si-3120c Sanken Electric Co., Ltd., si-3120c Datasheet - Page 5

• Manufacturer Part Number: si-3120c
• Description: 5-terminal, Full-mold, Low Dropout Voltage Linear Regulator Ics
• Manufacturer: Sanken Electric Co., Ltd.

GSI-3000C Series
1. Variable output voltage with a single external resistor
The output voltage may be increased by inserting resistor R
terminals No.4 (sensing terminal) and No.3 (output terminal). The cur-
rent I
therefore the adjusted output voltage V
However, the internal resistor (between terminals No. 4 and No.1) is a
semiconductor resistor, which has approximately thermal characteris-
tics of +0.2%/°C.
It is important to keep the thermal characteristics in mind when adjust-
ing the output voltage.
2. Variable output voltage with two external resistors
The output voltage may be increased by inserting resistors R
tween terminals No.4 (sensing terminal) and No.3 (output terminal) and
R
The current I
0.43mA (typ.)) so the thermal characteristics may be improved com-
pared to the method shown in 1 by setting the external current I
approximately 5 times the value of I
The adjusted output voltage V
The value of the external resistors may be obtained as follows:
*V
Note: In the SI-3000C series, the output voltage increase can be ad-
40
External Variable Output Voltage Circuit
EX2
04
S: Stability coefficient of I
GND
: Output voltage of SI-3000C series
V
REX
GND
between terminals No.4 and No.1 (ground terminal).
IN
V
justed as mentioned above. However, when the rise is set to ap-
proximately 10V compared to output voltage V
output current may not be obtained due to the S.O.A. protection
circuit in the SI-3000C series.
IN
flowing into terminal No.4 is 1mA (typ.)(SI-3033C:0.43mA (typ.)),
V
V
I
R
REX1
O
O
EX1
+
=V
=V
4IN
+
47µF
=
=S•I
04
04
47µF
flowing into terminal No.4 is 1mA (typ.)(SI-3033C:
+I
+R
OPEN
V
S•I
4IN
REX
OPEN
O
EX1
-V
4IN
•R
•I
04
4IN
5
2
REX1
EX
5
2
(may be set to any value)
,
OUT
R
SI-3000C
*V
EX2
SI-3000C
04
1
in this case is:
: output voltage of SI-3000C series
=
1
4IN
(S-1)•I
(stability coefficient S=5).
OUT
V
04
is:
3
4
4IN
3
4
I
REX
I
REX1
I
4IN
V
04
R
04
V
EX
R
R
, the necessary
04
EX1
EX2
+
EX
47µF
+
between
47µF
EX1
REX1
V
GND
O
V
GND
be-
O
at
35
30
25
20
15
10
35
30
25
20
15
10
5
0
5
0
V
V
IN
IN
=V
=V
O
2
O
+1V
External Resistor R
External Resistor R
+1V
4
1.0
6
EX1
EX
(kΩ)
(kΩ)
8
2.0
10