spi-8010a an en

SPI-8010A
Application Note
Surface Molding Chopper type Switching Regulator IC
SPI-8010A
6th Edition October 2013
SANKEN ELECTRIC CO., LTD
SPI-8010A
---
Contents
---
1. General Description
1-1 Features
----------
3
1-2 Applications
----------
3
1-3 Type
----------
3
2-1 Package Information
----------
4
2-2 Ratings
----------
5
2-3 Circuit Diagram
----------
7
3-1 PWM Output Voltage Control
----------
9
3-2 Overcurrent Protection / Thermal Shutdown
----------
10
4-1 External Components
----------
11
4-2 Pattern Design Notes
----------
15
4-3 Operation Waveform Check
----------
16
4-4 Thermal Design
----------
17
5-1 Soft Start
----------
19
5-2 Output ON / OFF Control
----------
19
5-3 Controllable Output Voltage
----------
19
5-4 Reverse Bias Protection
----------
20
6. Typical Characteristics
----------
21
7. Terminology
----------
22
2. Specification
3. Operational Description
4. Cautions
5. Applications
2
SPI-8010A
1. General Description
The SPI-8010A is a chopper type switching regulator IC which is provided with various functions required for the
buck switching regulator and protection functions. A high speed, high accuracy and high efficiency switching
regulator of 250 KHz operating frequency can be composed. Since a package having a heat sink on the backside of
IC is used, thermal resistance can be significantly decreased
● 1-1 Features
-
Compact size and large output current of 3A
The maximum output current of 3A for the outline of HSOP 16
-
High efficiency of 86% (VIN = 20V / Vo / Io = 5V / 1A)
As the DMOS is used in the output stage, heat generation can be reduced and heat dissipation pattern can
be made smaller.
-
Reference oscillation by a built-in timing capacitor
No external capacitor for setting the oscillation frequency is required.
-
Built-in functions for overcurrent and thermal shutdown
The foldback type overcurrent protection and thermal shutdown circuit are built in.
(Automatic recovery type)
-
Soft start function (capable of ON/OFF output)
By adding an external capacitor, it is possible to delay the rise speed of the output voltage. ON/OFF
control of the output is also possible.
-
The output voltage can be adjusted by an external resistor.
By using 2 pieces of external resistors, the output voltage is variable in the range of +1V to + 14V.
●
1-2 Applications
For on-board local power supplies, power supplies for OA equipment, stabilization of secondary output voltage of
regulator and power supply for telecommunication equipment
●
1-3 Type
-
Type: Semiconductor integrated circuits (monolithic IC)
-
Structure: Resin molding type (transfer molding)
3
SPI-8010A
2. Specification
● 2-1 Package Information
1+0.1/-0.05
(Heat sink
thickness)
10.5±0.2
9
16
1.35±0.2
(between
backside and
frame root)
0 - 0.1
b
c
0.9±0.3
8
1
2.0+0.2/-0.08
2.75MAX
c
2.5±0.2
SK
8010A
10.5±0.3
a
0 - 8°
Extended A part
A part
0.25+0.15/-0.05
0.10
S
S
12.2±0.2
(excluded remaining gate)
a. Type number
(11)
b. Lot number (three-digit)
1
1st letter: Last digit of year
(2)
8
2nd letter: Month
(4.5)
7.5±0.2
1 to 9: Jan. to Sept.
O for Oct.
N for Nov.
D for Dec.
16
9
0.4+0.15/-0.05
1.27±0.25
rd
3 letter: Assembly span
1 – 5: Arabic numerical
c. Control number (five-digit)
Pin Assignment
1.AGND
9.N.C
2.N.C
10.N.C
3.DGND
11.VIN
4.CE/SS
12.BS
5.Reg
13.N.C
6.N.C
14.Comp
7.SWout
15.VREF
8.N.C
16.N.C
4
SPI-8010A
● 2-2 Ratings
Absolute Maximum Rating
Parameter
Symbol
Rating
Unit
Input Voltage
VIN
53
V
Allowable Power Dissipation
Pd
2.4
W
Junction Temperature
Tj
125
°C
Storage Temperature
Tstg
-40 - 125
°C
θj-c
18
°C /W
θj-a
41.7
°C /W
Thermal Resistance
(Between Junction and case)
Thermal Resistance
(Between Junction and
Condition
Glass epoxy board: 7000mm2
(Copper foil area in package: 3080mm2)
Glass epoxy board: 7000mm2
(Copper foil area in package: 3080mm2)
Glass epoxy board: 7000mm2
(Copper foil area in package: 3080mm2)
ambient)
Recommended operation conditions
Ratings
Parameter
Symbol
Unit
MIN
MAX
Input Voltage
VCC
8 or VO +3
50
V
Output Voltage
Vo
1
14
V
Output Current *1
IOUT
0.02
3
A
Junction Temperature in Operation
Tjop
-30
125
°C
Operation Temperature
Top
-30
125
°C
Conditions
*1: It is strongly recommended to apply over 20mA on output current. It may cause unstable output voltage if output
current is less than 20mA.
