SANKEN SI

SI-8008HD
DC-to-DC Step-Down Converter
Features and Benefits
Description
▪ 5.5 A output current supplied in a small, surface mount
power package
▪ High efficiency: 83% at VIN = 15 V, IO = 3.0 A,VO = 5 V
▪ Requires only seven external components (optional soft
start requires an additional capacitor)
▪ Oscillation circuit built-in (frequency 150 kHz typical)
▪ Constant-current mode overcurrent protection circuit and
overtemperature protection circuit built-in
▪ Soft start function built-in (can be implemented as an
on/off function; output-off state at low level)
▪ Low current consumption during output-off state
The SI-8008HD DC voltage regulator is a DC-to-DC buck
convertor that attains an oscillation frequency of 150 kHz,
and has an integrated miniaturized choke coil, allowing it to
serve as a small, high efficiency power supply in a compact
TO-263 package.
Package: TO263-5
Applications include:
▪ DVD recorder
▪ FPD TV
▪ Telecommunications equipment
▪ Office automation equipment, such as printers
▪ On-board local power supply
▪ Output voltage regulator for second stage of SMPS
(switched mode power supply)
The internal switching regulator function provides high
efficiency switching regulation without any need for adjustment.
The device requires only six external support components. The
optional soft start function requires an additional capacitor.
Optional on/off control can be performed using a transistor.
The SI-8008HD includes overcurrent and overtemperature
protection circuits.
Not to scale
Functional Block Diagram
VIN
1 IN
C1
SW
PReg
C4
C3
On/Off
Soft Start
Latch and
Driver
C2
R1
Osc
Comparator
Overtemperature
Protection
Error
Amplifier
GND
3
ADJ
4
R2
Reference
Voltage
27469.059
VOU
L1
Di
FMB-G16L
(Sanken)
Overcurrent
Protection
Reset
5 SS
2
SI-8008HD
DC-to-DC Step-Down Converter
Selection Guide
Part Number
Output Voltage
Adjustable Range
(V)
Efficiency,
Typ.
(%)
Input Voltage,
Max.
(V)
Output Current,
Max.
(A)
Packing
SI-8008HD-TL
0.8 to 24
83
40
5.5
800 pieces per reel
Absolute Maximum Ratings
Characteristic
Symbol
Remarks
DC Input Voltage
VIN
Power Dissipation
PD
Mounted on 40 mm × 40 mm exposed copper area on 40 mm
× 40 mm glass-epoxy PCB; limited by internal overtemperature
protection.
Junction Temperature
TJ
Internal overtemperature protection circuit may enable when TJ ≥
130°C. During product operation, recommended TJ ≤ 125°C.
Storage Temperature
Tstg
Thermal Resistance (junction-to-case)
RθJC
Mounted on 40 mm × 40 mm exposed copper area on 40 mm ×
40 mm glass-epoxy PCB.
Thermal Resistance (junction-to-ambient air)
RθJA
Mounted on 40 mm × 40 mm exposed copper area on 40 mm ×
40 mm glass-epoxy PCB.
Rating
Units
43
V
3
W
–40 to 150
°C
–40 to 150
°C
3
°C/W
33.3
°C/W
Recommended Operating Conditions*
Characteristic
Symbol
DC Input Voltage Range
VIN
DC Output Voltage Range
VO
DC Output Current Range
Remarks
VIN (min) is the greater of 4.5 V or VO+3 V.
VIN ≥ VO + 3 V; to be used within the allowable package
power dissipation characteristics (refer to Power Dissipation
chart).
IO
Operating Junction Temperature Range
TJOP
Operating Temperature Range
TOP
To be used within the allowable package power dissipation
characteristics (refer to Power Dissipation chart).
Min.
Max.
Units
See
remarks
40
V
0.8
24
V
0
3.5
A
–30
100
°C
–30
85
°C
*Required for normal device functioning according to Electrical Characteristics table.
All performance characteristics given are typical values for circuit or
system baseline design only and are at the nominal operating voltage and
an ambient temperature, TA, of 25°C, unless otherwise stated.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
2
SI-8008HD
DC-to-DC Step-Down Converter
ELECTRICAL CHARACTERISTICS1, valid at TA = 25°C, VO = 5 V (adjusted), R1 = 4.2 kΩ, R1 = 0.8 kΩ
Characteristic
Symbol
Reference Voltage
VADJ
Reference Voltage Temperature Coefficient
∆VADJ /∆T
Min.
