BEL SLIN

NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
SLIN-50E1AL
RoHS Compliant
Rev.A
Features

Wide Input Voltage Range

Output Voltage Sequencing

Monotonic Start-up

Over Temperature Protection

Negative Remote On/Off

Output Over Current Protection

True Differential Remote Sense

Tunable Loop (a registered trademark of Lineage Power Systems) to Optimize Dynamic
output voltage response

Parallel Operation With Active Current Sharing

Compliant to RoHS EU Directive 2002/95/EC

UL* 60950 Recognized, CSA† C22.2 No. 60950-1-07 Certified

VDE 0805 (EN60950-1 2
TM
‡
nd
edition) Licensed
Applications


Distributed power architectures
Intermediate bus voltage applications


Telecommunications equipment
Industrial applications
Description
The SLIN-50E1AL power modules are non-isolated dc/dc converters that can deliver up to 50 A of output current.
These modules operate over a wide range of input voltage (VIN = 4.5 Vdc-14 Vdc) and provide a precisely
regulated output voltage from 0.7 Vdc to 2.0 Vdc, programmable via an external resistor. Features include
remote On/Off, adjustable output voltage, over current and over temperature protection, output voltage
TM
sequencing and paralleling. A new feature, the Tunable Loop , allows the user to optimize the dynamic
response of the converter to match the load with reduced amount of output capacitance leading to savings on
cost and PWB area.
Part Selection
Output Voltage
Input Voltage
0.7 Vdc - 2 Vdc
4.5 Vdc - 14 Vdc
Max. Output
Current
50 A
Typical
Efficiency
87%
Model Number
Active Low
SLIN-50E1AL
Notes: Add “G” suffix at the end of the model number to indicate Tray Packaging.
Part Number Explanation
S LIN – 50 E 1A L
1
2
3 4
5
6
1---Surface mount
2---Series code
3---Output current (50A)
4--- Wide input voltage range (4.5-14V)
5--- Wide output voltage range (0.7-2V)
6--- Enable, active low
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
1
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Absolute Maximum Ratings
Min
Typ
Max
Unit
Continuous Input Voltage
-0.3
-
14
V
Sequencing Pin Voltage
-0.3
-
4
V
Operating Ambient Temperature
-40
-
85
C
Storage Temperature
-55
-
125
C
Parameter
Notes
Note: Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These
are absolute stress ratings only, functional operation of the device is not implied at these or any other
conditions in excess of those given in the operations sections of the data sheet. Exposure to absolute
maximum ratings for extended periods can adversely affect the device reliability.
Input Specifications
Min
Typ
Max
Unit
Operating Input Voltage
Parameter
4.5
-
14
V
Input Current (full load)
-
-
26
A
-
73.4
-
mA
-
136
-
mA
Input Stand-by Current
-
1.3
-
mA
VIN = VIN,mon, module disabled
Input Reflected Ripple Current
(pk-pk)
-
-
73
mA
5Hz to 20MHz, 1μH source impedance;
VIN,min to VIN,max, IO= IOmax
I t Inrush Current Transient
-
-
1
As
Input Ripple Rejection (120Hz)
-
50
-
dB
Turn-on Threshold
-
4.26
-
V
Turn-off Threshold
-
4.04
-
V
Hysteresis
-
0.22
-
V
Input Current (no load)
2
Notes
VIN= VIN,min to VIN,max, IO = IO,max
Vo=0.7V, VIN= VIN,mon, IO=0
module enabled
Vo=1.8V, VIN= VIN,mon, IO=0
module enabled
2
CAUTION: This converter is not internally fused. An input line fuse must be used in application.
This power module can be used in a wide variety of applications, ranging from simple standalone operation to
an integrated part of sophisticated power architecture. To preserve maximum flexibility, internal fusing is not
included; however, to achieve maximum safety and system protection, always use an input line fuse. The safety
agencies require a surface mount, fast acting fuse with a maximum rating of 30A. Based on the information
provided in this data sheet on inrush energy and maximum dc input current, the same type of fuse with a lower
rating can be used. Refer to the fuse manufacturer’s data sheet for further information.
Note: Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and
temperature conditions.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
2
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Output Specifications
Parameter
Min
Typ
Max
Unit
Notes
Output Voltage Set Point
-1.0
-
+1.0
%Vo,set
VIN=VIN,nom, IO=IO, nom, Tref=25°C.
Output Voltage
-2.0
-
+2.0
%Vo,set
Over all operating input voltage, resistive load,
and temperature conditions until end of life
