• Highly accurate overcurent protection starting current
SI-3157B : 0.3 to 0.7A (V
IN
=18V)
SI-3025B : 0.3 to 0.7A (When V
IN
=18V, setting V
O
=15.7V)
0.3 to 0.75A (When V
IN
=18V, setting V
O
=11.7V)
• Variable output voltage type (SI-3025B) also available
•
•
•
•
sApplications
• For BS and CS antenna power supplies
• Electronic equipment
sAbsolute
Maximum Ratings
Paarameter
DC Input Voltage
Voltage of Output Control Terminal
DC Output Current
Power Dissipation
Junction Temperature
Ambient Operating Temperature
Storage Temperature
Thermal Resistance (junction to case)
Thermal Resistance (junction to ambient air)
Symbol
V
IN
V
C
I
O
P
D1
P
D2
T
j
T
op
T
stg
R
th(j-c)
R
th(j-a)
Ratings
35
V
IN
0.27
*1
14(With infinite heatsink)
1.5(Without heatsink, stand-alone operation)
–40 to +125
–30 to +100
–40 to +125
7.0
66.7(Without heatsink, stand-alone operation)
Unit
V
V
A
W
W
°C
°C
°C
°C/W
°C/W
(T
a
=25°C)
28
qSI-3000B
Series
sElectrical
Characteristics
Ratings
Parameter
Input Voltage
Output Voltage
(SI-3025B: Reference
Voltage)
Dropout Voltage
Line Regulation
Load Regulation
Temperature Coefficient of Output
Voltage (SI-3025B: Temperature
Coefficient of Reference Voltage)
Ripple Rejection
Quiescent Circuit
Current
Overcurrent Protection
Starting Current
*3,4
Conditions
Control Voltage (Output ON)
Control Voltage (Output OFF)
V
C
Control Current
Control Current
(Output OFF)
Terminal
*5
(Output ON)
V
C.
IH
V
C.
IL
I
C.
IH
Conditions
I
C.
IL
Conditions
V
C
=0.4V
V
C
=2.7V
–0.3
2.0
0.8
20
Symbol
min.
V
IN
V
O
(V
REF
)
Conditions
V
DIF
Conditions
∆V
OLINE
Conditions
∆V
OLOAD
Conditions
∆V
O
/∆T
a
(∆V
REF
/∆T
a
)
Conditions
R
REJ
Conditions
I
q
Conditions
I
S1
Conditions
0.3
V
IN
=18V
I
O
≤0.27A
30
V
IN
=17 to 27V, I
O
=0.2A
120
V
IN
=18V, I
O
=0 to 0.27A
±1.5
V
IN
=18V, I
O
=5mA, T
j
=0 to 100°C
54
V
IN
=18V, f=100 to 120H
Z
3
V
IN
=18V, I
O
=0A
0.7
0.3
0.3
2.0
10
300
90
V
IN
=18V, I
O
=0.2A
0.5
*2
(T
a
=25°C unless otherwise specified)
SI-3157B
typ.
max.
27
*1
15.70
16.48
min.
6
*2,6
2.448
SI-3025B
typ.
max.
27
*1
2.550
V
IN
=V
O
+3V, I
O
=0.2A
0.5
I
O
≤0.27A
10
V
IN
=(V
O
+1) to 27V, I
O
=0.27A
10
V
IN
=V
O
+3V, I
O
=0 to 0.27A
±0.5
V
IN
=V
O
+3V, I
O
=5mA, T
j
=0 to 100°C
54
V
IN
=V
O
+3V, f=100 to 120H
Z
3
V
IN
=V
O
+3V, I
O
=0A
0.75
When V
IN
=18V, setting V
O
=11.7V
0.7
When V
IN
=18V, setting V
O
=15.7V
10
2.652
Unit
V
V
14.92
V
mV
(3025B:
mV/V)
mV
(3025B:
mV/V)
mV/°C
dB
mA
A
V
0.8
20
V
C
=2.7V
–0.3
V
C
=0.4V
µA
mA
*1: V
IN(max)
and I
O(max)
are restricted by the relation P
D(max)
=(V
IN
-V
O
)•I
O
=14(W).
*2: Refer to the dropout voltage.(Refer to Setting DC Input Voltage on page 7.)
*3: I
S
1 is specified at –5(%) drop point of output voltage V
O
on the condition that V
IN
=V
O
+3V, I
O
=0.2A.
*4: A foldback type overcurrent protection circuit is built into the IC regulator. Therefore, avoid using it for the following applications as it may cause
starting errors:
(1) Constant current load (2) Plus/minus power (3) Series power (4) V
O
adjustment by raising ground voltage
*5: Output is ON even when output control terminal V
C
is open. Each input level is equivalent to LS-TTL. Therefore, it may be directly driven by an
LS-TTL circuit.
*6. When setting output voltage to 5V or less, input voltage needs to be set to 6V or over to operate stably.