Typ.
Max.
Units
0.784
0.800
0.816
V
VIN = 15 V, IO = 0.2 A, TC = 0 to 100 °C
–
±0.1
–
mV/°C
η
VIN = 15 V, IO = 3 A
–
83
–
%
fO
Efficiency2
Operating Frequency
Test Conditions
VIN = 15 V, IO = 0.2 A
VIN = 15 V, IO = 3 A
–
150
–
kHz
Line Regulation
VLine
VIN = 10 to 30 V, IO = 3 A
–
60
80
mV
Load Regulation
VLoad
VIN = 15 V, IO = 0.2 to 5.5 A
Overcurrent Protection Threshold Current
IS
VIN = 15 V
SS Terminal On/Off Operation Threshold Voltage
VSSL
SS Terminal On/Off Operation Outflow Current
ISSL
Quiescent Current 1
Iq
Quiescent Current 2
Iq(off)
–
20
50
mV
5.6
6.5
7.5
A
–
–
0.5
V
VSSL = 0 V
–
10
30
μA
VIN = 15 V, IO = 0 A
–
6
–
mA
VIN = 15 V, VSS = 0 V
–
200
400
μA
1Using
circuit shown in Typical Application Circuit diagram.
2Efficiency is calculated as: η(%) = ([V × I ] × [V × I ]) × 100.
O
O
IN
IN
Pin-out Diagram
Terminal List Table
Name
Number
Function
IN
1
Supply voltage
SW
2
Regulated supply output
GND
3
Ground terminal
ADJ
4
Terminal for resistor bridge feedback
The SS terminal is used to enable soft start and to control on/off operation of the IC output,
VO (see figure 2). If neither soft start nor on/off control is used, leave pin open.
SS
1
2
3
4
5
To enable soft start, connect a capacitor between SS and ground. To control on/off
operation, connect an NPN bipolar transistor, in a TTL open collector output configuration,
between the SS terminal and GND. Turn off is done by decreasing VSSL below its rated
level.
When both soft start and VO on/off are used, a protection measure such as current limiting
is required because, if the capacitance of C3 large, the discharge current of C3 flows
across the transistor for on/off operation. Because a pull-up type resistor is provided inside
the IC, no external voltage can be applied.
5
SI-8008HD
SI-8008HD
SI-8008HD
SS
5
SS
5
SS
5
System
TTL
C3
System
TTL
(a)
VO on/off
control only
(b)
Soft start
only
C3
(c)
VO on/off and
soft start control
Figure 2. Alternative configurations for SS pin. If neither soft start nor VO on/off is required, the SS pin is left open.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
3
SI-8008HD
DC-to-DC Step-Down Converter
Performance Characteristics
at TA = 25°C, VO = 5 V adjusted, , R1 = 4.2 kΩ, R2 = 0.8 kΩ
90
8V
5.06
15 V
40 V
30 V
5.02
40 V
Load Regulation:
5.00
Output Voltage
versus
4.98
Output Current
70
30 V
20 V
VO (V)
η (%)
Efficiency versus
Output Current
VIN
5.04
80
VIN
60
10 V
4.96
50
40
8V
4.94
0
1
2
3
4
5
4.92
6
0
1
2
IO (A)
3
IO (A)
4
5
6
6
6.00
0A
8V
3A
4.00
4A
5.5 A
4
Overcurrent
Protection:
Output Voltage
versus
Output Current
3.00
2.00
VIN
10 V
15 V
3
20 V
2
30 V
IO
1.00
1
0
0
0
1
2
3
4
5
VIN (V)
6
7
8
40 V
0
2
4
IO (A)
6
8
6
OTP On
5
Overtemperature
Protection:
Output Voltage versus
Junction Temperature
VIN = 15 V, IO = 10 mA
4
VO (V)
VO (V)
Low Voltage
Behavior:
Output Voltage
versus
Supply Voltage
5
1A
2A
VO (V)
5.00
3
2
1
OTP Off
0
0
20
40
60
80 100
TJ (°C)
120
140
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
160
180
4
SI-8008HD
DC-to-DC Step-Down Converter
Thermal Performance Characteristics
The application must be designed to ensure that the TJ(max)
of the device is not exceeded during operation. To do so, it is
necessary to determine values for maximum power dissipation,
PD(max), and ambient temperature, TA(max).