Adjustment Range
0.7
-
2.0
V
Remote Sense Range
-
-
0.5
V
Load Regulation
-
-
8
mV
IO=IO, min to IO, max
Line Regulation
-
-
5
mV
VIN=VIN, min to VIN, max
Temperature Regulation
(-40°C to 85°C)
-
-
8
mV
Tref=TA, min to TA, max
Ripple and Noise (pk-pk)
-
-
50
mV
5Hz to 20MHz BW, VIN=VIN, nom and IO=IO, min to
IO, max, Co = 1μF // 10 μF ceramic capacitors
Output Current Range
0
-
50
A
Output DC Current Limit
-
180
-
%Io,max
Output Short-Circuit Current
-
5.5
-
A
Vo≤250mV, Hiccup Mode
Output Capacitance
ESR≥1 mΩ
ESR≥10 mΩ
ESR≥1 mΩ
ESR≥10 mΩ
-
-
1200
10000
20000
20000
uF
uF
uF
uF
Without the Tunable Loop
TM
Without the Tunable Loop
TM
With the Tunable Loop
TM
With the Tunable Loop
-
4.8
-
mS
selected by an external resistor
Hiccup Mode
TM
Case 1: On/Off input is set to Logic Low (Module
Turn-On Delay Time
ON) and then input power is applied (delay from
instant at which VIN =VIN, min until Vo=10% of Vo,set)
Case 2: Input power is applied for at least one
-
4.8
-
mS
Output voltage Rise time
-
3.6
-
mS
Output voltage overshoot
-
-
3
%Vo,set
second and then the On/Off input is set to logic Low
(delay from instant at which Von/Off=0.3V until
Vo=10% of Vo, set)
time for Vo to rise from 10% of Vo, set to 90%
of Vo, set
Io=Io, max,Vin=4.5 to 14Vdc, Ta=25°C
Note: Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and
temperature conditions.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
3
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
General Specifications
Parameter
Min
Typ
Max
Unit
-
81.1
87.0
90.1
-
%
%
%
Switching Frequency
-
260
-
kHz
Over Temperature Protection
-
125
-
C
Sequencing Slew rate capability
-
-
2
V/mS
10
-
-
mS
-
100
200
200
400
mV
mV
-
5
112.5
87.5
-
V
%Vo,set
%Vo,set
Forced Load Share Accuracy
-
10
-
%Io
Number of Units in Parallel
-
-
5
-
Weight
-
14.22
-
g
Efficiency
Vo=0.7V
Vo=1.2V
Vo=1.8V
Sequencing Delay time
Tracking Accuracy
Power-Up: 2V/ms
Power-Down: 1V/ms
PGOOD (Power Good)
Internal pull-up, VPGOOD
Overvoltage threshold for PGOOD
Undervoltage threshold for PGOOD
MTBF
4,755,661
Hours
1.30 x 0.90 x 0.34
33 x 22.9 x 10
-
Notes
Vin= 12Vdc, Ta=25°C
Io=Io, max , Vo= Vo,set
VIN, min to VIN, max; IO, min to IO, max
VSEQ < Vo
Delay from VIN, min to application of
voltage on SEQ pin
VIN, min to VIN, max; IO, min - IO, max
VSEQ < Vo
Calculated MTBF (IO=IO, max,
Ta=40°C) per Telecordia Issue 2,
Method I, Case 3
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
Note: Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and
temperature conditions.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
4
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
95
95
90
90
EFFICIENCY,  (%)
EFFICIENCY,  (%)
Efficiency Data
85
Vin=12V
80
Vin=4.5V
Vin=14V
75
70
Vin=12V
85
Vin=14V
80
Vin =4.5V
75
70
0
10
20
30
40
50
OUTPUT CURRENT, IO (A)
0
10
20
30
40
50
OUTPUT CURRENT, IO (A)
Vo=0.7V, Ta=25°C
Vo=1.2V, Ta=25°C
100
Vin=12V
EFFICIENCY,  (%)
95
90
85
Vin=14V
Vin=4.5V
80
75
70
0
10
20
30
40
50
OUTPUT CURRENT, IO (A)
Vo=1.8V, Ta=25°C
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
5
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
55
55
50
50
OUTPUT CURRENT, Io (A)
OUTPUT CURRENT, Io (A)
Thermal Derating Curves
45
NC
40
0.5m/s
(100LFM)
1.5m/s
(300LFM)
35
1m /s
( 200LFM)
30
2m/s
(400LFM)
25
35
45
55
65
75
85
O
45
NC
40
0.5m/s
(100LFM)
35
1m/s
(200LFM)
30
1.5m/s
(300LFM)
2m/s
(400LFM)
25
35
45
55
65
75
85
O
AMBIENT TEMPERATURE, TA C
AMBIENT TEMPERATURE, TA C
Vo=0.7V, Vin=12V
Vo=1.2V, Vin=12V
55
OUTPUT CURRENT, Io (A)
50
45
40
NC
35
0.5m/s
(100LFM)
30
1.5m/s
1m/s
(300LFM)
(200LFM)
2m/s
(400LFM)
25
35
45
55
65
75
85
AMBIENT TEMPERATURE, TA OC
Vo=1.8V, Vin=12V
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
6
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Bel Power Inc., a subsidiary of Bel Fuse Inc.
OUTPUT VOLTAGE
VO (V) (10mV/div)
OUTPUT VOLTAGE
VO (V) (10mV/div)
Ripple and Noise Waveforms
TIME, t (1s/div)
Vo=1.2V, Ta=25°C , Vin=12V, Io = Io,max
OUTPUT VOLTAGE
VO (V) (10mV/div)
Vo=0.7V, Ta=25°C , Vin=12V, Io = Io,max
TIME, t (1s/div)
TIME, t (1s/div)
Vo=1.8V, Ta=25°C , Vin=12V, Io = Io,max
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
7
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
OUTPUT CURRENT,
IO (A) (10A/div)
OUTPUT VOLTAGE
VO (V) (200mV/div)
OUTPUT CURRENT,
IO (A) (2A/div)
TBD
Bel Power Inc., a subsidiary of Bel Fuse Inc.
