rev.
page 3 of 4
date 04/2008
PART NUMBER: V78XX-1000 series
DESCRIPTION: DC switching regulator, non-isolated
TYPICAL APPLICATION CIRCUIT
Vout
Vin
1
3
V78XX-1000
2
C2
100μF/25V
C1
22μF/50V
GND
INPUT CAPACITOR (C1):
A low ESR capacitor is recommended to keep the noise at the converter to a minimum.
Ceramic capacitors are preferred but tantalum or low ESR electrolytic capacitors may
also suffice. Place C1 as close as possible to pins 1 & 2.
OUTPUT CAPACITOR (C2):
A 100μF/25V electrolytic capacitor is recommended.
NOT FOR PARALLEL OPERATION
This converter is not designed for parallel operation with another to increase output
power.
TEST CIRCUIT
FOR EFFICIENCY & RIPPLE GRAPHS (PAGE4)
Electronic
Load
Current
Meter
Current
Meter
+Vout
+
-
+Vin
30cm, 18AWG
Twisted
DC/DC
Converter
A
B
Cin
Voltage
Meter
Voltage
Meter
DC Power
Source
20MHz
Oscilloscope
Cout
GND
0V
+
A
+
A
A
B
C01
C02
1. Cin = 10μF / 50V for 500mA and 22μF / 50V for 1A, Cout = 100μF / 16V.
2. C01 = 10μF / 50V Electrolytic, C02 = 0.1μF / 50V Ceramic.
3. All points labeled A refer to one junction.
B
B
-
4. All points labeled B refer to one junction.
5. Use a short ground loop for probing. Do not use a wired ground clip.
th
20050 SW 112 Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
CUI [ CUI INC ]