Power Dissipation versus Ambient Temperature
TJ(max) = 125°C; Mounted on glass-epoxy PCB (40 mm × 40 mm),
with varying exposed copper areas
3.5
Cu Area: 1600 mm2
RθJA = 33.3°C/W
The relationships of TJ, PD, TA, and case temperature, TC, are as
shown in the following formulas:
PD =
TJ – TC
RθJC
and
PD =
TJ – TA
RθJA
3.0
Cu Area: 800 mm2
RθJA = 37°C/W
.
2.5
PD can be calculated from input values:
⎞
⎟⎟
⎠
Cu Area: 400 mm2
RθJA = 44°C/W
2.0
PD (W)
⎛ 100 ⎞
⎛ V
− 1⎟⎟ − VF ⋅ I O ⎜⎜1 − O
PD = VO ⋅ I O ⎜⎜
⎝ Hx
⎠
⎝ VIN
Cu Area: 100 mm2
RθJA = 53°C/W
1.5
where:
VO is output voltage in V,
1.0
IO is output current in A,
ηx is IC efficiency in percent (varies with VIN and IO; refer to
efficiency performance curves for value), and
VF is forward voltage for the input diode, Di. In these tests, the
Sanken FMB-G16L was used, at 0.55 V. For application design,
obtain thermal data from the datasheet for the diode.
PD is substantially affected by the heat conductance properties of
the application, in particular any exposed copper area on the PCB
where the device is mounted. The relationships of PD, TA, and
copper area is represented in the Power Dissipation chart.
RθJA for a given copper area can be determined form the Device
Thermal Resistance chart. This can be substituted into the formula
above to determine the TJ (max) allowable in the application.
Generally, more than 10% to 20% derating is required.
0.5
0
–25
50
75
100
125
Glass-epoxy PCB, 40 mm × 40 mm
55
50
45
40
35
30
0
200
400
600
800
1000
1200
1400
1600
1800
Copper Area (mm2)
Power Dissipation versus Output Current
PD(W)
And analyzing the results using the following formula:
TJ = PD × RθJC + TC ,
25
Device Thermal Resistance versus Exposed Copper Area on PCB
Because the heat dissipation capacity of the copper area depends
substantively on how it is used in the actual application, thermal
characteristics of the application must be confirmed by testing.
TC is determined by connecting a thermocouple to the device as
shown here:
Thermocouple mount
at tab center
0
TA (°C)
RθJA(°C/W)
VIN is input supply voltage in V,
10
9
8
7
6
5
4
3
2
1
0
VIN (V)
0
1
8
15
20
40
2
3
4
5
6
IO(A)
for this device, RθJC is 3 °C/W.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
5
SI-8008HD
DC-to-DC Step-Down Converter
Component Selection
Diode Di A Schottky-barrier diode must be used for Di. If other
diode types are used, such as fast recovery diodes, the IC may be
destroyed because of the reverse voltage applied by the recovery
voltage or ON voltage.
Choke Coil L1 If the winding resistance of the choke coil is too
high, the efficiency may be reduced below rating. Because the
overcurrent protection start current is approximately 6.5 A, attention must be paid to the heating of the choke coil by magnetic
saturation due to overload or short-circuited load.
Capacitors C1, C2, C3, and C4 Because for SMPS, large
ripple currents flow across C1 and C2, capacitors with high
frequency and low impedance must be used. If the impedance of
C2 is too high, the switching waveform may not be normal at low
temperatures. Do not use either OS or tantalum types of capaci-
tors for C2, because those cause an abnormal oscillation.
The device is stabilized, and for proper operation, C1 and C4
must be located close to the device (see layout diagram, below).
C3 is required only if the soft start function is used. If not using
soft-start, leave the SS terminal open. A pull-up resistor is provided inside the IC.
Resistor Bridge R1 and R2 comprise the resistor bridge for the
output voltage, VO, and are calculated as follows:
(V − V ) (V − 0.8) (Ω) , and R2 = VADJ = 0.8 = 0.8 (k Ω )
R1 = O ADJ = O
−3
−3
1 × 10
IADJ
1 × 10
IADJ
IADJ should always be set to 1 mA. Note that R2 should always be
present to ensure stable operation, even if VO, is set to 0.8 V (that
is, even if there is no R1). VO should be at least VIN + 8%.