OUTPUT VOLTAGE
VO (V) (5mV/div)
February 18, 2011
Transient Response Waveforms
TIME, t (20s /div)
Transient Response to Dynamic Load Change from 50%
to 100%. Vo=1.2V, Ta=25°C, Vin=12V, Cext =5x47uF+
+13x330uFpolymer,CTune=120nF,RTune=180ohms
OUTPUT CURRENT,
IO (A) (10A/div)
OUTPUT VOLTAGE
VO (V) (10mV/div)
Transient Response to Dynamic Load Change from
0% to 50% to 0%. Vo=0.7V, Ta=25°C , Vin=12V
TIME, t (0.5mS /div)
TIME, t (0.5mS /div)
Transient Response to Dynamic Load Change from 50% to
100%. Vo=1.8V, Ta=25°C, Vin=12V, Cext =5x47uF+
+8x330uFpolymer,CTune=47nF,RTune=220ohms
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
8
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
ON/OFF VOLTAGE
VON/OFF (V) (5V/div)
OUTPUT VOLTAGE
Vo (V) (500mV/div)
OUTPUT VOLTAGE
Vo (V) (200mV/div)
ON/OFF VOLTAGE
VON/OFF (V) (5V/div)
Startup Time
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max)
Vo=1.2V, Vin = 12V, Ta=25°C
OUTPUT VOLTAGE
Vo (V) (500mV/div)
ON/OFF VOLTAGE
VON/OFF (V) (5V/div)
Start-up Using On/Off Voltage (Io = Io,max)
Vo=0.7V, Vin = 12V, Ta=25°C
TIME, t (2 ms/div)
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max)
Vo=1.8V, Vin = 12V, Ta=25°C
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
9
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
INPUT VOLTAGE
VIN (V) (5V/div)
Bel Power Inc., a subsidiary of Bel Fuse Inc.
OUTPUT VOLTAGE
Vo(V) (500mV/div)
OUTPUT VOLTAGE
Vo(V) (200mV/div)
INPUT VOLTAGE
VIN (V) (5V/div)
Startup Time (continued)
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=1.2V, Ta=25°C
OUTPUT VOLTAGE
Vo(V) (500mV/div)
INPUT VOLTAGE
VIN (V) (5V/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=0.7V, Ta=25°C
TIME, t (2 ms/div)
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=1.8V, Ta=25°C
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
10
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Test Configurations
Input Reflected Ripple Current Test Setup.
CURRENT PROBE
TO OSCILLOSCOPE
LTES T
VIN(+)
BATTERY
1μH
CIN
CS 1000μF
Electrolytic
2x100μF
Tantalum
E.S.R.<0.1
@ 20 °C 100kHz
COM
NOTE: Measure input reflected ripple current with a simulated
source inductance (L TES T) of 1μH. Capac itor CS offsets
pos sible battery impedance. Measure current as shown
above.
Output Ripple and Noise Test Setup.
COPPER STRIP
RESISTIVE
LOAD
Vo+
0.1uF
10uF
COM
SCOPE USING
BNC SOCKET
GROUND PLANE
NOTE: All voltage measurem ents to be taken at the m odule
terminals, as shown above. If sockets are used then
Kelvin connections are required at the module termi nals
to avoid measurement errors due to socket contact
resistance.
Output Voltage and Efficiency Test Setup.
R distribution
R contac t
Rc ontac t
VI N(+)
VI N
R distribution
R LOAD
VO
R contac t
Rc ontac t
COM
R dis tribution
VO
R dis tribution
CO M
NOTE: All voltag e m easurement s to b e ta ken at th e m odule
termin als, as sh own ab ove. If sockets are use d th en
Kelvin co nnect io ns are req uired a t th e m odule termina ls
to avoid m easu re men t errors due to s ocket co ntact
resist ance.
VO. IO
Efficiency
 =
VIN. IIN
x
100 %
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
11
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Input Filtering
The SLIN-50E1AL module should be connected to a low ac-impedance source. A highly inductive source can
affect the stability of the module. An input capacitor must be placed directly adjacent to the input pin of the
module to minimize input ripple voltage and ensure module stability.
Input Ripple Voltage (mVp-p)
(mVp-p)
To minimize input voltage ripple, ceramic capacitors are recommended at the input of the module. The figure
below shows the input ripple voltage for various output voltages at maximum load current with 2x22µF, 4x22 µF
or 4x47 µF ceramic capacitors and an input of 12V.
250
2x22uF
225
4x22uF
200
4x47uF
175
150
125
100
75
50
1
1.25
1.5
1.75
2
Output Voltage (Vdc)
Output Filtering
The SLIN-50E1AL modules are designed for low output ripple voltage and will meet the maximum output ripple
specification with 0.1 µF ceramic and 10 µF ceramic capacitors at the output of the module. However, additional
output filtering may be required by the system designer for a number of reasons. First, there may be a need to
further reduce the output ripple and noise of the module. Second, the dynamic response characteristics may