5
SPI-8010A
Electrical Characteristics
(Ta=25°C)
Ratings
Parameter
Setting Reference Voltage
Output Voltage Temperature
Symbol
VREF
Unit
MIN
TYP
MAX
0.97
1.00
1.03
Measurement
Conditions
V
VREF/T
±0.5
mV/°C
Eff
86
%
VIN=12V, IO=1A
Coefficient
Efficiency
VIN=20V, IO=1A,
VO=5V
Operation Frequency
Line Regulation
fosc
250
VLine
20
kHz
40
mV
VIN=12V, IO=1A
VIN=10 - 30V,
IO=1A
Load Regulation
VLoad
10
30
mV
VIN=12V,
IO=0.1 - 1.5A
Overcurrent Protection
IS
3.1
A
VIN=12V
Start Current
Circuit Current
Iq
7
mA
in Non-operation 1
Circuit Current
Iq(off)
400
μA
in Non-operation 2
Low Level
VIN=12V, IO=0A
VIN=12V
VON/OFF=0.3V
VSSL
0.5
V
ISSL
50
μA
Voltage
CE/SS
terminal
Flow-out Current
at Low Level
VSSL=0V
Voltage
6
SPI-8010A
● 2-3 Circuit Diagram
2-3-1 Internal Equivalent Circuit
VIN
SPI-8010A
11
C1
5
VIN
UVLO
4
2
P.REG
OCP
CE/SS CE/
SS
C4
Boot
REG
TSD
BS
6
12
R1
DRIVE
5
3
Reg
C3
4
PWM
LOGIC
OSC
7
L1
D1
VREF
Comp
8
Amp
1V
C6
AGND
DGND
1
1
1
C8
C2
R2
7
VOUT
SWOUT
C5
14
C7
C9
15
R3
3
2-3-2 Typical Connection Diagram
12
B.S
11
VIN
4
C1
C7
C3
VIN
GND
SPI-8010A
14
C5
1
C1: 220μF/63V
L1
SWOUT
VO
7
CE/SS
Reg Comp AGND DGNDVREF
5
C4
R1
3
D1 R2
C3: 0.1μF
C9
C2
15
R3
C2: 470μF/25V
C8
IREF
C4: 1000pF
C5: 0.1μF
C6
GND
C6: 0.047μF
C7: 0.1μF
C8: 0.1μF
C9: 6800pF
R1: 47Ω
L1: 47μH
D1: SPB-G56S
(SANKEN)
7
SPI-8010A
2-3-3 Main Components List
Component
Spec
Recommended materials
C1
220μF / 63V / Electrolytic capacitor
EMVY630GTR221MLHoS (Nippon Chemi-Con)
C2
470μF / 25V / Electrolytic capacitor
UUD1E471MNR1GS (nichicon)
C3, C5
0.1μF / 10V / Ceramic capacitor
GRM31BR11A105MA01B (MURATA)
C4
0.1μF / 50V / Ceramic capacitor
GRM21BR11H104MA01B (MURATA)
C6
0.1μF / 50V / Ceramic capacitor
GRM21BR11H104MA01B (MURATA)
C7, C8
0.1μF / 50V / Ceramic capacitor
GRM21BR11H104MA01B (MURATA)
C9
0.1μF / 50V / Ceramic capacitor
GRM21BR11H104MA01B (MURATA)
L1
47μH / Inductor
SLF12575T-470M2R7 (TDK)
D1, D2
1.5A / 60V / Schottky barrier diode
SPB-G56S (Sanken)
R1
47Ω
-
R2
2kΩ (VO = 5V)
-
R3
500Ω
-
8
SPI-8010A
3. Operational Description
●
3-1 PWM Output Voltage Control
In the SPI-8010A series, the output voltage is controlled by the PWM system and the IC integrates the PWM
comparator, oscillator, error amplifier, reference voltage, output transistor drive circuit etc. The triangular wave
output (≈ 250KHz) from the oscillator and the output of the error amplifier are given to the input of the PWM
comparator. The PWM comparator compares the oscillator output with the error amplifier output to turn on the
switching transistor for a time period when the output of the error amplifier exceeds the oscillator output.
