82
Unit
V
A
°C
■Features
•Integrated switching IC and coil construction
•Requires 2 external components only
•Low switching noise
•Heatsink not required
•Built-in overcurrent and thermal protection circuits
•Built-in soft start circuit (Output ON/OFF control)...SI-8500L Series
■Applications
•Telephone power supplies
•Onboard local power supplies
■Lineup
Separate Excitation Switching Type with Coil
Symbol
VIN
PD
Tj
Tstg
SI-8400L/8500L Series
■Recommended Operating Conditions
■Absolute Maximum Ratings
Unit
V
A
°C
Unit
V
W
°C
°C
Symbol
VIN
IO
Top
Symbol
VIN
IO
Top
Ratings
SI-8400L SI-8500L
35
1.25 3
+100
–25 to +85
Part Number SI-8401L SI-8402L SI-8403L SI-8405L SI-8501L SI-8502L SI-8503L SI-8504L SI-8505L
VO(V) 5.0 12.0 3.3 15.0 5.0 12.0 3.3 9.0 15.0
IO(A) 0.5 0.4 0.5 0.4 1.0
Parameter
DC Input Voltage Range
Output Current Range
Operating Temperature Range
Parameter
DC Input Voltage Range
Output Current Range
Operating Temper ature Range
Parameter
DC Input Voltage
Power Dissipation
Junction Temper ature
Storage Temperature
Ratings
SI-8401L SI-8402L SI-8403L SI-8405L
7 to 33 15 to 33 5.3 to 33 18 to 33
0 to 0.5 0 to 0.4 0 to 0.5 0 to 0.4
–20 to +85
Ratings
SI-8501L SI-8502L SI-8503L SI-8504L SI-8505L
7 to 33 15 to 33 5.3 to 33 12 to 33 18 to 33
0 to 1.0
–20 to +85
●SI-8400L/8500L Series
83
(Ta=25°C)
Unit
V
%
kHZ
mV
mV
mV/°C
mVp-p
A
■Electrical Characteristics (Ta=25°C)
Unit
V
%
kHZ
mV
mV
mV/°C
mVp-p
A
Symbol
VO
Conditions
η
Conditions
f
Conditions
∆VOLINE
Conditions
∆VOLOAD
Conditions
∆VO/∆Ta
∆Vr
Conditions
IS1
Conditions
Parameter
Output V oltage
Efficiency
Switching Frequency
Line Regulation
Load Regulation
Temperature Coefficient of Output Voltage
Switching Ripple
Voltage (C2=470µF)
Overcurrent Protection
Starting Current
Parameter
Output V oltage
Efficiency
Switching Frequency
Line Regulation
Load Regulation
Temperature Coefficient of Output Voltage
Switching Ripple
Voltage (C2=470µF)
Overcurrent Protection
Starting Current
Symbol
VO
Conditions
η
Conditions
f
Conditions
∆VOLINE
Conditions
∆VOLOAD
Conditions
∆VO/∆Ta
∆Vr
Conditions
IS1
Conditions
Ratings
SI-8401L SI-8402L SI-8403L SI-8405L
min. typ. max. min. typ. max. min. typ. max. min. typ. max.
4.80 5.00 5.20 11.40 12.00 12.60 3.17 3.30 3.43 14.25 15.00 15.75
V
IN
=20V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=27V, I
O
=0.3A
80 88 75 89
V
IN
=20V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=27V, I
O
=0.3A
60 60 60 60
V
IN
=20V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=27V, I
O
=0.3A
80 100 100 130 60 80 100 130
V
IN
=10 to 30V, I
O
=0.3A V
IN
=18 to 30V, I
O
=0.3A V
IN
=8 to 30V, I
O
=0.3A V
IN
=21 to 30V, I
O
=0.3A
30 40 70 95 20 30 90 120
V
IN
=20V, I
O
=0.1 to 0.4A V
IN
=24V, I
O
=0.1 to 0.4A V
IN
=15V, I
O
=0.1 to 0.4A V
IN
=27V, I
O
=0.1 to 0.4A
±0.5 ±1.5 ±0.5 ±1.5
20 40 35 70 15 30 40 80
V
IN
=20V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=27V, I
O
=0.3A
0.55 0.45 0.55 0.45
V
IN
=10V V
IN
=18V V
IN
=8V V
IN
=21V
Ratings
SI-8501L SI-8502L SI-8503L SI-8504L SI-8505L
min. typ. max. min. typ. max. min. typ. max. min. typ. max. min. typ. max.
