1. Application Circuit
In the following explain only the positive regulator unless otherwise specified. However they can apply to the
negative voltage regulator by easy change.
Positive/Negative Voltage Supply
78 series
+Vin
IN
GND
0.33uF
D1
0.1uF
OUT
+Vo
Note : In the above positive and negative
power supply application, D1 and D2
should be connected. If D1 and D2
are not connected, either of positive
or negative power supply circuit may
not turns on.
COM
0.33uF
COM
-Vin
IN
79 series
OUT
D2
0.1uF
-Vo
2. Note in Application Circuit
(1)
If the higher voltage (above the rated value) or lower voltage (GND-0.5V) is supplied to the input
terminals, the IC may be destroyed. To avoid such a case, a zener diode or other parts of the surge
supressor should be connected as shown below.
L
R
Vin
1
IN
OUT
3
Vo
Vin
1
IN
OUT
3
Vo
GND
GND
+
Ze ner Diode
Capacitor
+
Diode
Capacitor
(2)
If the higher voltage than the input terminal is supplied to the output terminal, the IC may be
destroyed. To avoid input terminal short to the GND or the stored voltage in the capacitor back to the
output terminal, by the large value capacitor connecting to the output terminal application, the SBD
should be required as shown below;
DIODE
2
2
Vin
1
IN
OUT
3
Vo
* In case of negative voltage regulator, reverse the SBD and capacitor direction.
GND
2
+
Capacitor
Page 7 of 10
MICRO-ELECTRONICS [ Micro Electronics ]