29
qSI-3000B
Series
sOutline
Drawing
φ
3.2
±0.2
0.5
(unit:mm)
10.0
±0.2
4.2
±0.2
±0.2
2.8
4.0
±0.2
7.9
±0.2
16.9
±0.3
(17.9)
Part Number
Lot Number
2.6
±0.1
(2.0)
Plastic Mold Package Type
Flammability: UL94V-0
Weight: Approx. 2.3g
SI-3157B
q
w
e
r
t
GND
V
C
V
O
V
OS
V
IN
SI-3025B
q
w
e
r
t
GND
V
C
V
O
V
REF
V
IN
0.95
±0.15
+0.2
0.85
–0.1
(4.6)
0.45
–0.1
P1.7
±0.7
×4=6.8
±0.7
+0.2
3.9
±0.7
8.2
(4.3)
±0.7
1 2 3 4 5
Forming No. 1101
sBlock
Diagram
SI-3157B
5
T
r1
3
MIC
5
(8.0)
5.0
±0.6
SI-3025B
T
r1
3
MIC
Reg.
4
Reg.
4
ON/OFF
Protection
Amp.
Drive
ON/OFF
Protection
Amp.
Drive
V
REF
2
Equivalent
to LS-TTL
2
Equivalent
to LS-TTL
1
1
30
V
REF
qSI-3000B
Series
sStandard
External Circuit
SI-3157B
D
1
*
2
3
C
0
: Output capacitor (47 to 100µF)
*1 C
1
: Oscillation prevention capacitor
C
2
+
C
0
DC Output
V
O
4
5
+
DC Input
V
IN
*
1
C
1
C
2
OPEN
SI-3157B
2
1
*2 D
1
SI-3025B
D
1
*
2
*3 R
1
R
2
5
+
DC Input
V
IN
3
SI-3025B
1
4
R
1
*
3
R
2
*
3
+
C
0
DC Output
V
O
*
1
C
1
OPEN 2
C
2
(C
1
: Approx. 47µF, C
2
: 0.33µF)
These capacitors are required if the input line is inductive
and in the case of long wiring. Tantalum capacitors are rec-
ommended for C
1
and C
0
, particularly at low temperatures.
: Protection diode
This diode is required for protection against reverse biasing
of the input and output. Sanken EU2Z is recommended.
: External resistor for setting output voltage
Relationship between output voltage V
O
and external resis-
tors R
1
and R
2
is as follows.
R
1
V
O
=V
REF
• 1+
(V
REF
=2.55V(typ.))
R
2
R
2
must be 2.55kΩ for stable operation.
sT
a
-P
D
Characteristics
15
Infinite heatsink
With Silicon Grease
Heatsink: Aluminum
20
Power Dissipation P
D
(W)
10
0
×
20
10
0
×
75
×
0
×
2m
5
.3
°
C
/W
(5.
75
)
2
°
×
2
C/
mm
W
)
(7.
6
°
C
/W
)
10
0
m
×
2
m
(2
m
Without heatsink
0
–30
0
25
50
75
100
Ambient Temperature T
a
(°C)
P
D
=I
O
•[V
IN
(mean)–V
O
]
31
qSI-3000B
Series
sTypical
Characteristics (When setting V
O
=15.7V for SI3025B)
(T
a
=25°C)
I
O
vs. V
DIF
Characteristics
0.5
Temperature Coefficient of Output Voltage(SI-3157B)
16.0
15.9
V
IN
=18V
l
O
=0A
Rise Characteristics(SI-3157B)
20
Dropout Voltage V
DIF
(V)
Output Voltage V
O
(V)
15.8
15.7
15.6
15.5
15.4
Output Voltage V
O
(V)
0.4
15
l
O
=0A
0.1A
0.2A
0.27A
0.3
10
0.2
5
0.1
0
0
0.05
0.1
0.15
0.2
0.25
0.3
15.3
–40 –20
0
20
40
60
80 100 120 140
0
0
5
10
15
20
25
30
Output Current I
O
(A)
Ambient Temperature T
C
(°C)
Input Voltage V
IN
(V)
Line Regulation
16.1
Load Regulation
16.1
Overcurrent Protection Characteristics(SI-3157B)
20
15.9
Output Voltage V
O
(V)
Output Voltage V
O
(V)
Output Voltage V
O
(V)
15.7
l
O
=0A
0.1A
0.2A
15.9
15
V
IN
=27V
V
IN
=16.5
15.7
V
IN
=27V
25V
22V
18V
16.5V
0.27A
15.5
V
15.5
10
15.3
15.3
18V
22V
5
25V
15.1
15.1
14.9
14
16
18
20
22
24
26
28
14.9
0
0.05
0.1
0.15
0.2
0.25
0.3
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Input Voltage V
IN
(V)
Output Current I
O
(A)
Output Current I
O
(A)
Output ON/OFF Control
20
V
IN
=18V
l
O
=0A
Thermal Protection Characteristics
20
Output Voltage V
O
(V)
Output Voltage V
O
(V)
15
15
V
IN
=18V
l
O
=10mA
10
10
5
5
0
0
1
2
3
4
0
0
20
40
60
80 100 120 140 160 180
Output ON/OFF Control V
C
(V)
Case Temperature T
C
(°C)
Note on Thermal Protection:
The thermal protection circuit is intended for pro-
tection against heat during instantaneous short-
circuiting. Its operation is not guaranteed for short-