4.80 5.00 5.20 11.40 12.00 12.60 3.17 3.30 3.43 8.55 9.00 9.45 14.25 15.00 15.75
V
IN
=20V, I
O
=0.5A V
IN
=24V, I
O
=0.5A V
IN
=15V, I
O
=0.5A V
IN
=21V, I
O
=0.5A V
IN
=25V, I
O
=0.5A
83 89 79 87 90
V
IN
=20V, I
O
=0.5A V
IN
=24V, I
O
=0.5A V
IN
=15V, I
O
=0.5A V
IN
=21V, I
O
=0.5A V
IN
=25V, I
O
=0.5A
60 60 60 60 60
V
IN
=20V, I
O
=0.5A V
IN
=24V, I
O
=0.5A V
IN
=15V, I
O
=0.5A V
IN
=21V, I
O
=0.5A V
IN
=25V, I
O
=0.5A
70 130 70 130 50 80 70 130 70 130
V
IN
=10 to 30V, I
O
=0.5A V
IN
=18 to 30V, I
O
=0.5A V
IN
=8 to 30V, I
O
=0.5A V
IN
=15 to 30V, I
O
=0.5A V
IN
=21 to 30V, I
O
=0.5A
30 55 30 55 20 45 30 55 30 55
V
IN
=20V, I
O
=0.2 to 0.8A V
IN
=24V, I
O
=0.2 to 0.8A V
IN
=15V, I
O
=0.2 to 0.8A V
IN
=21V, I
O
=0.2 to 0.8A
V
IN
=25V, I
O
=0.2 to 0.8A
±0.5 ±1.5 ±0.5 ±1.0 ±1.5
45 30 15 25 30
V
IN
=20V, I
O
=0.5A V
IN
=24V, I
O
=0.5A V
IN
=15V, I
O
=0.5A V
IN
=21V, I
O
=0.5A V
IN
=25V, I
O
=0.5A
1.1 1.1 1.1 1.1 1.1
V
IN
=18V V
IN
=24V V
IN
=12V V
IN
=21V V
IN
=25V
●SI-8400L/8500L Series
84
■External Dimensions
a. Part Number
b. Lot Number
Open Air Type
Weight: Approx. 5.1g
SI-8400L SI-8500L
a. Part Number
b. Lot Number
Open Air Type
Weight: Approx. 14.5g
SI-8400L SI-8500L
■Block Diagram
■Standard External Circuit
;;
;;;
;;;;
;;;;
;;;
;
q
e
w
rV
IN
Vo
0.8max.
L
IN
GND
(10.16) (7.62) (2.19)(2.17)
14.5
±0.5
12
±0.5
13.2
±0.6
10
±0.2
4.7
±0.6
φ
ab
Terminal 1 marking
y
qwe
r
SK
V
IN
V
OUT
SS GND
L
IN
18
3.7
26
±0.1
26
±0.1
0.6 418
2
φ
ab
Terminal 1 marking
Reg. OCP
OSC Reset
Amp.
TSD
V
REF
Comp.
Latch
&
Drive
2
VIN VO
LIN
L1
Di1
MIC1
GND
41
3
V
O
V
IN
GND GND
C
1
C
2
220µF470µF
++
14
3
N.C
2
V
OUT
L
IN
GND
SI-8400L
V
IN
VOVIN
GND GND
C1C2
C3
470µF470µF
++
16
34
N.C
2
VOUT
LINGNDS.S
SI-8500L
VIN
Pin compatible with SI-8200L C3 is necessary only for using soft start function.
Pin compatible with SI-8300L
32
Di1
MIC1
GND
S.S.