need to be customized to a particular load step change.
To reduce the output ripple and improve the dynamic response to a step load change, additional capacitance at
the output can be used. Low ESR polymer and ceramic capacitors are recommended to improve the dynamic
response of the module. For stable operation of the module, limit the capacitance to less than the maximum
output capacitance as specified in the electrical specification table. Optimal performance of the module can be
achieved by using the Tunable Loop feature described later in this data sheet. The figure below shows the output
ripple voltage for various output voltages with external 2x10µF, 2x47 µF, 4x47 µF or 8x47 µF ceramic capacitors
at the input voltage of 12V.
80
2x10uF Ext Cap
2x47uF Ext Cap
Ripple (mVp-p)
70
4x47uF Ext Cap
60
8x47uF Ext Cap
50
40
30
20
10
0
1
1.2
1.4
1.6
1.8
2
Output Voltage(Volts)
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
12
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Safety Considerations
For safety agency approval the power module must be installed in compliance with the spacing and separation
requirements of the end-use safety agency standards, i.e., UL 60950-1 2nd Edition, CSA C22.2 No. 60950-1-07,
DIN EN 60950-1:2006 + A11 (VDE0805 Teil 1 + A11):2009-11; EN 60950-1:2006 + A11:2009-03.
For the converter output to be considered meeting the requirements of safety extra-low voltage (SELV), the input
must meet SELV requirements. The power module has extra-low voltage (ELV) outputs when all inputs are ELV.
The input to these units is to be provided with a fast acting fuse with a maximum rating of 30A in the positive
input lead.
Remote On/Off
Parameter
Signal Low (Unit On)
Signal High (Unit Off)
Active Low
Min
-0.3
Typ
-
Max
0.6
Unit
V
3.0
-
Vin,max
V
Notes
The remote on/off pin open, Unit off.
The SLIN-50E1AL power modules feature an On/Off pin for remote On/Off operation. If not using the On/Off pin,
connect the pin to ground (the module will be ON). The On/Off signal (V on/off) is referenced to ground. The circuit
configuration for remote On/Off operation of the module using the On/Off pin is shown below.
During a Logic High on the On/Off pin (transistor Q1 is OFF), the module remains OFF. The external resistor R1
should be chosen to maintain 3.0V minimum on the On/Off pin to ensure that the module is OFF when transistor
Q1 is in the OFF state. Suitable values for R1 are 4.7K for input voltage of 12V and 3K for 5Vin. During LogicLow when Q1 is turned ON, the module is turned ON.
The On/Off pin can also be used to synchronize the output voltage start-up and shutdown of multiple modules in
parallel. By connecting On/Off pins of multiple modules, the output start-up can be synchronized (please refer to
characterization curves).
Over Current Protection
To provide protection in a fault (output overload) condition, the unit should be equipped with internal
current-limiting circuitry and can endure current limiting continuously. At the point of current-limit inception, the
unit enters hiccup mode. The unit operates normally once the output current is brought back into its specified
range.
VIN+
MODULE
R1
PWM Enable
I ON/OFF
ON/OFF
+
VON/OFF
5.11K
Q1
5.11K
GND
_
Remote On/Off Implementation using ON/OFF
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
13
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Over Temperature Protection
To provide protection in a fault condition, the unit is equipped with a thermal shutdown circuit. The unit will
shutdown if the over temperature threshold of 125°C is exceeded at the thermal reference point Tref. The thermal
shutdown is not intended as a guarantee that the unit will survive temperatures beyond its rating. Once the unit
goes into thermal shutdown it will then wait to cool before attempting to restart.
Input Under-voltage Lockout
At input voltages below the input under voltage lockout limit, the module operation is disabled. The module will
begin to operate at an input voltage above the under voltage lockout turn-on threshold.
Output Voltage Programming
The output voltage of the SLIN-50E1AL can be programmed to any voltage from 0.7Vdc to 2.0Vdc by connecting
a single resistor (shown as Rtrim in the figure below) between Trim+ and Trim- pins of the module. The following
equation will be used to set the output voltage of the module:
 14000 
Rtrim  