PWM Control Chopper Type Regulator Basic Configuration
VOUT
Switching Transistor
スイッチングトランジスタ
VIN
PWM Comparator
PWMコンパレータ
D1
C2
Drive Circuit
ドライブ回路

Error
Amplifier
誤差増幅器
Oscillator
発振器
Reference
基準電圧
Voltage
The error amplifier output and the oscillator output are compared by the PWM comparator to generate the
drive signal of rectangular wave and to drive the switching transistor.
On the assumption that the output voltage attempts to rise, the output of the error amplifier is decreased, because the
error amplifier is of inverting type. When the output of the error amplifier is decreased, the time period where it
exceeds the triangular wave of the oscillator is decreased to shorten the ON time of the switching transistor and as a
result, the output voltage is maintained constant.
As described above, the output voltage is controlled by varying the ON time of the switching transistor with the
switching frequency fixed (the higher is VIN, the shorter is the ON time of the switching transistor.)
PWM Comparator Operation Diagram
Oscillator
発振器出力
Output
Error Amplifier
誤差増幅器出力
ON
OFF
Output
スイッチングトランジスタ出力
Switching Transistor
Output
The rectangular wave output of the switching transistor is smoothed by the LC low pass filter composed of a choke
coil and a capacitor to supply stabilized DC voltage to the load.
9
SPI-8010A
●
3-2 Overcurrent Protection / Thermal Shutdown
The SPI-8010A includes the foldback type overcurrent protection circuit. The overcurrent protection circuit detects
the peak current of a switching transistor and when the peak current exceeds the set value, the ON time of the
transistor is compulsorily shortened to limit the current by lowering the output voltage. When the overcurrent
condition is released, the output voltage will be automatically restored.
Output Voltage Characteristic on Overcurrent
出力電圧
Output Voltage
Output出力電流
Current
The thermal shutdown circuit detects the semiconductor junction temperature of the IC and when the junction
temperature exceeds the set value, the output transistor is stopped and the output is turned OFF. When the junction
temperature drops from the set value for overheat protection by around 15°C, the output transistor is automatically
restored.
* Note for thermal shutdown characteristic
This circuit protects the IC against overheat resulting from the instantaneous short circuit, but it should be noted that
this function does not assure the operation including reliability in the state that overheat continues due to long time
short circuit.
Output Voltage Characteristic on Thermal Shutdown
出力電圧
Output Voltage
Restoration setting
Temperature
復帰設定温度
Protection Setting
Temperature
保護設定温度
接合温度
Junction Temperature
10
SPI-8010A
4. Cautions
● 4-1 External Components
4-1-1 Choke coil L
The choke coil L1 is one of the most important components in the chopper type switching regulator. In order to
maintain the stable operation of the regulator, such dangerous state of operation as saturation state and operation at
high temperature due to heat generation must be avoided.
The following points should be taken into consideration for the selection of the choke coil.
a) The choke coil should be fit for the switching regulator.
The coil for a noise filter should not be used because of large loss and generated heat.
b) The inductance value should be appropriate.
The larger is the inductance of the choke coil, the less is the ripple current flowing across the choke coil, and the
output ripple voltage drops and as a result, the overall size of the coil becomes larger.
On the other hand, if the inductance is small, the peak current flowing across the switching transistor and diode is
increased to make the ripple voltage higher and this operation state is not favorable for maintaining the stable
operation.
Large Inductance
Small Ripple Voltage/ Current
The larger is the inductance, the smaller will be
the ripple current/voltage. But the outer size of
the coil becomes larger.
Small Inductance Large Ripple Voltage/ Current
The smaller is the inductance, the larger will be
the ripple current/voltage.
Although the outer size of the coil is smaller, the
operation is likely to be unstable.
The inductance value shown in the specifications should be considered as a reference value for the stable operation
and the appropriate inductance value can be obtained by the following equation.
ΔIL shows the ripple current value of the choke coil and the lower limit of inductance is set as described in the
following.
