Bel Power Inc., a subsidiary of Bel Fuse Inc. NON

NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
SLDN-12D1Ax
RoHS Compliant
Rev.B
Features

Non-Isolated

Wide Input voltage range (3Vdc-14.4Vdc)

Power Good signal

Cost efficient open frame design

Remote On/Off

Ability to sink and source current

Overtemperature protection

DOSA based

Compliant to IPC-9592 (September 2008), Category 2, Class II

Compliant to RoHS EU Directive 2002/95/EC



Compatible in a Pb-free or SnPb reflow environment
Output voltage programmable from 0.6Vdc to 5.5Vdc via external resistor.
Digitally adjustable down to 0.45Vdc
TM
Digital interface through the PMBus protocol

Tunable Loop

Flexible output voltage sequencing EZ-SEQUENCE

Fixed switching frequency with capability of external synchronization

Output overcurrent protection (non-latching)

Wide operating temperature range [-40°C to 85°C]

UL60950-1 Recognized (UL/cUL) (Pending)

ISO 9001 and ISO 14001 certified manufacturing facilities
TM
to op timize dynamic output voltage response
Applications

Distributed power architectures

Servers and storage applications

Intermediate bus voltage applications

Networking equipment

Telecommunications equipment

Industrial equipment
Description
The SLDN-12D1Ax power modules are non-isolated dc-dc converters that can deliver up to 12A of output
current. These modules operate over a wide range of input voltage (VIN = 3Vdc-14.4Vdc) and provide a precisely
regulated output voltage from 0.45Vdc to 5.5Vdc, programmable via an external resistor and PMBus control.
Features include a digital interface using the PMBus protocol, remote On/Off, adjustable output voltage, over
current and overtemperature protection. The PMBus interface supports a range of commands to both control and
TM
monitor the module. The module also includes the Tunable Loop feature that 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
0.45 - 5.5 Vdc
3 - 14.4 Vdc
Max. Output
Current
12 A
Max. Output
Power
60W
Typical
Efficiency
95.4%
Model Number
Active High
SLDN-12D1A0
Model Number
Active Low
SLDN-12D1AL
Notes: Add “G” suffix at the end of the model number to indicate Tray Packaging.
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Part Number Explanation
S LDN – 12 D 1A 0
1
2
3
4
5
6
1---Surface mount
2---Series code
3---Output current (12A)
4--- Wide input voltage range (3-14.4V)
5--- With sequencing
6---Enable, active high, change “0” to “L”
means active low
Absolute Maximum Ratings
Parameter
Min
Typ
Max
Unit
Continuous Input Voltage
-0.3
-
15
V
Voltage on SEQ ,SYNC,VS+ terminal
-
-
7
V
Voltage on CLK,DATA,SMBALERT
terminal
-
-
3.6
V
Operating Ambient Temperature
-40
TA
85
C
Storage Temperature
-55
Tstg
125
C
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
Parameter
Operating Input Voltage
Min
3
Typ
-
Max
14.4
Unit
V
Input Current (full load)
-
-
9
A
VIN=3V to 14.4V
-
52
-
mA
VO,set = 0.6 Vdc
-
85
-
mA
VO,set = 5 Vdc
Input Stand-by Current
-
6.5
-
mA
VIN = 12V, module disabled
Input Reflected Ripple Current
(pk-pk)
-
400
-
mA
5Hz to 20MHz, 1μH source impedance; VIN
=0 to 14V, IO= IOmax
I t Inrush Current Transient
-
-
1
As
Input Ripple Rejection (120Hz)
-
-55
-
dB
Input Current (no load)
2
Notes