Vo  0.7 
Rtrim is the external resistor in Ω
Vo is the desired output voltage
By using a ±0.5% tolerance trim resistor with a TC of ±100ppm, a set point tolerance of ±1.5% can be achieved
as specified in the electrical specification. Table 1 provides Rtrim values required for some common output
voltages.
Table 1
VO, set (V)
0.7
1.0
1.2
1.5
1.8
Rtrim (KΩ)
Open
46.6
28
17.5
12.7
V IN(+)
V O(+)
ON/OFF
TRIM+
Vout
LOAD
R trim
TRIM
GND
Circuit configuration to program output voltage using
an external resistor
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4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Remote Sense
The SLIN-50E1AL power modules have differential Remote Sense to minimize the effects of distribution losses
by regulating the voltage at the Remote Sense pin. The voltage between the SENSE pin and VOUT pin must not
exceed 0.5V. Note that the output voltage of the module cannot exceed the specified maximum value. This
includes the voltage drop between the SENSE and Vout pins. When the Remote Sense feature is not being
used, connect the SENSE pin to the VOUT pin.
Voltage Margining
Output voltage margining can be implemented in the SLIN-50E1AL modules by connecting a resistor, Rmargin-up,
from the Trim pin to the ground pin for margining-up the output voltage and by connecting a resistor, Rmargin-down,
from the Trim pin to output pin for margining-down. The figure below shows the circuit configuration for output
voltage margining.
Vo
Rmargin-down
MODULE
Q2
TRIM+
Rmargin-up
Rtrim
Q1
TRIM–
Circuit Configuration for margining Output voltage
Monotonic Start-up and Shutdown
The SLIN-50E1AL modules have monotonic start-up and shutdown behavior for any combination of rated input
voltage, output current and operating temperature range.
Startup into Pre-biased Output
The SLIN-50E1AL modules can start into a prebiased output as long as the prebias voltage is 0.5V less than the
set output voltage. Note that prebias operation is not supported when output voltage sequencing is used.
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Output Voltage Sequencing
The SLIN-50E1AL modules include a sequencing feature that enables users to implement various types of output
voltage sequencing in their applications. This is accomplished via an additional sequencing pin. When not using
the sequencing feature, leave it unconnected.
When an analog voltage is applied to the SEQ pin, the output voltage tracks this voltage until the output reaches
the set-point voltage. The final value of the SEQ voltage must be set higher than the set-point voltage of the
module. The output voltage follows the voltage on the SEQ pin on a one-to-one basis. By connecting multiple
modules together, multiple modules can track their output voltages to the voltage applied on the SEQ pin.
For proper voltage sequencing, first, input voltage is applied to the module. The On/Off pin of the module is left
unconnected or tied to GND so that the module is ON by default. After applying input voltage to the module, a
minimum 10msec delay is required before applying voltage on the SEQ pin. Alternatively, input voltage can be
applied while the unit is OFF and then the unit can be enabled. In this case the SEQ signal must be applied 10ms
after the unit is enabled. This delay gives the module enough time to complete its internal power-up soft-start
cycle. During the delay time, the SEQ pin may be held to ground.
After the 10msec delay, an analog voltage is applied to the SEQ pin and the output voltage of the module will
track this voltage on a one-to-one volt basis until the output reaches the set-point voltage. To initiate
simultaneous shutdown of the modules, the SEQ pin voltage is lowered in a controlled manner. The output
voltage of the modules tracks the voltages below their set-point voltages on a one-to-one basis. A valid input
voltage must be maintained until the tracking and output voltages reach ground potential.
When using the sequencing feature to control start-up of the module, pre-bias immunity during start-up is
disabled. The pre-bias immunity feature of the module relies on the module being in the diode-mode during startup. When using the sequencing feature, modules goes through an internal set-up time of 10msec, and will be in
synchronous rectification mode when the voltage at the SEQ pin is applied. This will result in the module sinking
current if a pre-bias voltage is present at the output of the module. When pre-bias immunity during start-up is
required, the sequencing feature must be disabled. For additional guidelines on using the sequencing feature
please contact the Bel Power technical representatives for additional information.
Power Good
The SLIN-50E1AL modules provide a Power Good (PGOOD) signal to indicate that the output voltage is within
the regulation limits of the power module. The PGOOD signal will be de-asserted to a low state if any condition
such as over-temperature, over-current or loss of regulation occurs that would result in the output voltage going
±12.5% outside the set point value. The PGOOD terminal is internally pulled-up and provides a voltage of ~5V,
when asserted, thus eliminating the need for an external source and pull-up resistor.
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Active Load Sharing
For additional power requirements, the SLIN-50E1AL power module is also available with a parallel option. Up to
five modules can be configured, in parallel, with active load sharing.
Good layout techniques should be observed when using multiple units in parallel. To implement forced load
sharing, the following connections should be made:
 The share pins of all units in parallel must be connected together. The path of these connections should be
as direct as possible.

