SPI-8000A_11 SANKEN [Sanken electric], SPI-8000A_11 Datasheet - Page 3

• Manufacturer Part Number: SPI-8000A_11
• Description: Surface Mount, Separate Excitation Step-down Switching Mode
• Manufacturer: SANKEN [Sanken electric]

1-1-3 DC/DC Converter ICs
■Typical Connection Diagram
■T
24
a
Diode D
• Be sure to use a Schottky-barrier diode for D
Choke coil L
• If the winding resistance of the choke coil is too high, the efficiency may drop below the rated value.
• As the overcurrent protection starting current is about 4.5A, take care concerning heat radiation from the choke coil caused by magnetic saturation due to
Capacitors C
• As large ripple currents flow through C
Resistors R
• R
-P
generated by the recovery voltage or ON voltage.
overload or short-circuited load.
when the impedance of C
equivalent series resistance (ESR) such as an OS capacitor or a tantalum capacitor, which may cause an abnormal oscillation.
To create the optimum operating conditions, place the components as close as possible to each other.
2
D
and R
Characteristics
ICs
1
3
2
1
are the resistors to set the output voltage. Set their values so that I
, R
1
3.00
2.50
2.00
1.50
1.00
0.50
, C
3
0
–30
2
GND
θ
θ
θ
j-a:41.7°C/W(30.8cm
j-a:47.6°C/W(8.64cm
j-a:62.5°C/W(0.84cm
V
IN
R2=
C1
Ambient Temperature T
0
(V
2
+
is high, the switching waveform may become abnormal at low temperatures. For C
OUT
2
2
2
)
)
)
25
I
REF
–V
REF
C7
50
)
=
1
and C
(V
2×10
OUT
75
C4
11
4
–1)
a
–3
2
1
, use high-frequency and low-impedance capacitors aiming for switching-mode-power-supply use. Especially
(°C)
. If other diodes like fast recovery diodes are used, ICs may be destroyed because of the reverse voltage
V
CE/SS
5
Reg
100
IN
(Ω), R3 =
C5
14
Comp
SPI-8010A
125
C6
V
I
AGND
1
REF
REF
SPI-8010A
=
2×10
DGND
1
SW
12
3
–3
B.S
V
OUT
REF
= . .
500(Ω)
REF
R1
15
7
P
becomes approx. 2mA. Obtain R
D
=V
C3
D1
Note 1: The efficiency depends on the input voltage and the output cur-
Note 2: Thermal design for D
V
V
I
ηχ : Efficiency (%)
V
O
O
IN
F
O
R2
R3
: Output voltage
: Input voltage
: Output current
: Diode D
• I
L1
SPB-G56S···0.4V(I
O
rent. Therefore, obtain the value from the efficiency graph and
substitute the percentage in the formula above.
I
REF
100
ηχ
1
forward voltage
+
–1 –V
C2
2
O
F
, do not use a capacitor with an extremely low
=2A)
C8
• I
V
GND
O
2
0
1
and R
1–
must be considered separately.
V
V
3
values by the following formula:
IN
O
C1: 220 µ F/63V
C2: 470 µ F/25V
C3: 0.1 µ F
C4: 1000pF
C5: 0.1 µ F
C6: 0.047 µ F
C7: 0.1 µ F
C8: 0.1 µ F
R1: 47Ω
L1: 47 µ H
D1: SPB-G56S
(Sanken)