SANKEN SPI

1-1-3 DC/DC Converter ICs
SPI-8000A Series
Surface Mount, Separate Excitation Step-down Switching Mode
■Features
■Absolute Maximum Ratings
• Surface-mount 16 pin package
Parameter
(Ta=25°C)
Symbol
Ratings
Unit
• Output current: 3.0A
DC Input Voltage
VIN
53
V
• High efficiency: 91% (at VIN = 10V, lO = 1A, VO
= 5V)
Power Dissipation
PD*1, *2
2.4
W
Junction Temperature
Tj
+125
°C
• Capable of downsizing a choke-coil due to IC's
high switching frequency (125kHz). (Compared with conventional Sanken devices)
Storage Temperature
Tstg
–40 to +125
°C
Thermal Resistance (junction to case)
θ j-c*2
18
°C/W
Thermal Resistance (junction to ambient air)
θ j-a*2
50
°C/W
• The output-voltage-variable type can vary its
output voltage from 1V to 14V because of its
low reference voltage (Vref) of 1V.
*1: Limited due to thermal protection.
*2: When mounted on glass-epoxy board 700cm2 (copper laminate area 30.8cm2).
• Wide Input Voltage Range (8 to 50V)
• Output ON/OFF available
• Built-in overcurrent and thermal protection
circuits
■Applications
• Onboard local power supplies
• OA equipment
• For stabilization of the secondary-side output voltage of switching power supplies
■Recommended Operating Conditions
Ratings
Parameter
Symbol
Unit
SPI-8010A
DC Input Voltage Range
VIN
(8 or Vo+3)*1 to 50
V
Output Voltage Range
VO
1 to 14
V
Output Current Range*2
IO
0.02 to 3.0*2
A
Operating Junction Temperature Range
Tjop
–30 to +125
°C
Operating Temperature Range
Top
–30 to +125
°C
*1: The minimum value of an input voltage range is the higher of either 8V or VO+3V.
*2: Please be sure to let the output current run more than 20 mA. When using by less than 20 mA, there is a possibility that the output voltage becomes unstable.
■Electrical Characteristics
(Ta=25°C)
Rating
Parameter
Symbol
SPI-8010A (Variable type)
min.
Reference Voltage
Line Regulation
Load Regulation
Temperature Coefficient of
Reference Voltage
Overcurrent Protection
Starting Current
Quiescent Circuit Current
Circuit Current at Output OFF
1.00
1.03
%
VIN=20V, IO=1A, VO=5V
250
Conditions
kHZ
VIN=12V, IO=1A
20
∆VOLINE
Conditions
40
mV
VIN=10 to 30V, IO=1A
10
∆VOLOAD
Conditions
30
mV
VIN=12V, IO=0.1 to 1.5A
∆VREF/∆Ta
mV/°C
±0.5
3.1
Conditions
Iq
Conditions
A
VIN=12V
7
mA
VIN=12V, IO=0A
Iq(off)
Conditions
400
µA
VIN=12V, VON/OFF=0.3V
Low Level Voltage
VSSL
0.5
Outflow Current at
Low Voltage
ISSL
50
Conditions
* Pin 4 is the CE/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. CE/SS-pin voltage can be changed with an opencollector drive circuit of a transistor. When using both the soft-start and ON/OFF functions
together, the discharge current from C4 flows into the ON/OFF control transistor. Therefore,
limit the current securely to protect the transistor if C3 capacitance is large.
The CE/SS pin is pulled up to the power supply in the IC, so applying the external voltage is
prohibited.
VSSL=0V
ICs
V
µA
SPI-8000A
SPI-8000A
SPI-8000A
4 CE/SS
4 CE/SS
4 CE/SS
C4
VO. ON/OFF
22
V
86
FOSC
IS
max.
VIN=12V, IO=1A
Conditions
Oscillation Frequency
Terminal
0.97
Eff
Efficiency
CE/SS
VREF
Conditions
Unit
typ.
Soft start
C4
Soft start
+VO. ON/OFF
SPI-8000A Series
■External Dimensions (HSOP16)
(Unit : mm)
1+0.1/-0.05
(Heatsink thickness)
10.5±0.2
9
1
8
10.5±0.3
2.5±0.2
2.75MAX
2.0+0.2/-0.08
16
0.25+0.15/-0.05
S
0.10
Pin Assignment
1.AGND
2.N.C
3.DGND
4.CE/SS
5.Reg
6.N.C
7.SWOUT
8.N.C
9.N.C
10.N.C
11.VIN
12.B.S
13.N.C
14.Comp
15.VREF
16.N.C
S
12.2±0.2
(Gate remains: Not included in dimensions)
(11)
8
(4.5)
7.5±0.2
(2)
1
16
9
1.27±0.25
Product Mass : Approx 0.86g
0.4+0.15/-0.05
■Block Diagram
SPI-8010A
VIN
UVLO
CE/SS
P.REG
OCP
CE/SS
BS
Boot REG
TSD
DRIVE
Reg
OSC
+
-
PWM
LOGIC
SWOUT
VREF
Comp
Amp
+
1V
GND
ICs
23
1-1-3 DC/DC Converter ICs
■Typical Connection Diagram
SPI-8010A
12
B.S
R1
L1
C3
11
VIN
VIN
SPI-8010A
SWOUT
V0
7
4
C1
D1 R2
CE/SS
+
C7
Reg Comp AGND
5
C4
14
C5
1
DGND VREF
+
C2
15
R3
3
C8
IREF
C6
GND
GND
C1: 220µF/63V
C2: 470µF/25V
C3: 0.1µF
C4: 1000pF
C5: 0.1µF
C6: 0.047µF
C7: 0.1µF
C8: 0.1µF
R1: 47Ω
L1: 47µH
D1: SPB-G56S
(Sanken)
Diode D1
• Be sure to use a Schottky-barrier diode for D1. If other diodes like fast recovery diodes are used, ICs may be destroyed because of the reverse voltage
generated by the recovery voltage or ON voltage.
Choke coil L1
• 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
overload or short-circuited load.
Capacitors C1, C2
• As large ripple currents flow through C1 and C2, use high-frequency and low-impedance capacitors aiming for switching-mode-power-supply use. Especially
when the impedance of C2 is high, the switching waveform may become abnormal at low temperatures. For C2, do not use a capacitor with an extremely low
equivalent series resistance (ESR) such as an OS capacitor or a tantalum capacitor, which may cause an abnormal oscillation.
Resistors R2, R3
• R2 and R3 are the resistors to set the output voltage. Set their values so that IREF becomes approx. 2mA. Obtain R2 and R3 values by the following formula:
R2=
VREF
(VOUT–VREF) (VOUT–1)
1
.=500(Ω)
=
(Ω), R3 =
=
.
IREF
2×10–3
IREF
2×10–3
To create the optimum operating conditions, place the components as close as possible to each other.
■Ta-PD Characteristics
3.00
Power Dissipation PD (W)
PD=VO • IO
2.50
θ j-a:41.7°C/W(30.8cm2)
θ j-a:47.6°C/W(8.64cm2)
Note 1: 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.
Note 2: Thermal design for D1 must be considered separately.
2.00
θ j-a:62.5°C/W(0.84cm2)
1.50
1.00
0.50
0
–30
0
25
50
75
100
Ambient Temperature Ta (°C)
24
ICs
100
VO
–1 –VF • IO 1–
ηχ
VIN
125
VO : Output voltage
VIN : Input voltage
IO : Output current
ηχ : Efficiency (%)
VF : Diode D1 forward voltage
SPB-G56S···0.4V(IO=2A)