All remote-sense pins should be connected to the power bus at the same point, i.e., connect all the SENSE(+)
pins to the (+) side of the bus. Close proximity and directness are necessary for good noise immunity.
Some special considerations apply for design of converters in parallel operation:
 When sizing the number of modules required for parallel operation, take note of the fact that current sharing
has some tolerance. In addition, under transient conditions such as a dynamic load change and during
startup, all converter output currents will not be equal. To allow for such variation and avoid the likelihood of
a converter shutting off due to a current overload, the total capacity of the paralleled system should be no
more than 75% of the sum of the individual converters. As an example, for a system of four SLIN-50E1AL
converters in parallel, the total current drawn should be less that 75% of (4 x 50A), i.e. less than 150A.

All modules should be turned on and off together. This is so that all modules come up at the same time
avoiding the problem of one converter sourcing current into the other leading to an over current trip condition.
To ensure that all modules come up simultaneously, the on/off pins of all paralleled converters should be tied
together and the converters enabled and disabled using the on/off pin.

The share bus is not designed for redundant operation and the system will be non-functional upon failure of
one of the unit when multiple units are in parallel. In particular, if one of the converters shuts down during
operation, the other converters may also shut down due to their outputs hitting current limit. In such a
situation, unless a coordinated restart is ensured, the system may never properly restart since different
converters will try to restart at different times causing an overload condition and subsequent shutdown. This
situation can be avoided by having an external output voltage monitor circuit that detects a shutdown
condition and forces all converters to shut down and restart together.
Tunable LoopTM
The SLIN-50E1AL modules have a new feature that optimizes transient response of the module called Tunable
TM
Loop .
External capacitors are usually added to the output of the module for two reasons: to reduce output ripple and
noise and to reduce output voltage deviations from the steady-state value in the presence of dynamic load
current changes. Adding external capacitance however affects the voltage control loop of the module, typically
causing the loop to slow down with sluggish response. Larger values of external capacitance could also cause
the module to become unstable.
TM
The Tunable Loop allows the user to externally adjust the voltage control loop to match the filter network
connected to the output of the module. The Tunable LoopTM is implemented by connecting a series R-C between
the SENSE and TRIM pins of the module. This R-C allows the user to externally adjust the voltage loop feedback
compensation of the module.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Tunable LoopTM (continued)
VOUT
SENSE+
RTUNE
MODULE
CO1
CTUNE
TRIM+
RTrim
TRIMGND SENSE-
Circuit diagram showing connection of RTUNE and CTUNE to tune the control loop of the module
Recommended values of RTUNE and CTUNE for different output capacitor combinations are given in Tables 2 and 3.
Table 2 shows the recommended values of RTUNE and CTUNE for different values of ceramic output capacitors up
to 1000uF that might be needed for an application to meet output ripple and noise requirements. Selecting R TUNE
and CTUNE according to Table 2 will ensure stable operation of the module.
In applications with tight output voltage limits in the presence of dynamic current loading, additional output
capacitance will be required. Table 3 lists recommended values of RTUNE and CTUNE in order to meet 2% output
voltage deviation limits for some common output voltages in the presence of a 25A to 50A step change (50% of
full load), with an input voltage of 12V.
Table 2.General recommended values of RTUNE and CTUNE for Vin=12V and various external ceramic capacitor
combinations.
CO
RTUNE
CTUNE
1 x 47uF 2x47uF
330
330
330pF
560pF
4x47uF
330
1200pF
6x47uF 10 x 47uF 20 x 47uF
330
270
270
1800pF
2200pF
5600pF
Table 3.Recommended values of RTUNE and CTUNE to obtain transient deviation of 2% of Vout for a 25A step
load with Vin=12V.
VO
1.8V
5x47uF +
8x330uF
polymer
1.2V
5x47uF +
13x330uF
polymer
0.7V
5x47uF +
22x330uF
polymer
RTUNE
220
180
100
CTUNE
V
47nF
35mV
120nF
23mV
330nF
14mV
CO