-
In the case that the output current to be used is nearly equal to the maximum rating (3A) of the SPI-8010A:
output current × 0.2- 0.3
-
In the case that the output current to be used is approximately 1A or less: output current × 0.5 - 0.6
L
(Vin  Vout )  Vout
IL  Vin  f
---(1)
11
SPI-8010A
For example, where VIN = 25V, VOut = 5V, ΔIL = 0.35A, frequency = 250kHz,
L1 
(25  5)  5
≒ 45.7uH
0.35  25  25010 3
As shown above, the coil of about 47μH may be selected.
c) The rated current shall be met.
The rated current of the choke coil must be higher than the maximum load current to be used. When the load current
exceeds the rated current of the coil, the inductance is sharply decreased to the extent that it causes saturation state at
last. Please note that overcurrent may flow since the high frequency impedance becomes low.
d) Noise shall be low.
In the open magnetic circuit core which is of drum shape, since magnetic flux passes outside the coil, the peripheral
circuit may be damaged by noise. It is recommended to use the toroidal type, EI type or EE type coil which has a
closed magnetic circuit type core as much as possible.
4-1-2 Input Capacitor C1
The input capacitor is operated as a bypass capacitor of the input circuit to supply steep current to the regulator
during switching and to compensate the voltage drop of the input side. Therefore, the input capacitor should be
connected as close as to the regulator IC.
In addition, in the case that the smoothing capacitor of the AC rectifier circuit is located in the input circuit, the input
capacitor may be also used as a smoothing capacitor, but similar attention should be paid.
The selection of C1 shall be made in consideration of the following points:
a) The requirement of withstand voltage shall be met.
b) The requirement of the allowable ripple voltage shall be met.
Current Flow of C1
Current
Waveform of C1
C1電流波形
IIN
VIN
5. V
1.V
ININ
Ripple
Current
リップル電流
0
Iv
Ip
C1
D
Ton
Ton
T
T
The ripple current of the input capacitor is
increased in accordance with the increase of the
load current.
12
SPI-8010A
If the withstanding voltages or allowable ripple voltages are exceeded or used without derating, it is in danger of
causing not only the decreasing the capacitor lifetime (burst, capacitance decrease, equivalent impedance increase,
etc) but also the abnormal oscillations of regulator.
Therefore, the selection with sufficient margin is needed.
The effective value of ripple current flowing across the input capacitor can be calculated by the following equation:
Irms  1.2 
Vo
 Iout
Vin
--(2)
For instance, where Io=3A, VIN=20V, Vo=5V,
Irms  1.2 
5
 3  0.9 A
20
Therefore, it is necessary to select the capacitor with the allowable ripple current of 0.9A or higher.
4-1-3 Output Capacitor C2
The output capacitor C2 composes a LC low pass filter together with a choke coil L1 and functions as a rectifying
capacitor of switching output. The current equivalent to the pulse current ΔIL of the choke coil current is charged and
discharged in the output capacitor. Therefore, it is necessary to meet the requirements of withstand voltage and
allowable ripple current with sufficient margin like the input capacitor.
The following points should be taken into consideration.
Current Flow of C2
IL
Vout
L1
Current Waveform of C2
ESR
C2電流波形
Io
Ripple
Current
リップル電流
0
RL
⊿IL
The ripple current of the output capacitor is
equal to the ripple current of the choke coil and
does not vary even if the load current increases
or decreases.
C2
a) Allowable Ripple Current
The ripple current effective value of the output capacitor is calculated by the equation.
Irms 
IL
2 3
---(3)
When ΔIL = 0.5A,
Irms 
0.5
≒ 014
. A
2 3
Therefore a capacitor having the allowable ripple current of 0.14A or higher is required.
The output ripple voltage is determined by a product of the pulse current ΔIL (=C2 discharge and charge current) of
13
SPI-8010A
the choke coil current and the ESR
Vrip  IL  C2ESR
---(4)
b) DC equivalent series resistance (ESR)
When the ESR is too large, it causes abnormal oscillation due to increase of ripple voltage. On the other hand,
when the ESR is too small, it causes insufficient phase margin.
The output ripple voltage is determined by a product of the pulse current ΔIL (=C2 discharge and charge current) of
the choke coil current and the ESR, and the output ripple voltage which is 0.5 - 1% of the output voltage (for
example, 25mV where 0.5% at VOUT = 5V.) is good for the stable operation. Please refer to the equations (4) and
(5) to obtain the output ripple voltage. It should be noted that the ESR is changeable subject to temperature and it is
especially decreased at high temperature.
