1-1-2 Switching Mode Regulator ICs
SI-8000TFE Series
Full-Mold, Separate Excitation Step-down Switching Mode Regulator ICs
sFeatures
• Compact full-mold package (equivalent to
TO220)
• Output current: 1.5 A
• High efficiency: 81% typ. (at Vo = 5 V)
• Requires only 4 discrete components
• Built-in reference oscillator (300 kHz)
• Built-in dropping-type-overcurrent and thermal
protection circuits
• Output ON/OFF available (circuit current at
output OFF: 200
µ
A typ.)
• Soft start available by ON/OFF pin
Junction Temperature*
Storage Temperature
sLineup
Part Number
V
O
(V)
I
O
(A)
SI-8008TFE
Variable (0.8 to 24)
1.5
SI-8050TFE
5
sAbsolute
Maximum Ratings
Parameter
DC Input Voltage
Symbol
V
IN
P
D1-1
Power Dissipation
P
D1-2
P
D2-1
P
D2-2
T
j
T
stg
Ratings
43
17.8 (with infinite heatsink)
14.2 (with infinite heatsink)
2.15 (without heat sink, standalone operation)
1.72 (without heatsink, standalone operation)
–30 to +150
–40 to +150
7
58
°C
°C
°C/W
°C/W
W
Unit
V
Limited by thermal protection, T
jmax
=150°C
T
jmax
=125°C
Limited by thermal protection, T
jmax
=150°C
T
jmax
=125°C
Conditions
sApplications
• Onboard local power supplies
• AV equipment
• OA equipment
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient Air)
θ
j-c
θ
j-a
*: This product has built-in thermal protection circuits that may operate when the junction temperature rises above 130°C.
The recommended design for the junction temperature during operation is below 125°C.
sRecommended
Operating Conditions
Ratings
Parameter
Input Voltage Range
Output Voltage Range
Output Current Range
Operating Junction Temperature Range
Operating Temperature Range
Symbol
V
IN
V
O
I
O
T
jop
T
op
SI-8008TFE
Vo+3
*1
to 40
0.8 to 24
0 to 1.5
–20 to +125
–20 to +125
SI-8050TFE
8 to 40
5.0
Unit
(T
a
=25°C)
V
V
A
°C
°C
*1: The minimum value of an input voltage range is the higher of 4.5 V or V
O
+ 3 V.
sElectrical
Characteristics
Ratings
Parameter
Symbol
Ratings
(T
a
=25°C)
min.
Output Voltage
(Reference Voltage)
Temperature Coefficient of Output Voltage
(Temperature Coefficient of Reference Voltage)
Efficiency
Oscillation Frequency
Line Regulation
Load Regulation
Overcurrent Protection
Starting Current
Low Level Voltage
ON/OFF Pin*
Low Voltage
SI-8008TFE
typ.
0.800
V
IN
=15V, I
o
=0.1A
max.
Vo
(V
ADJ
)
Conditions
min.
4.90
SI-8050TFE
typ.
5.00
Unit
max.
5.10
V
0.784
0.816
V
IN
=15V, I
o
=0.1A
±0.5
∆Vo/∆T
(∆V
REF
/∆T)
Conditions
η
Conditions
±0.1
V
IN
=15V, I
o
=0.1A, T
c
=0 to 100°C
81
V
IN
=15V, I
o
=0.5A
300
V
IN
=15V, I
o
=0.5A
60
V
IN
=10 to 30V, I
o
=0.5A
10
V
IN
=15V, I
o
=0.2 to 1.5A
1.6
mV/°C
V
IN
=15V, I
o
=0.1A, T
c
=0 to 100°C
81
V
IN
=15V, I
o
=0.5A
300
V
IN
=15V, I
o
=0.5A
60
V
IN
=10 to 30V, I
o
=0.5A
10
V
IN
=15V, I
o
=0.2 to 1.5A
1.6
%
kHz
fo
Conditions
∆V
OLINE
Conditions
80
40
80
40
mV
mV
A
∆V
OLOAD
Conditions
I
S
Conditions
V
IN
=15V
10
V
SSL
=0V
6
V
IN
=15V, I
o
=0A
200
V
IN
=15V, V
SS
=0V
400
0.5
40
V
IN
=15V
10
V
SSL
=0V
6
V
IN
=15V, I
o
=0A
200
V
IN
=15V, V
SS
=0V
400
0.5
40
V
SSL
Outflow Current at
I
SSL
Conditions
V
µA
mA
µA
I
q
Quiescent Circuit Current
Conditions
I
q(OFF)
Conditions
*: Pin 5 is the SS pin. Soft start at power on can be performed with a capacitor connected to this
pin. The output can also be turned ON/OFF with this pin. The output is stopped by setting the
voltage of this pin to VSSL or lower. SS-pin voltage can be changed with an open-collector
drive circuit of a transistor. When using both the soft-start and ON/OFF functions together, the
discharge current from C3 flows into the ON/OFF control transistor. Therefore, limit the cur-
rent securely to protect the transistor if C3 capacitance is large. The SS pin is pulled up to the
power supply in the IC, so applying the external voltage is prohibited. If the pin is not used,
leave it open.
SI-8000TFE
SI-8000TFE
SI-8000TFE
5 SS
5 SS
C3
5 SS
C3
V
O.
ON/OFF
Soft start
Soft start
+V
O.
ON/OFF
64
ICs