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Thermal Considerations
Power modules operate in a variety of thermal environments; however, sufficient cooling should always be
provided to help ensure reliable operation.
Considerations include ambient temperature, airflow, module power dissipation, and the need for increased
reliability. A reduction in the operating temperature of the module will result in an increase in reliability. The
thermal data presented here is based on physical measurements taken in a wind tunnel. The test set-up is
shown below.
25.4_
(1.0)
Wind Tunnel
PWBs
Power Module
76.2_
(3.0)
x
12.7_
(0.50)
Probe Location
for measuring
airflow and
ambient
temperature
Air
flow
Thermal Test Setup
The thermal reference points, Tref used in the specifications is shown below. For reliable operation the
o
temperatures at this point should not exceed 125 C. The output power of the module should not exceed the rated
power of the module (Vo,set x Io,max).
Preferred airflow direction and location of hot-spot of the module (Tref).
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Example Application Circuit
Requirements:
Vin:
Vout:
Iout:
Vout:
Vin, ripple
12V
1.8V
37.5A max., worst case load transient is from 25A to 37.5A
1.5% of Vout (27mV) for worst case load transient
1.5% of Vin (180mV, p-p)
Vin+
Vout+
VOUT
VIN
PGOOD
SENSE+
RTUNE
SEQ
+
CI2
CI1
MODULE
ON/OFF
CO1
+
CO2
CTUNE
TRIM+
RTrim
TRIM-
GND
CI1
CI2
CO1
CO2
CTune
RTune
RTrim
SESENSE-
4x22F/16V ceramic capacitor (e.g. Murata GRM32ER61C226KE20)
200F/16V bulk electrolytic
5x47F/6.3V ceramic capacitor (e.g. Murata GRM31CR60J476ME19)
8x 330F/6.3V Polymer (e.g. Sanyo Poscap)
47nF ceramic capacitor (can be 1206, 0805 or 0603 size)
220 ohms SMT resistor (can be 1206, 0805 or 0603 size)
12.7k SMT resistor (can be 1206, 0805 or 0603 size, recommended tolerance of 0.1%)
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Mechanical Outline
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Mechanical Outline (continued)
Recommended Pad Layout
Pin Define
pin#
function
1
VIN
2
GND
3
VOUT
4
VOUT
5
GND
6
VIN
7
SEQ
8
PGOOD
9
ON/OFF
10
VS-
11
VS+
12
+TRIM
13
–TRIM
14
SHARE
Dimensions are in millimeters and (inches).
Tolerances: x.x mm  0.5 mm (x.xx in.  0.02 in.) [Unless otherwise indicated]
x.xx mm  0.25 mm (x.xxx in  0.010 in.)
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Packaging Details
The SLIN-50E1AL modules are supplied in tape & reel as standard.
All Dimensions are in millimeters and (in inches).
Reel Dimensions:
Outside Dimensions:
Inside Dimensions:
Tape Width:
330.2 mm (13.00’’)
177.8 mm (7.00”)
56.00 mm (2.20”)
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Surface Mount Information
Pick and Place
The SLIN-50E1AL modules use an open frame construction and are designed for a fully automated assembly
process. The modules are fitted with a label designed to provide a large surface area for pick and place
operations. The label meets all the requirements for surface mount processing, as well as safety standards, and
is able to withstand reflow temperatures of up to 300oC. The label also carries product information such as part
number and serial number.
Pick and Place Location.
Nozzle Recommendations
The module weight has been kept to a minimum by using open frame construction. Even so, these modules
have a relatively large mass when compared to conventional SMT components. Variables such as nozzle size,
tip style, vacuum pressure and pick & placement speed should be considered to optimize this process. The
minimum recommended inside nozzle diameter for reliable operation is 3mm. The maximum nozzle outer
diameter, which will safely fit within the allowable component spacing, is 5 mm max.
Bottom Side Assembly
This module is not recommended for assembly on the bottom side of a customer board. If such an assembly is
attempted, components may fall off the module during the second reflow process. If assembly on the bottom side
is planned, please contact Bel Power for special manufacturing process instructions.
Lead Free Soldering
The SLIN-50E1AL modules are lead-free (Pb-free) and RoHS compliant and are both forward and backward
compatible in a Pb-free and a SnPb soldering process. Failure to observe the instructions may result in the
failure of or cause damage to the modules and can adversely affect long-term reliability.
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Surface Mount Information (Continued)
Pb-free Reflow Profile
Power Systems will comply with J-STD-020 Rev. C (Moisture/Reflow Sensitivity Classification for Nonhermetic