Vrip 
Vin  Vout Vout ESR ---(5)
L  Vin  f
Vrip  IL  ESR ---(6)
However, if the ESR of the output capacitor is too low (10 - 20mΩ or lower), the phase margin within the feedback
loop of the regulator will be short to make the operation unstable. Therefore, it is not appropriate that a tantalum
capacitor or a laminated ceramic capacitor is used for the output capacitor as an independent component. However,
connecting a tantalum capacitor or a laminated ceramic capacitor in parallel with an electrolytic capacitor is effective
in reducing the output ripple voltage only when it is used at low temperature (< 0°C).
In addition, in order to further decrease the ripple voltage, as shown below, it is also effective to add one stage of the
LC filter to form the π type filter.
L1
L2
7.SW
4.SWOUT
11.V
5.VININ
SPI-8010A
SI-8010GL
1,3.GND
1,GND
L2: 20μH
15.V
REF
8.VREF
D1
C2
C4
C4: 200μF
The abnormal oscillation can be caused unless the output voltage detection point (wiring to the Vos terminal) is
placed before the second stage filter if the second stage filter is added. Therefore, the care should be taken.
It should be noted that the operating stability is more influenced by the ESR than the capacitance as described above
if the requirements of withstand voltage and allowable ripple current are met.
4-1-4 Flywheel Diode D1
The flywheel diode D1 is to discharge the energy which is stored in the choke coil at switching OFF.
For the flywheel diode, the Schottky barrier diode must be used. If a general rectifying diode or fast recovery diode is
used, the IC may be destroyed by applying reverse voltage due to the recovery and ON voltage.
14
SPI-8010A
In addition, since the output voltage from the SWOUT terminal (pin 7) of the SPI-8010A series is almost equivalent to
the input voltage, the flywheel diode with the reverse withstand voltage of the input voltage × 1.2 or higher should be
used.
●
4-2 Pattern Design Notes
4-2-1 High Current Line
Since high current flows in the bold lines in the connection diagram, the pattern should be as wide and short as
possible.
L1
11,VIN
VIN
7.SWOUT
VOUT
SPI-8010A
C1
4.SS
1,3.GND
15.VOS
GND
D1
C2
GND
4-2-2 Input / Output Capacitor
The input capacitor C1 and the output capacitor C2 should be connected to the IC as close as possible. If the
rectifying capacitor for AC rectifier circuit is on the input side, it can be used as an input capacitor. However, if it is
not close to the IC, the input capacitor should be connected in addition to the rectifying capacitor.
Since high current is discharged and charged through the leads of input/output capacitor at high speed, the leads
should be as short as possible.
A similar care should be taken for the patterning of the capacitor.
C1,C2
Improper Pattern Example
C1,C2
Proper Pattern Example
4-2-3 Sensing Terminal
The output voltage sensing terminal Vos shall be connected near the output capacitor C2 as much as possible. If it is
connected far from C2, it should be noted that abnormal oscillation may happen due to the low regulation and
increased switching ripple.
15
SPI-8010A
●
4-3 Operation Waveform Check
It can be checked by the waveform between the pin 7-1 and 3 (SWOUT - GND waveform) of the SPI-8010A whether
the switching operation is normal or not.
The examples of waveforms at normal and abnormal operations are shown below:
1. Normal Operation (continuous area)
2. Normal Operation (discontinuous area)
3. When C1 is far from IC
4. When C2 is far from IC
The continuous area is an area where the DC component of the triangular wave is superimposed on the current
flowing across the choke coil and the discontinuous area is an area where the current flowing across the choke coil is
intermittent (a period of zero current may happen.) because the current flowing across the choke coil is low.
Therefore, when the load current is high, the area is a continuous area and when the same current is low, the area is a
discontinuous area.
In the continuous area, the switching waveform is formed in the normal rectangular waveform (waveform 1) and in
the discontinuous area, damped oscillation is caused in the switching waveform (waveform 2), but this is a normal
operation without any problem.
In the meantime, when the IC is far from C1 and C2, jitter which disturbs the ON - OFF time of switching will
happen as shown in the waveforms (3, 4). As described above, C1 and C2 should be connected close to the IC.