Typical Application Diagram
VIN
1
IN
SW
L1
2
SI-8008HD
C1
GND
C4
SS GND
3
5
ADJ
VO
Component
C2
C1
C2
C3
C4
Di
L1
R1
4
IADJ
Di
R2
C3
Soft Start Only
Rating
1500 μF
1000 μF
0.1 μF (For soft start function)
4.7 μF (GRM32ER71H475KA88L)
FMB-G16L (Sanken)
100 μH
GND
Recommended PCB Layout
Recommended Solder Pad Layout
11±0.2
9±0.2
6.8±0.1
9±0.1
3.7±0.05
4±0.1
1±0.05
All external components should be mounted as close as possible
to the SI-8008HD. The ground of all components should be
connected at one point near GND pin (pin 3).
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
1.7±0.1
(mm)
6
SI-8008HD
DC-to-DC Step-Down Converter
9.90 ±0.20
0.80 ±0.10
2.00 ±0.10
3º
(R0.30)
(0.50)
6º
0º
4×P1.70 ±0.25
2.40 ±0.20
2.54 ±0.30
0.88 ±0.10
0.10 ±0.15
3º
(0.75)
4.90 ±0.20
XXXXXXXX
+
(R0.45)
3XR0.30
15.30 ±0.30
XXXXXXXX
XXXXXXXX
Branding
(4.40)
+
3º
9.20 ±0.20
XXXXXXXX
(4.60)
Ø1.5 ±0.20
(0.40)
1.30 –0.05
(0.75)
+0.10
3XR0.30
15º
(8.00)
(6.80)
4.50 ±0.20
2.20 ±0.20
PACKAGE OUTLINE DRAWING
2XR0.30
3º
1
2
3
4
10.00 ±0.02
5
Dimensions do not include mold protrusion
Heastsink side flash: 0.8 mm maximum
Dimensions in millimeters
Branding codes (exact appearance at manufacturer discretion):
1st line:
SK
2nd line, lot:
YMW X
Where: Y is the last digit of the year of manufacture
M is the month (1 to 9, O, N, D)
W is the week of the month (1 to 5)
X is the device subtype suffix number
3rd line, type: 8008HD
RoHS directive compliant
Device pins lead (Pb) free
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
7
SI-8008HD
DC-to-DC Step-Down Converter
2.0 ±0.10
11.5 ±0.05
B
A
0.4 ±0.05
15.7
+0.1
–0.0
24.3 ±0.03
4.0 ±0.10
Ø1.5
1.75 ±0.10
TAPE AND REEL SPECIFICATION
Ø1.5 MIN
A
16.0
B
3.9
4.9
10.6
View A-A
View B-B
Material: conductive polysterene
Material: Conductive polysterene
Camber
< 1mm
mmlength
over 100
length of tape
Camber < 1 mm
over 100
of tape
Pocketmeasured
inner widths
measured
0.3 mm
above floor of pocket
Pocket inner widths
0.3 mm
above floor
of cavity
Pocket position relative to sprocket hole measured to true position of pocket
10 sprocket hole pitch cumulative ±0.2 mm
Pocket center and pocket hole center ±0.3 mm
Surface resistivity < 107 Ω / cm2
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
8
SI-8008HD
DC-to-DC Step-Down Converter
PACKING SPECIFICATION
Inner Carton
800 pieces per reel
2 reels per carton
341
65
344
Outer Carton
3 inner cartons per outer carton
450
230
Dimensions in mm
350
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
9
SI-8008HD
DC-to-DC Step-Down Converter
WARNING — These devices are designed to be operated at lethal voltages and energy levels. Circuit designs
that embody these components must conform with applicable safety requirements. Precautions must be
taken to prevent accidental contact with power-line potentials. Do not connect grounded test equipment.
The use of an isolation transformer is recommended during circuit development and breadboarding.
solder bath must be grounded in other to prevent leak voltages
generated by them from being applied to the products.
•
The products should always be stored and transported in our
shipping containers or conductive containers, or be wrapped in
aluminum foil.
Soldering
•
When manually soldering the products, please be sure to
minimize the working time, within the following limits:
Soldering Iron Temperature
(°C)
Time
(s)
380±10
3
(once only)
•
Reflow soldering can be performed a maximum of twice, using
the following recommended profile:
250°C Maximum
250
230
Temperature (°C)
Cautions for Use
•
Operation of the product in parallel to increase current is not
permitted.
•
Although the product has an internal overtemperature protection
circuit, that is intended only to protect the product from temporary
excess heating due to overloads. Long-term reliability cannot
be guaranteed when the product is operated under continuous
overload conditions.