Solid State Surface Mount Devices) for both Pb-free solder profiles and MSL classification procedures. This
standard provides a recommended forced-air-convection reflow profile based on the volume and thickness of the
package. The suggested Pb-free solder paste is Sn/Ag/Cu (SAC). The recommended linear reflow profile using
Sn/Ag/Cu solder is shown below.
Per J-STD-020 Rev. C
300
Peak Temp 260°C
Reflow Temp (°C)
250
Cooling Zone
4°C/Second
200
* Min. Time Above 235°C
15 Seconds
150
100
*Time Above 217°C
60 Seconds
Heating Zone
1°C/Second
50
0
Reflow Time (Seconds)
Note: Soldering outside of the recommended profile requires testing to verify results and performance.
Tin Lead Soldering
The SLIN-50E1AL power modules are lead free modules and can be soldered either in a lead-free solder
process or in a conventional Tin/Lead (Sn/Pb) process. It is recommended that the customer review data sheets
in order to customize the solder reflow profile for each application board assembly. The following instructions
must be observed when soldering these units. Failure to observe these instructions may result in the failure of or
cause damage to the modules, and can adversely affect long-term reliability.
o
In a conventional Tin/Lead (Sn/Pb) solder process peak reflow temperatures are limited to less than 235 C.
o
Typically, the eutectic solder melts at 183 C, wets the land, and subsequently wicks the device connection.
Sufficient time must be allowed to fuse the plating on the connection to ensure a reliable solder joint. There are
several types of SMT reflow technologies currently used in the industry. These surface mount power modules
can be reliably soldered using natural forced convection, IR (radiant infrared), or a combination of convection/IR.
For reliable soldering the solder reflow profile should be established by accurately measuring the modules CP
connector temperatures.
300
240
P eak Temp 235oC
235
200
Co o ling
zo ne
1-4oCs -1
Heat zo ne
max 4oCs -1
150
100
50
So ak zo ne
30-240s
Tlim above
205oC
P reheat zo ne
max 4oCs -1
MAX TEMP SOLDER (C)
REFLOW TEMP (C)
250
230
225
220
215
210
205
200
0
0
REFLOW TIME (S)
Reflow Profile for Tin/Lead (Sn/Pb) process
10
20
30
40
50
60
o
Time Limit Curve Above 205 C Reflow for Tin
Lead (Sn/Pb) process
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
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NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
February 18, 2011
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Surface Mount Information (Continued)
MSL Rating
The SLIN-50E1AL modules have a MSL rating of 2.
Storage and Handling
The recommended storage environment and handling procedures for moisture-sensitive surface mount packages
is detailed in J-STD-033 Rev. A (Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface
Mount Devices). Moisture barrier bags (MBB) with desiccant are required for MSL ratings of 2 or greater. These
sealed packages should not be broken until time of use. Once the original package is broken, the floor life of the
product at conditions of <= 30°C and 60% relative humidity varies according to the MSL rating (see J-STD-033A).
The shelf life for dry packed SMT packages will be a minimum of 12 months from the bag seal date, when stored
at the following conditions: < 40° C, < 90% relative humidity.
Post Solder Cleaning and Drying Considerations
Post solder cleaning is usually the final circuit-board assembly process prior to electrical board testing. The result
of inadequate cleaning and drying can affect both the reliability of a power module and the testability of the
finished circuit-board assembly.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
26
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.7 Vdc – 2 Vdc /50 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
February 18, 2011
Revision History
Date
Revision
2011-2-18
A
Changes Detail
Approval
First release
T. Bubriski
RoHS Compliance
Complies with the European Directive 2002/95/EC, calling for the elimination of lead and
other hazardous substances from electronic products.
2011 Bel Fuse Inc. Specifications subject to change without notice. 021811
27
CORPORATE
FAR EAST
EUROPE
Bel Fuse Inc.
206 Van Vorst Street
Jersey City, NJ 07302
Tel 201-432-0463
Fax 201-432-9542
www.belfuse.com
Bel Fuse Ltd.
8F/ 8 Luk Hop Street
San Po Kong
Kowloon, Hong Kong
Tel 852-2328-5515
Fax 852-2352-3706
www.belfuse.com
Bel Fuse Europe Ltd.
Preston Technology Management Centre
Marsh Lane, Suite G7, Preston
Lancashire, PR1 8UD, U.K.
Tel 44-1772-556601
Fax 44-1772-888366
www.belfuse.com