61
4
L1
Reg. OCP
OSC Reset
Amp.
TSD
V
REF
Comp.
Latch
&
Drive
VIN VO
LIN
●SI-8400L/8500L Series
(unit:mm)
85
■Ta-PD Characteristics
■SI-8500L application circuit
Terminal no.2 is for soft start. Connecting a capacitor to the terminal
enables the soft start function. See page 77 for the f ormulas to calcu-
late delay time and rise time. Output can be turned on and off by
using the soft start terminal. To stop output, set the soft start terminal
voltage to VSSL (0.2V typ.) or less. To switch the potential of the soft
start terminal, drive the open collector of the transistor. Since the
discharge current from C3 flows to the ON/OFF control tr ansistor, limit
the current for protection. The SS terminal is pulled up to the power
supply in the IC and no external voltage can be applied.
■Caution
1. Allocation of Components
For the best oper ating environment, the ground should be a single g round line at the GND terminal (terminal 2 on the SI-8400L, terminal 3 on
the SI-8500L), and the wiring from C1 and C2 to ground should be as short as possible.
2. Capacitors C1 and C2
1) They must satisfy the breakdown voltage and allowable ripple current.
Exceeding the ratings of these capacitors or using them without derating shortens their service lives and may also cause abnormal
oscillation of the IC.
2) C2 must be a low-impedance type capacitor to ensure minimum ripple voltage and stable switching operation.
3) C3 (SI-8500L only) is a capacitor for soft start. When not using soft start, leave terminal 2 open. It is pulled up inside the IC.
3. Terminals LIN and NC in the connection diagram must be left unconnected to other circuits.
4. The IC's metalic heatsink is electrically floating. Do not connect it to GND or any other circuit.
5. Since the SI-8400L and 8500L series have an open-package construction, they can only be operated in specific environments. Verify the
operating environment and use the conditions indicated in the reliability data.
1.5
1.0
0.5
002550
Ambient Temperature Ta (°C)
Power Dissipation PD (W)
75 100
SI-8400L
3.0
2.0
1.0
00 25 50 75 100
SI-8500L
Ambient Temperature Ta (°C)
Power Dissipation PD (W)
SI-8500L SI-8500L
S.S.2 S.S.2 S.S.
C
3
C
3
2
V
O.
ON/OFF Soft start Soft start +V
O
ON/OFF
SI-8500L
●SI-8400L/8500L Series
VO:Output voltage
IO:Output current
ηχ :Efficiency (%)
The efficiency depends on the input
voltage and the output current. Thus,
obtain the value from the efficiency
graphs on p .86, 87 and substitute the
percentage in the formula above.
PD=VO•IO 100 –1
ηχ
86
■Typical Characteristics (SI-8400L Series)
Output V oltage(SI-8401L) Efficiency Characteristics(SI-8401L) Load Regulation(SI-8401L)
Temperature Characteristics(SI-8401L)
Overcurrent Protection Characteristics(SI-8401L) Thermal Protection Characteristics(SI-8401L)
Output V oltage(SI-8402L) Efficiency Characteristics(SI-8402L) Load Regulation(SI-8402L)
0
6
5
4
3
2
1
0246
Input Voltage V
IN
(V)
Output Voltage V
O
(V)
810
T
a
=25°C
I
O
=0A
0.5A
0.3A
