SPI-8001TW_11 SANKEN [Sanken electric], SPI-8001TW_11 Datasheet - Page 4

• Manufacturer Part Number: SPI-8001TW_11
• Description: 2-Output, Step-down Switching Mode
• Manufacturer: SANKEN [Sanken electric]

■Typical Connection Diagram
■T
a
Diodes Di1, Di2
• Be sure to use Schottky-barrier diodes for Di1 and Di2.
Choke coils L1, L2
• 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 2.0A, take care concerning heat radiation from the choke coil caused by magnetic saturation due to
• Use a closed-magnetic-path coil to prevent interference between the channels SW
Capacitors C1, C2, C3
• As large ripple currents flow through C1, C2 and C3, use high-frequency and low-impedance capacitors suitable for switching mode power supplies.
Resistors R1, R2, R3, R4
• R1, R2, R3 and R4 are resistors for setting output voltages. Set the resistors so that I
Note 1: The efficiency depends on the input voltage and the output current. Therefore, obtain the value from the efficiency graph and substitute the percent-
Note 2: Thermal design for D
-P
GND
If other diodes like fast recovery diodes are used, IC may be destroyed because of the reverse voltage generated by the recovery voltage or ON voltage.
overload or short-circuited load.
Especially when the impedance of C2 and C3 are high, the switching waveforms may become abnormal at low temperatures. For C2 and C3, do not use
capacitors with extremely low equivalent series resistance (ESR) such as OS capacitors or tantalum capacitors, which may cause abnormal oscillation.
shown below.
To create the optimum operating conditions, place the components as close as possible to each other.
V
D
IN
C1
C2, C3
C4, C5
C6, C7, C8 : 0.1 µ F
Characteristics
R1=
C6
age in the formula above.
(V
+
C1
O1
I
REF1
–V
C4
R5
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
–25
: 220 µ F/50V
: 470 µ F/25V
: 1 µ F
REF1
R6
C5
35.8°C/W (30.8 cm
38.2°C/W (15.6 cm
42.6°C/W (8.64 cm
52.3°C/W (3.34 cm
69.2°C/W (0.84 cm
θ j-a
)
(Copper Laminate Area)
=
0
Ambient Temperature T
15
11
12
2
6
5
(V
1 × 10
V
SS1
DGND1
V
SS2
DGND2
1
2
2
2
2
2
25
IN1
IN2
)
)
)
)
)
O1
must be considered separately.
3
V
–V)
CC
SPI-8000TW
–3
AGND
Ch1
Ch2
50
1, 9
14
( Ω ), R2=
C/E
R5, R6
L1, L2
Di1, Di2
(Sanken)
SWout1
SWout2
V
V
75
REF1
REF2
13
10
100
4
7
a
V
I
REF1
(°C)
REF1
: 1kΩ
: 47 µ H
: SJPB-H6
125 135 150
Di1
Di2
I
I
REF1
REF2
L1
L2
=
1 × 10
1
R1
R2
R3
R4
–3
+
+
C2
C3
= . .
1(K Ω )
C7
C8
V
V
V
GND
C/E
01
02
P
GND
D
V
= V
out
IN
V
V
I
ηχ : Efficiency (%)
V
O
C1
C2, C3
C4
C5, C6
C7, C8
1 and SW
O
IN
F
REF
O
C4
·I
: Output Voltage
: Input Voltage
: Output Current
: D
O
SJPB-H6···0.45V (I
is approx. 1 mA. For example, R1 and R2 can be calculated as
SPI-8001TW/SPI-8002TW/SPI-8003TW
1
Forward Voltage
+
100
C1
ηχ
out
C5
R5
2.
–1 – V
: 220 µ F/50V
: 470 µ F/25V
: 1 µ F/50V
: 1 µ F/10V
: 0.1 µ F/50V
R6
C6
F
16
12
13
2
6
5
·I
O
1, 9
O
=1A)
V
SS1
DGND1
V
SS2
DGND2
AGND
1–
IN1
IN2
3
V
SPI-8003TW
CC
V
V
8
C9
O
IN
C
Ch1
Ch2
ORC
15
C9
L1, L2
R2, R4
R5, R6
Di1, Di2
C/E
SWout1
SWout2
10
R7
R
V
V
CSC
REF1
REF2
14
11
4
7
: 100pF/10V
: 47 µ H
: 1kΩ
: 1kΩ
: SJPB-H6 (Sanken)
Di1
Di2
I
I
REF1
REF2
L1
L2
R1
R2
R3
R4
+
+
C2
C3
C7
C8
ICs
V
V
V
GND
C/F
C1
C2
61