16
SPI-8010A
●
4-4 Thermal Design
4-4-1 Calculation of Heat Dissipation
The relation among the power dissipation Pd of regulator, junction temperature Tj, case temperature Tc, board
temperature Tfin and ambient temperature Ta is as follows:
Pd (Power
dissipation)
Pd(損失)
Tj:
Temperature (125°C max)
Tj Junction
ジャンクション温度(125℃MAX)
チップ
Chip
Θjc:
Thermal Resistance (Junction – Case) 5.5°C / W
θ jc(接合-ケース間熱抵抗)
5.5℃/W
ケース
Case
Tc:
temperature (internal frame temperature)
Tc Case
ケース温度(内部フレーム温度)
Board
基板
Θi:
Thermal Resistance (Case - Heat sink) 0.4 – 0.6°C / W
θ i(ケース-放熱器間熱抵抗)
0.4~0.6℃/W
Tfin Board
放熱器温度
Tfin:
temperature
Θfin:
Board Thermal resistance
θ fin(基板熱抵抗)
Ta Ambient
周囲温度temperature
Ta:
Tj  Tc
--(7)
jc
Tj  Tfin
--(8)
Pd 
jc  i
Tj  Ta
--(9)
Pd 
jc  i  fin
Pd 
The TjMAX is an inherent value for each product, therefore it must be strictly observed.
For this purpose, it is required to design the board pattern in compliance with PdMAX, TaMAX (determination of
θfin).
The heat derating graphically describes this relation.
The designing of the heat sink is carried out by the following procedure:
1) The maximum ambient temperature Ta MAX in the set is obtained.
2) The maximum power dissipation PdMAX is obtained by varying input/ output conditions.
 100 
Vo 

Pd  Vo  Io
 1  Vf  Io1 

 Vin 
 x

---(10)
* ηx= efficiency (%), Vf= diode forward voltage
3) The size of heat sink is determined from the intersection of the heat derating.
The required thermal resistance of the heat sink can be also calculated. The thermal resistance required for the heat
sink is calculated by the following equation:
17
SPI-8010A
i  fin 
Tj  Ta
 jc
Pd
---(11)
An example of heat calculation for using SPI-8010A under the conditions of VIN = 10V, VOUT = 5V, IOUT = 3A and
Ta = 85°C is shown below. Where efficiency η = 87% , Vf = 0.5V from the typical characteristics,
5
 100 

Pd  5  3  
 1  0.5  3  1   ≒1.49W
 87

 10 
125  85
i  fin 
 18 ≒ 8.85゚C / W
1.49
As a result, the heat sink with the thermal resistance of 9°C /W or less is required. As described above, the thermal
resistance of board is determined, but the derating of 10 - 20% or more is used. Actually, heat dissipation effect
significantly changes depending on the difference in component mounting. Therefore, board temperature or case
temperature at mounted should be checked.
4-4-2 Installation to Board
Connection of GND pattern to the back side heat sink
The SPI-8010A adopts a package having a heat sink on the backside of IC. In order to enhance the heat dissipation
effect, it is recommended to connect the GND pattern to the back side heat sink.
18
SPI-8010A
5. Applications
● 5-1 Soft Start
When a capacitor is connected to No.4 terminal of the SPI-8010A, soft start operation can be made for the purpose
of providing delay time from the application of input voltage to the rise of output voltage. By means of this operation,
the state of high input voltage is realized prior to the operation of a regulator.
In the case of the buck converter type switching regulator, as the input voltage becomes higher the input current is
reduced, therefore the operation can be started with less current. In the case of the actual equipment, more or less
variation takes place because of the influence from the rise time of input power supply.
The C4 should be used with 4700 pF or less.
SPI-8010A
Vin
4
Td 
Vo
C4
3.2  C 4
( Sec)
15  106
Td
●
5-2 Output ON / OFF Control
The output ON-OFF control is possible using No.4 terminal, CE/ SS terminal. The output is turned OFF when the
terminal 4 voltage falls to low by switch such as open collector. It is possible to use the soft start together.
Since CE/ SS terminal has been already pulled up in the IC inside, no voltage shall be applied from the external side.
SPI-8010A
4.CE/SS
C3
SS+ON/OFF
●
5-3 Controllable Output Voltage
R2 and R3 are resistors for setting the output voltage. It should be set in a manner that IREF is around 2mA.