Because reliability can be affected adversely by improper storage
environments and handling methods, please observe the following
cautions.
Cautions for Storage
•
Ensure that storage conditions comply with the standard
temperature (5°C to 35°C) and the standard relative humidity
(around 40 to 75%); avoid storage locations that experience
extreme changes in temperature or humidity.
•
Avoid locations where dust or harmful gases are present and
avoid direct sunlight.
•
Reinspect for rust on leads and solderability of products that have
been stored for a long time.
Cautions for Testing and Handling
When tests are carried out during inspection testing and other
standard test periods, protect the products from power surges
from the testing device, shorts between adjacent products, and
shorts to the heatsink.
Electrostatic Discharge
•
When handling the products, operator must be grounded.
Grounded wrist straps worn should have at least 1 MΩ of
resistance to ground to prevent shock hazard.
•
Workbenches where the products are handled should be
grounded and be provided with conductive table and floor mats.
•
When using measuring equipment such as a curve tracer, the
equipment should be grounded.
•
When soldering the products, the head of soldering irons or the
180
30 ±10s
150
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
90 ±30s
Time
10
SI-8008HD
DC-to-DC Step-Down Converter
The products described herein are manufactured in Japan by Sanken Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.
Sanken and Allegro reserve the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Therefore, the user is cautioned to verify that the information in this
publication is current before placing any order.
The information included herein is believed to be accurate and reliable. Application and operation examples described in this document are given
for reference only and Sanken assumes no responsibility for any infringement of industrial property right, 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 shall be the users responsibility to
determine.
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 or damages to society due to device failure or malfunction.
Sanken products listed in this 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.). 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 obtain written confirmation of your specifications.
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.
Copyright © 2007 Allegro MicroSystems, Inc.
This datasheet is based on Sanken datasheet SSJ-03118
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
11
DC-to-DC Step-Down Converter
SI-8008HD
January, 2008
<Worldwide Contacts>
Asia Pacific
China
Sanken Electric Hong Kong Co., Ltd.
Suite 1026 Ocean Centre, Canton Road, Tsimshatsui, Kowloon, Hong Kong
Tel: 852-2735-5262
Fax: 852-2735-5494
Sanken Electric (Shanghai) Co., Ltd.
Room3202, Maxdo Centre, Xingyi Road 8, Changning district, Shanghai, China
Tel: 86-21-5208-1177
Fax: 86-21-5208-1757
Taiwan Sanken Electric Co., Ltd.
Room 1801, 18th Floor, 88 Jung Shiau East Road, Sec. 2, Taipei 100, Taiwan R.O.C.
Tel: 886-2-2356-8161
Fax: 886-2-2356-8261
India
Saket Devices Pvt. Ltd.
Office No.13, First Floor, Bandal - Dhankude Plaza, Near PMT Depot, Paud Road, Kothrud, Pune - 411 038, India
Tel: 91-20-5621-2340
91-20-2528-5449
Fax: 91-20-2528-5459
Japan
Sanken Electric Co., Ltd. Overseas Sales Headquaters
Metropolitan Plaza Bldg. 1-11-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-0021, Japan
Tel: 81-3-3986-6164
Fax: 81-3-3986-8637
Korea
Sanken Electric Korea Co., Ltd.
Mirae Asset Life Bldg. 6F, 168 Kongduk-dong, Mapo-ku, Seoul, 121-705, Korea
Tel: 82-2-714-3700
Fax: 82-2-3272-2145
Singapore
Sanken Electric Singapore Pte. Ltd.
150 Beach Road, #14-03 The Gateway West, Singapore 189720
Tel: 65-6291-4755
Fax: 65-6297-1744
Sanken Electric Co., Ltd.
I02-009EB-080130
DC-to-DC Step-Down Converter
SI-8008HD
January, 2008
Europe
United Kingdom
Sanken Power Systems (UK) Limited
Pencoed Technology Park Pencoed, Bridgend CF35 5HY. UK
Tel: 44-1656-869-100
Fax: 44-1656-869-162
North America
United States
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Worcester, Massachusetts 01606, U.S.A.
Tel: 1-508-853-5000
Fax: 1-508-853-3353
Allegro MicroSystems, Inc. (Southern California)
14 Hughes Street, Suite B105, Irvine, CA 92618
Tel: 1-949-460-2003
Fax: 1-949-460-7837
Sanken Electric Co., Ltd.
I02-009EB-080130