VIN = 12Vdc, 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 fast-acting fuse with a maximum rating of 15A. 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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Output Specifications
Parameter
Min
Typ
Max
Unit
Output Voltage Set Point
-1.0
-
+1.0
%Vo,set
Output Voltage
-3.0
-
+3.0
%Vo,set
Output Voltage Range
-25
0
+25
%Vo,set
-
0.4
-
%Vo,set
0.6
-
5.5
V
-
-
0.5
V
VO ≥ 2.5V
VO < 2.5V
-
-
10
10
mV
mV
VO ≥ 2.5V
VO < 2.5V
-
-
0.4
5
%Vo,set
mV
VIN=VIN, min to VIN, max
Temperature Regulation
(Tref=TA, min to TA, max)
-
-
0.4
%Vo,set
Tref=TA, min to TA, max
Ripple and Noise (pk-pk)
-
50
100
mV
Ripple and Noise (rms)
-
20
38
mV
Output Short-Circuit Current
-
0.92
-
A
Vo≤250mV, Hiccup Mode
Output Capacitance2
ESR≥ 1 mΩ
ESR≥0.15 mΩ
ESR≥ 10 mΩ
22
22
22
-
47
1000
5000
uF
uF
uF
Without the Tunable Loop
TM
With the Tunable Loop
TM
With the Tunable Loop
Output Current
0
-
12
A
In either sink or source mode
Output Current Limit
Inception
-
130
-
% Io,max
-
1.1
-
msec
Case 1: On/Off input is enabled and then input
power is applied (delay from instant at which
VIN = VIN, min until VO = 10% of Vo, set )
Output Voltage Adjustment
Step Size
Adjustment Range
Remote Sense Range
Notes
with 0.1% tolerance for external resistor used to
set output voltage
Over all operating input voltage, resistive load,
and temperature conditions until end of life
Some output voltages may not be possible
depending on the input voltage – see Feature
Descriptions Section
Load Regulation
IO=IO, min to IO, max
Line Regulation
Turn-On Delay and Rise
Times
(VIN=VIN, nom, IO=IO, max , VO to
within ±1% of steady state)
Output voltage Rise time
5Hz to 20MHz BW, VIN=VIN, nom and IO=IO, min to
IO, max Co = 0.1μF // 22 μF ceramic capacitors)
TM
Current limit does not operate in sink mode
-
700
-
μsec
Case 2: Input power is applied for at least one
second and then the On/Off input is enabled
(delay from instant at which Von/Off is enabled
until Vo = 10% of Vo, set)
-
3.1
-
msec
time for Vo to rise from 10% of VO, set to 90%
of Vo, set
Notes: 1. Some output voltages may not be possible depending on the input voltage.
TM
2. External capacitors may require using the new Tunable Loop feature to ensure that the module is
TM
stable as well as getting the best transient response (See the Tunable Loop section for details).
3. 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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
General Specifications
Parameter
Min
Typ
Max
Unit
-
76.4
86.0
89.9
92.2
93.6
95.4
-
%
%
%
%
%
%
Switching Frequency
-
600
-
kHz
Over Temperature Protection
-
150
-
C
-
VSEQ -Vo
VSEQ -Vo
100
100
mV
mV
Notes
Efficiency
Vo=0.6V
Vo=1.2V
Vo=1.8V
Vo=2.5V
Vo=3.3V
Vo=5.0V
Tracking Accuracy
Power-Up: 2V/ms
Power-Down: 2V/ms
PGOOD (Power Good)
Overvoltage threshold for PGOOD ON
Overvoltage threshold for PGOOD OFF
Undervoltage threshold for PGOOD ON
Undervoltage threshold for PGOOD OFF
Pulldown resistance of PGOOD pin
Sink current capability into PGOOD pin
-
Weight
-
MTBF
108
110
92
90
-
50
5
2.23
-
%VO, set
%VO, set
%VO, set
%VO, set
Ω
mA
Vin= 12Vdc, TA=25°C
Io=Io, max , Vo= Vo,set
Vin, min to Vin, max; Io, min to Io, max,
VSEQ < Vo
Signal Interface Open Drain,
Vsupply  5Vdc
g
21,774,843
hours
0.48 x 0.48 x 0.335
12.2 x 12.2 x 8.5
-
Calculated MTBF (IO=0.8IO, max,
TA=40°C) Telecordia Issue 2
Method 1 Case 3
Dimensions
Inches (L × W × H)