0.1A
Output Current I
O
(A)
Efficiency η (%)
0
100
90
80
70
60
50
00.1 0.2 0.3 0.4 0.5
T
a
=25°C
V
IN
7V
10V
20V
25V
33V
20V
25V
33V
10V
7V
Output Voltage VO (V)
Output Current IO (A)
0
5.3
5.2
5.1
5.0
4.9
4.8
00.1 0.2 0.3 0.4 0.5
T
a
=25°C
V
IN
=33V 20V
10V
7V
V
IN
=20V, I
O
=0.3A
Output Voltage VO (V)
–40
00
100
90
80
70
60
50
40
5.3
5.2
5.1
5.0
4.9
4.8
4.7
–20 0 20
Ambient Temperature Ta (°C)
Efficiency η (%) Frequency f (kHz)
40 60 80 100
VO
f
η
Output Voltage V
O
(V)
Output Current I
O
(A)
0
6
5
4
3
2
1
00.5 1.0 1.5 2.0
T
a
=25°C
20V
33V
V
IN
=7V
Output Voltage V
O
(V)
0
6
5
4
3
2
1
050 100
Case Temperature T
C
(°C)
150 200
V
IN
=20V, I
O
=20mA
0
14
12
10
6
8
2
0
4
510
Input Voltage V
IN
(V)
Output Voltage V
O
(V)
15 20
T
a
=25°C
0.4A
0.2A
I
O
=0A
0
100
90
80
70
60
50
00.1 0.2 0.3 0.4
V
IN
=15V
24V
33V
Output Current I
O
(A)
Efficiency η (%)
T
a
=25°C
Output Voltage V
O
(V)
0
12.3
12.2
12.1
12.0
11.9
11.8
00.1 0.2 0.3 0.4
V
IN
=33V
24V
20V
15V
Output Current I
O
(A)
T
a
=25°C
●SI-8400L/8500L Series
Note on Thermal Protection:
The thermal protection cir cuit is intended f or
protection a gainst heat during instantaneous
short-circuiting. Its operation is not guaran-
teed for continuous heating condition such
as short-circuiting over extended periods of
time.
87
■Typical Characteristics (SI-8500L Series)
Output V oltage(SI-8501L) Efficiency Characteristics(SI-8501L) Load Regulation(SI-8501L)
Temperature Characteristics(SI-8401L)
Overcurrent Protection Characteristics(SI-8401L) Thermal Protection Characteristics(SI-8401L)
Output V oltage(SI-8502L) Efficiency Characteristics(SI-8502L) Load Regulation(SI-8502L)
0
7
6
5
4
3
2
1
05101520
Ta=25°C
I
O
=0A
1A
0.5A
Input Voltage VIN (V)
Output Voltage VO (V)
0
100
90
80
70
60
50
40
00.25 0.5 0.75 1
T
a
=25°C
V
IN
=7V
20V
33V
Output Current I
O
(A)
Efficiency η (%)
0
5.15
5.10
5.05
5.00
4.95
4.90
4.85
00.25 0.5 0.75 1
Ta=25°C
20V
15V
V
IN
=33V
7V
Output Voltage V
O
(V)
Output Current I
O
(A)
–40 0
5.15
5.10
5.05
5.00
4.95
4.90
4.85
0 40 80 120
V
O
η
f
V
IN
=20V, I
O
=0.5A
Output Voltage VO (V)
0
100
90
80
70
60
50
40
Ambient Temperature Ta (°C)
Efficiency η (%) Frequency f (kHz)
0
7
6
5
4
3
2
1
01234
V
IN
=7V
20V
T
a
=25°C
33V
Output Voltage VO (V)
Output Current IO (A)
0
7
6
5
4
3
2
1
040 80 120 160
Output Voltage V
O
(V)
Ambient Temperature T
a
(°C)
V
IN
=20V, I
O
=0A
0
14
12
10
6
8
2
0
4
5101520
Input Voltage V
IN
(V)
Output Voltage V
O
(V)
T
a
=25°C
I
O
=0A
1A
0.5A
0
100
90
80
60
70
40
0
50
0.25 0.5 0.75 1.0
V
IN
=15V
24V
33V
Output Current I
O
(A)
Efficiency η (%)
T
a
=25°C
0
12.3
12.2
12.1
11.9
12.0
11.7
0
11.8
0.25 0.5 0.75 1
Output Voltage VO (V)
VIN=33V 24V
18V
15V
Output Current IO (A)
Ta=25°C
●SI-8400L/8500L Series
Note on Thermal Protection:
The thermal protection circuit is intended f or
protection against heat during instantaneous
short-circuiting. Its operation is not guaran-
teed for continuous heating condition such
as short-circuiting over extended periods of
time.