PDF (5/25 Pages) TelCom Semiconductor, Inc – 0.5A Step-Down Switching Regulator

0.5A Step-Down Switching Regulator
TC2574
7.0 – 40V
Unregulated
DC Input
CIN
22µF
+VIN
+⁵
2
Feedback
1
TC2574
Output
7
Sig 4 PWR 3 ON/OFF
GND GND
L1
330µH
D1 ^COUT
220µF
5.0V Regulated
Output 0.5A Load
Figure 1. Block Diagram and Typical Application: Fixed Output Versions
Test CIrcuit and Layout Guidelines
7.0 – 40V
Unregulated
DC Input
VIN
5
+ _CIN ⁴
22µF
TC2574
Fixed Output
PWR ² Sig 3
GND GND
1
Output
7
ON/OFF
L1
330µH
D1
1N5819
COUT ⁺
220µF
VOUT
Load
CIN - 22µF, 60V, Aluminum Electrolytic
COUT - 220µF, 25V, Aluminum Electrolytic
D1 - Schottky, 1N5819
L1 - 2.0k,0.1%
R2 - 6.12k, 0.1%
Adjustable Output Voltage Versions
7.0 – 40V
Unregulated
DC Input
VIN
5
4
+ _CIN
22µF
TC2574
Adjustable
PWR ² Sig 3
GND GND
1
Output
7
ON/OFF
L1
330µH
D1
+
1N5819
COUT
220µF
VOUT
5.0V
R2
6.12k _Load
R2
6.12k
( ) VOUT = VREF 1.0 + R2
R1
( ) R1= R2 VOUT - 1.0
VREF
Where VREF = 1.23V, R1
between 1.0kΩ and 5.0kΩ
TC2574-1 1/6/00
Figure 2. Test Circuit and Layout Guidelines
5