The equation by which the values of R2 and R3 can be calculated is as follows:
V  VREF   VOUT  1 ,R3  VREF  1 ≒ 500
R 2  OUT
I REF
2  103
I REF 2  103
19
SPI-8010A
●
5-4 Reverse Bias Protection
A diode for reverse bias protection is required between input and output when the output voltage is higher than the
input terminal voltage, such as in battery chargers.
SPI-8000A
20
SPI-8010A
6. Typical Characteristics
Efficiency
Overcurrent Protection Characteristics
1.2
100
Efficiency η [%]
90
Io=3A
1A
Vo=5V
0.5A
80
Io=3A
70
1A
Io=3A
1A
Vo=1.8V
0.5A
60
Output Voltage VO [V]
Vo=14V
1.0
0.8
0.6
0.4
VIN= 8V
12V 20V 30V
0.2
0.5A
0
10
20
30
40
Input Voltage VIN [V]
0
50
0
Output Voltage Rising *Load = C.R
1.0
Output Voltage VO [V]
Output Voltage VO [V]
IO=0.02A 1A 3A
0.8
0.6
0.4
5
1.0
0.8
0.6
TSD OFF
TSD ON
0.4
0.2
0.2
0
0
0
2
6
8
Input Voltage VIN [V]
4
10
Load Regulation Characteristics
1.03
Efficiency
η [%]
Operating Frequency
Freq [kHz]
20V
30V
0.98
0
1.0
2.0
Output Current IO [A]
200
1.015
Freq
250
200
VIN=8V
12V
0.99
100
150
Ambient Temperature Ta [°C]
Temperature Characteristics VIN=12V, IO=1A
1.01
1.00
50
300
1.02
Output Voltage VO [V]
2
3
4
Output Current IO [A]
Thermal Shutdown Protection VIN=12V, IO=0.02A
1.2
1.2
0.97
1
3.0
1.01
1.005
150
VO
100
1
0.995
Output Voltage VO [V]
50
η
50
-50
0.99
0
50
100
Ambient Temperature Ta [°C]
150
21
SPI-8010A
7. Terminology
8.用語解説
-
Jitter
It is a kind of abnormal switching operations and is a phenomenon that the switching pulse width varies in spite of
the constant condition of input and output. The output ripple voltage peak width is increased when a jitter occurs.
-
Recommended Operation Conditions
It shows the operation conditions required for maintaining normal circuit functions. It is required to meet the
conditions in actual operations.
-
Absolute Maximum Ratings
It shows the destruction limits. It is required to take care so that even one item does not exceed the standard value for
a moment during instantaneous or normal operation.
-
Electrical Characteristics
It is the specified characteristic value in the operation under the conditions shown in each item. If the operating
conditions are different, it may be out of the specifications.
-
PWM (Pulse Width Modulation)
It is a kind of pulse modulation systems. The modulation is achieved by changing the pulse width in accordance with
the variation of modulation signal waveform (the output voltage for chopper type switching regulator).
-
ESR (Equivalent Series Resistance)
It is the equivalent series resistance value of a capacitor. It operates in a similar way to the resistor series-connected
to the capacitor.
22
SPI-8010A
Caution/ Warning
・The contents of this document are subject to change without prior notice for improvement etc. Please
make sure that this is the latest information prior to the use of the products.
・Application and operation examples described in this document are quoted for the sole purpose of
reference for the use of the products herein and Sanken can assume no responsibility for any
infringement of industrial property rights, intellectual property rights or any other rights of Sanken or
any third party which may result from its use.
・When using the products herein, the applicability and suitability of such products for the intended
purpose object shall be reviewed at the user responsibility.
・Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of
failure and defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are
requested to take, at their own risk, preventative measures including safety design of the equipment or
systems against any possible injury, death fires of or damages to the society due to device failure or
malfunction.
・Sanken products listed in document are designed and intended for the use as components in general
purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication
equipment, measuring equipment, etc.). Please sign this document prior to the use of the products herein.
When considering the use of Sanken products in the applications where higher reliability is required
(transportation equipment, and its control systems, traffic signal control systems or equipment, fire /
crime alarm systems, various safety devices, etc.), please contact your nearest Sanken sales
representative to discuss, and then sign this document prior to the use of the products herein. The use of
Sanken products without the written consent of Sanken in the applications where extremely high
reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is
strictly prohibited.
・Anti radioactive ray design is not considered for the products listed herein.
・The contents of this brochure document shall not be transcribed nor copied without our written consent.
23