CUI Inc │ SERIES: V78W-500 │ DESCRIPTION: DC-DC CONVERTER
date 09/28/2011 │ page 4 of 5
TYPICAL APPLICATION CIRCUIT
APPLICATION EXAMPLE
High voltage input, multiple outputs, with greater load
1
3
V78W-500(R)
+Vout
GND
Reverse protection
+Vin
1
3
V7812W-500(R)
+12V/100mA
+5V/850mA
GND
+Vin
2
C1
2
V7805W-500(R)
C1
C2
ꢀꢁ
GND
F
GND
1. The regulator proposed to establish the input voltage by
soft-start, no plug and play, if the input voltage changes from
low voltage to high voltage abruptly, the regulator might be
damaged.
1. The input current amount of the back-grade regulator and
the pre-class load should be less than or equal the max load
current of the pre-class regulator.
2. If the applications is high-voltage input, the regulator
must add an external capacitor C1(≤47ꢀF/100V) to prevent
voltage spikes caused by damage to the module.
2. If further filtering is required, please add components
as per the above circuit (We recommend not to add
components), if request, please make sure the capacitors C1
≤47ꢀF, C2≤10ꢀF more close to the back-grade regulator.
3. No parallel connection.
MODULES PROTECT RECOMMENDED CIRCUIT
DERATING CURVE
Temperature Derating Graph
1
3
+Vin
V78W-500(R)
+Vout
GND
2
GND
+Vin
Vout=
+Vout-
0.3V
3
1
V78W-500(R)
Schottky Diode
2
Operating Temp.( C )
GND
GND
EMC RECOMMENDED CIRCUIT
0.5mH-2mH
+Vout 3
1
+Vin
Vin
GND
2
RL
270 F-470 F
ND
1.0 F-3.3 F
0.68 F-2.2 F
0.5mH-2mH
cui.com
CUI [ CUI INC ]