Millimeters (L × W × H)
Frequency Synchronization
Synchronization Frequency Range
510
-
720
KHz
High-Level Input Voltage
2.0
-
-
V
Low-Level Input Voltage
-
-
0.4
V
Input Current, SYNC
-
-
100
mA
Minimum Pulse Width, SYNC
100
-
-
nS
Minimum Setup/Hold Time, SYNC
100
-
-
nS
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Efficiency Data
85
95
90
85
Vin=3V
75
EFFICIENCY,  (%)
EFFICIENCY,  (%)
80
70
Vin=12V
Vin=14V
65
60
55
50
Vin=3V
80
75
Vin=14V
Vin=12V
70
65
60
55
50
0
2
4
6
8
10
12
0
2
OUTPUT CURRENT, IO (A)
4
6
8
10
12
10
12
OUTPUT CURRENT, IO (A)
Vo=0.6V
Vo=1.2V
95
100
95
90
EFFICIENCY,  (%)
EFFICIENCY,  (%))
Vin=3.5V
85
Vin=12V
Vin=14V
80
75
70
90
Vin=4.5V
85
Vin=14V
80
75
70
0
2
4
6
8
10
12
0
2
OUTPUT CURRENT, IO (A)
100
95
95
Vin=14V
EFFICIENCY,  (%)
90
85
6
8
Vo=2.5V
100
Vin=4.5V
4
OUTPUT CURRENT, IO (A)
Vo=1.8V
EFFICIENCY,  (%))
Vin=12V
Vin=12V
80
75
70
90
Vin=7V
Vin=14V
Vin=12V
85
80
75
70
0
2
4
6
8
OUTPUT CURRENT, IO (A)
Vo=3.3V
10
12
0
2
4
6
8
10
12
OUTPUT CURRENT, IO (A)
Vo=5.0V
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Thermal Derating Curves
12
10
OUTPUT CURRENT, Io (A)
OUTPUT CURRENT, Io (A)
12
NC
8
0.5m/s
(100LFM)
Standard Part
(85°C)
6
1.5m/s
(300LFM)
Ruggedized (D)
Part (105°C)
4
1m/s
(200LFM)
2
2m/s
2m/s
(400LFM)
(400LFM)
0
55
65
75
85
95
10
NC
0.5m/s
(100LFM)
8
6
Standard
Part (85 C)
4
2m/s
(400LFM)
0
105
55
65
75
85
95
105
AMBIENT TEMPERATURE, TA OC
Vo=0.6V
Vo=1.2V
12
10
OUTPUT CURRENT, Io (A)
12
OUTPUT CURRENT, Io (A)
1.5m/s
(300LFM)
Ruggedized (D)
Part (105°C)
2
AMBIENT TEMPERATURE, TA OC
NC
0.5m/s
(100LFM)
8
6
Standard Part
(85°C)
4
1m/s
(200LFM)
Ruggedized (D)
Part (105°C)
2
1.5m/s
(300LFM)
2m/s
(400LFM)
0
55
65
75
85
95
10
NC
0.5m/s
(100LFM)
8
6
1m/s
(200LFM)
Standard
Part (85°C)
4
1.5m/s
(300LFM)
2m/s
(400LFM
Ruggedized (D)
Part (105°C)
2
0
55
105
O
65
75
85
95
105
O
AMBIENT TEMPERATURE, TA C
AMBIENT TEMPERATURE, TA C
Vo=1.8V
Vo=2.5V
12
10
OUTPUT CURRENT, Io (A)
12
OUTPUT CURRENT, Io (A)
1m/s
(200LFM)
NC
0.5m/s
(100LFM)
8
1m/s
(200LFM)
6
Standard
Part (85°C)
4
1.5m/s
(300LFM)
Ruggedized (D)
Part (105°C)
2
2m/s
(400LFM)
0
55
65
75
85
95
O
AMBIENT TEMPERATURE, TA C
Vo=3.3V
105
10
NC
0.5m/s
(100LFM)
8
1m/s
(200LFM)
6
1.5m/s
(300LFM)
Standard
Part (85°C)
4
Ruggedized (D)
Part (105°C)
2
2m/s
(400LFM)
0
45
55
65
75
85
95
105
O
AMBIENT TEMPERATURE, TA C
Vo=5.0V
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Oct. 11,2012
Bel Power Inc., a subsidiary of Bel Fuse Inc.
OUTPUT VOLTAGE
VO (V) (20mV/div)
OUTPUT VOLTAGE
VO (V) (20mV/div)
Output ripple and Noise Waveforms
TIME, t (1s/div)
TIME, t (1s/div)
Vo=1.2V, Io = Io,max
OUTPUT VOLTAGE
VO (V) (20mV/div)
OUTPUT VOLTAGE
VO (V) (20mV/div)
Vo=0.6V, Io = Io,max
TIME, t (1s/div)
TIME, t (1s/div)
Vo=2.5V, Io = Io,max
OUTPUT VOLTAGE
VO (V) (20mV/div)
OUTPUT VOLTAGE
VO (V) (20mV/div)
Vo=1.8V, Io = Io,max
TIME, t (1s/div)
Vo=3.3V, Io = Io,max
TIME, t (1s/div)
Vo=5.0V, 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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to100%. Vo=1.2V
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to100%. Vo=2.5V
OUTPUT VOLTAGE
VO (V) (50mV/div)
OUTPUT VOLTAGE
VO (V) (50mV/div)
OUTPUT CURRENT,
IO (A) (10Adiv)
OUTPUT VOLTAGE
VO (V) (20mV/div)
OUTPUT VOLTAGE
VO (V) (20mV/div)
OUTPUT CURRENT,
IO (A) (10Adiv)
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to 100%. Vo=1.8V
