46 ICs
■Features
•Surface-mount power package
•Output current: 0.4 to 0.5A
•High efficiency: 75 to 89%
•Requires only 4 discrete components
•Internally-adjusted phase correction and
output voltage
•Built-in reference oscillator (60kHz)
•Built-in overcurrent and thermal protection
circuits
■Applications
•Power supplies for telecommunication
equipment
•Onboard local power supplies
■Line up
■Electrical Characteristics (Ta=25°C)
Unit
V
%
kHZ
mV
mV
mV/°C
dB
A
Parameter
Output Voltage
Efficiency
Oscillation Frequency
Line Regulation
Load Regulation
Temperature Coefficient of Output Voltage
Ripple Rejection
Overcurrent Protection
Starting Current
Symbol
VO
Conditions
η
Conditions
f
Conditions
∆VOLINE
Conditions
∆VOLOAD
Conditions
∆VO/∆Ta
RREJ
Conditions
IS1
Conditions
■Absolute Maximum Ratings
Unit
V
W
°C
°C
°C/W
Ratings
35
0.75
+125
–40 to +125
20
Symbol
VIN
PD
Tj
Tstg
θ
j-c
Parameter
DC Input Voltage
Power Dissipation
Junction Temperature
Storage Temperature
Thermal Resistance(junction to case)
Part Number SAI01 SAI02 SAI03 SAI06
VO(V) 5.0 3.3 12.0 9.0
IO(A) 0.5 0.4
■Recommended Operating Conditions
Parameter
DC Input Voltage Range
Output Current Range
Operating Junction Temperature Range
Symbol
VIN
IO
Tjop
Unit
V
A
°C
Ratings
SAI01 SAI02 SAI03 SAI06
7 to 33 5.3 to 28 15 to 33 12 to 33
0 to 0.5 0 to 0.4
–30 to +125
Ratings
SAI01 SAI02 SAI03 SAI06
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 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
=21V, I
O
=0.3A
80 75 88 86
V
IN
=20V, I
O
=0.3A V
IN
=15V, I
O
=0.3A V
IN
=24V, I
O
=0.3A V
IN
=21V, I
O
=0.3A
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
=21V, I
O
=0.3A
80 100 60 80 100 130 90 110
VIN=10 to 30V, IO=0.3A VIN=8 to 28V, IO=0.3A VIN=18 to 30V, IO=0.3A VIN=15 to 30V, IO=0.3A
30 40 20 30 70 95 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
=21V, I
O
=0.1 to 0.4A
±0.5 ±0.5 ±1.5 ±1.0
45 45 45 45
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
V
IN
=10V V
IN
=8V V
IN
=18V V
IN
=15V
SAI Series
1-1-2 Switching Mode Regulator ICs
Surface-Mount, Separate Excitation Step-down Switching Mode Regulator ICs
47
ICs
SAI Series
■External Dimensions (PS4)
■Block Diagram ■Typical Connection Diagram
(unit : mm)
■Ta-PD Characteristics
PD=VO•IO 100 –1 –VF•IO 1–VO
ηχ
VIN
A
3VOS
4
.GND
2 SW
1VIN
6.8max.
4.0max.
4.7max.
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
V
IN
C
1
D
1
L1
3.3
V
5
V
: 200µH
9
V
12
V
15
V
: 300µH
100µF
C
2
330µF
V
IN
SFPB54
GND
GND
SAI
SW
OUT
V
OS
12
3
4
+ +
V
O
GND
(Sanken)
a. Part Number
b. Lot Number
A Case Temperature Measuring Point
Pin Assignment
qVIN
wSWOUT
eVOS
rGND
Plastic Mold Package Type
Flammability: UL94V-0
Product Mass: Approx. 0.22g
The efficiency depends on the input voltage and the output
current. Therefore, obtain the value from the efficiency graph
and substitute the percentage in the formula above.
VO:Output voltage
IO:Output current
ηχ
:Efficiency (%)
VF:Diode D1 forward voltage
SFPB54-0.3V
Thermal design for D1 must be considered separately.
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
board
(95×69×1.2)
• Natural air cooling
66
■Selecting External Components
1. Inductor L1
1) It must be suited for switching regulators.
Do not use inductors such as noise filters, because 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 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 should be a low-impedance type capacitor.
A low-impedance type capacitor is recommended for C2 to ensure reduced 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 fast recovery diode or any other diode, supplying a reverse voltage generated from the recover y or ON voltage of the diode may
damage the IC.
Application
Variable output voltage
Output voltage can be adjusted in the same way as SI-8000S in page 77.
■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 inter nal frame and termi-
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 67 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 P
D
(W)
Ambient Temperature T
a
(°C)
• Glass epoxy
substrate
(95
×
69
×
1.2)
• No airflow
●SAI Series
PD=VO•IO 100 –1 –VF•IO 1– VO
ηχ VIN
67
■Typical Characteristics
Output V oltage(SAI01) Efficiency Characteristics(SAI01) Load Regulation(SAI01)
Temperature Characteristics(SAI01)
Overcurrent Protection Characteristics(SAI01
)
Thermal Protection Characteristics(SAI01)
Output V oltage(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
VIN
=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 VO (V)
0 0.1 0.2 0.3
Output Current IO (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 IO (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 IO (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
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.
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 V
IN
(V)
15 20
T
a
=25°C
I
O
=0A
0.2A
0.4A
Output Voltage V
O
(V)
