72
Parameter
DC Input Voltage
Po wer Dissipation
Junction Temperature
Storage Temperature
SW Terminal Applied Reverse Voltage
Thermal Resistance(junction to case)
Parameter
DC Input Voltage Range
Output Current Range
Operating Junction Temperature Range
Symbol
VIN
PD
Tj
Tstg
VSW
Rth(j-c)
■Features
• Surface-mount package
• Output current: 0.4 to 0.5A
• High efficiency: 75 to 89%
• Requires only 4 external components
• Phase correction and output voltage adjustment performed internally
• Built-in reference oscillator (60kHz)
• Built-in overcurrent and thermal protection circuits
■Applications
• Power supplies for telecommunication equipment
• Onboard local power supplies
■Lineup
SAI Series
Surface-Mount, Separate Excitation Switching Type
●SAI Series
Unit
V
A
°C
Symbol
VIN
IO
Tjop
■Absolute Maximum Ratings
■Recommended Operating Conditions
Part Number SAI01 SAI02 SAI03 SAI04 SAI06
VO(V) 5.0 3.3 12.0 15.0 9.0
IO(A) 0.5 0.4
Ratings
35
0.75
+125
–40 to +125
–1
20
Unit
V
W
°C
°C
V
°C/W
Ratings
SAI01 SAI02 SAI03 SAI04 SAI06
7 to 33 5.3 to 28 15 to 33 18 to 33 12 to 33
0 to 0.5 0 to 0.4
–30 to +125
73
Parameter
Output V oltage
Efficiency
Switching Frequency
Line Regulation
Load Regulation
Temperature Coefficient of Output Voltage
Ripple Rejection
Overcurrent Protection
Starting Current
■Electrical Characteristics (Ta=25°C)
●SAI Series
■Outline Drawing
Plastic Mold Package Type
Flammability: UL94V-0
Weight: Approx. 0.22g
a. Part Number
b. Lot Number
A Case temperature measuring point
qVIN
wSWOUT
eVOS
rGND
■Block Diagram
A
3V
OS
4
.GND
2 SW
1V
IN
6.8
max.
4.0
max.
4.7
max.
2.54
±0.25
4.32
±0.2
8.0
±0.5
3.6
±0.2
1.4
±0.2
3.0
±0.2
9.8
±0.3
0~0.15
6.3
±0.2
1.0
±0.3
0.89
±0.15
0.25 0.75
+0.15
–0.05
0.3
+0.15
–0.05
ab
SWOUT
VOS
VIN
4
GND
3
21
OSC
Reg. OCP
Comp.
Reset Drive TSD
Amp.
VREF
Symbol
VO
Conditions
η
Conditions
f
Conditions
∆VOLINE
Conditions
∆VOLOAD
Conditions
∆VO/∆Ta
RREJ
Conditions
IS1
Conditions
■Standard External Circuit
V
IN
C
1
D
1
L1
3.3
V
5
V
: 200µH
9
V
12
V
15
V
: 300µH
100µFC
2
330µF
V
IN
SFPB54
GND
GND
SAI
SW
OUT
V
OS
12
3
4
+ +
V
O
GND
(Sanken)
Unit
V
%
kHZ
mV
mV
mV/°C
dB
A
Ratings
SAI01 SAI02 SAI03 SAI04 SAI06
min. typ. max. min. typ. max. min. typ. max. min. typ. max. min. typ. max.
4.80 5.00 5.20 3.17 3.30 3.43 11.40 12.00 12.60 14.25 15.00 15.75 8.55 9.00 9.45
V
IN
=20V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=27V, I
O
=0.3A V
IN
=21V, I
O
=0.3A
80 75 88 89 86
V
IN
=20V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=27V, I
O
=0.3A V
IN
=21V, I
O
=0.3A
60 60 60 60 60
V
IN
=20V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=27V, I
O
=0.3A V
IN
=21V, I
O
=0.3A
80 100 60 80 100 130 100 130 90 110
VIN=10 to 30V, IO=0.3A VIN=8 to 28V, IO=0.3A VIN=18 to 30V, IO=0.3A VIN=21 to 30V, IO=0.3A VIN=15 to 30V, IO=0.3A
30 40 20 30 70 95 90 120 50 80
V
IN
=20V, I
O
=0.1 to 0.4A V
IN
=15V, I
O
=0.1 to 0.4A V
IN
=24V, I
O
=0.1 to 0.4A V
IN
=27V, I
O
=0.1 to 0.4A V
IN
=21V, I
O
=0.1 to 0.4A
±0.5 ±0.5 ±1.5 ±1.5 ±1.0
45 45 45 45 45
f=100 to 120H
Z
f=100 to 120H
Z
f=100 to 120H
Z
f=100 to 120H
Z
f=100 to 120H
Z
0.55 0.55 0.45 0.45 0.45
V
IN
=10V V
IN
=8V V
IN
=18V V
IN
=21V V
IN
=15V
(unit: mm)
74
■Selecting External Components
1. Inductor L1
1) It must be suited for switching regulators.
Do not use inductors as noise filters as they generate excessive heat.
2) It must have the appropriate inductance value.
If the inductance is too small (150µH or lower), abnormal oscillation may occur causing operation problems in the overcurrent protection
circuit within the rated current range.
3) The rated current must be satisfied.
If the rated current is exceeded, magnetic saturation leads to overcurrent.
2. Capacitors C1 and C2
1) They must satisfy the withstand 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.
A low-impedance type capacitor is recommended for C2 to ensure minimum ripple voltage and stable switching operation.
3. Diode D1
The Sanken SFPB54 diode is recommended for D1. If you intended to use an equivalent diode, be sure to use a Schottky Barrier diode and
make sure that the reverse voltage applied to terminal 2 of the IC does not exceed the value (–1V) given in the absolute maximum ratings. If
you use a f ast recov ery diode or any other diode, application of a rev erse v oltage generated from the reco very or ON voltage of the diode ma y
damage the IC.
Application
Variable output voltage
Output voltage can be adjusted in the same way as SI-8000S in page 85.
■Example of Printed Circuit Board
a) For optimum operation, there must be only
one GND line originating from terminal 4
and each component must be connected
with the shortest possible wiring.
b) To prevent heating of the IC, it is best to
make the GND pattern as large as pos-
sible since the internal frame and ter mi-
nal 4 (GND) are connected to each other .
■Ta-PD Characteristics
The efficiency depends on the input v oltage and the out-
put current. Thus, obtain the value from the efficiency
graph on page 75 and substitute the percentage in the
formula above.
VO:Output voltage
IO:Output current
ηx:Efficiency (%)
VF:Diode forward voltage
SFPB54-0.3V
Thermal design for D1 must be considered separately.
+
+
V
IN
DI
1
C
1
L
1
C
2
GND
SW
V
O
12
34
SAI
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
–30 0 25 50 75 100 125
Power Dissipation PD (W)
Ambient Temperature Ta (°C)
• Glass epoxy
substrate
(95×69×1.2)
• Natural cooling
●SAI Series
PD=VO•IO 100 –1 –VF•IO 1– VO
ηχ VIN
75
■Typical Characteristics
Rise Characteristics(SAI01) Efficiency Characteristics(SAI01) Load Regulation(SAI01)
Temperature Characteristics(SAI01)
Overcurrent Protection Characteristics(SAI01
)
Thermal Protection Characteristics(SAI01)
Rise Characteristics(SAI03) Efficiency Characteristics(SAI03) Load Regulation(SAI03)
100
90
80
70
60
50
40
0
Efficiency η (%)
0 0.1 0.2 0.3
Output Current IO (A) 0.4 0.5
Ta=25°C
V
IN
=7V
20V
33V
10V
25V
5.3
5.2
5.1
5.0
4.9
4.8
4.7
0
V
IN
=33V 20V
10V
7V
Output Voltage V
O
(V)
0 0.1 0.2 0.3
Output Current I
O
(A)
0.4 0.5
T
a
=25°C
100
90
80
70
60
50
40
0
Efficiency η
(%) Frequency f (kHz)
Output Voltage V
O
(V)
–50 0 50
Ambient Temperature T
a
(°C)
100 150
V
IN
=20V, I
O
=0.3A
V
O
f
5.3
5.2
5.1
5.0
4.9
4.8
4.7
0
η
0
100
90
80
70
60
50
40
00.1 0.2
Output Current I
O
(A)
0.3 0.4
T
a
=25°C
V
IN
=15V
24V
33V
Efficiency
η (%)
0
12.3
12.2
12.1
12.0
11.9
11.8
00.1 0.2
Output Current I
O
(A)
0.3 0.4
Output Voltage V
O
(V)
T
a
=25°C
V
IN
=33V
24V
20V
15V
Output Voltage V
O
(V)
6
5
4
3
2
1
00 0.5 1.0
Output Current I
O
(A)
1.5 2.0
T
a
=25°C
V
IN
=7V
20V
33V
●SAI Series
Note on Thermal Protection:
The thermal protection cir cuit is intended for pr o-
tection against heat during instantaneous short-
circuiting. Its operation is not guaranteed for short-
circuiting over extended periods of time.
6
5
4
3
2
1
00246
Input Voltage V
IN
(V)
0.1A
Output Voltage V
O
(V)
810
T
a
=25°C
I
O
=0A
0.5A
0
6
5
4
3
2
1
050 100
Case Temperature T
C
(°C)
150 200
V
IN
=20V, I
O
=20mA
Output Voltage V
O
(V)
0
14
12
10
8
6
4
2
0510
Input Voltage VIN (V)
15 20
Ta=25°C
I
O
=0A
0.2A
0.4A
Output Voltage VO (V)