OUTPUT CURRENT,
IO (A) (10Adiv)
OUTPUT CURRENT,
IO (A) (10Adiv)
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to 100%. Vo=0.6V
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to 100%. Vo=3.3V
OUTPUT CURRENT,
IO (A) (10Adiv)
OUTPUT CURRENT,
IO (A) (10Adiv)
OUTPUT VOLTAGE
VO (V) 5 mV/div)
OUTPUT VOLTAGE
VO (V) (10 mV/div)
Transient Response Waveforms
TIME, t (100s /div)
Transient Response to Dynamic Load Change from
50% to 100%. Vo=5.0V
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
TIME, t (2 ms/div)
ON/OFF VOLTAGE OUTPUT VOLTAGE
VON/OFF (V) (5V/div)
VO (V) (1V/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=1.8V
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=3.3V
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=1.2V
ON/OFF VOLTAGE OUTPUT VOLTAGE
VON/OFF (V) (5V/div)
VO (V) (500mV/div)
ON/OFF VOLTAGE OUTPUT VOLTAGE
VON/OFF (V) (5V/div)
VO (V) (500mV/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=0.6V
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=2.5V
ON/OFF VOLTAGE OUTPUT VOLTAGE
VON/OFF (V) (5V/div)
VO (V) (1V/div)
ON/OFF VOLTAGE OUTPUT VOLTAGE
VON/OFF (V) (200V/div)
VO (V) (5V/div)
TIME, t (2 ms/div)
ON/OFF VOLTAGE
OUTPUT VOLTAGE
VON/OFF (V) (5V/div)
VO (V) (500mV/div)
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Startup Time
TIME, t (2 ms/div)
Start-up Using On/Off Voltage (Io = Io,max), Vo=5.0V
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Oct. 11,2012
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=3.3V
INPUT VOLTAGE
VIN (V) (5V/div)
OUTPUT VOLTAGE
VO (V) (500mV/div)
OUTPUT VOLTAGE
VO (V) (500mV/div)
INPUT VOLTAGE
VIN (V) (5V/div)
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=1.8V
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=1.2V
INPUT VOLTAGE
OUTPUT VOLTAGE
VIN (V) (5V/div)
VO (V) (1V/div)
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=0.60V
INPUT VOLTAGE
OUTPUT VOLTAGE
VIN (V) (5V/div)
VO (V) (1V/div)
Bel Power Inc., a subsidiary of Bel Fuse Inc.
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=2.5V
INPUT VOLTAGE
OUTPUT VOLTAGE
VIN (V) (5V/div)
VO (V) (2V/div)
INPUT VOLTAGE
VIN (V) (5V/div)
OUTPUT VOLTAGE
VO (V) (200mV/div)
Startup Time (continued)
TIME, t (2 ms/div)
Start-up Using Input Voltage (VIN = 12V, Io = Io,max ),
Vo=5.0V
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
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Input Filtering
The SLDN-12D1Ax module should be connected to a low ac-impedance source. A highly inductive source can
affect the stability of the module. An input capacitance must be placed directly adjacent to the input pin of the
module, to minimize input ripple voltage and ensure module stability.
To minimize input voltage ripple, ceramic capacitors are recommended at the input of the module. Figure 37
shows the input ripple voltage for various output voltages at 12A of load current with 2x22 µF or 3x22 µF ceramic
capacitors and an input of 12V.
Figure 37
250
2x22uF
Ripple (mVp-p)
3x22uF
200
150
100
50
0.5
1.5
2.5
3.5
4.5
Output Voltage(Volts)
Note: Input ripple voltage for various output voltages with 2x22 µF or 3x22 µF ceramic capacitors at the input
(12A load). Input voltage is 12V.
Output Filtering
These modules are designed for low output ripple voltage and will meet the maximum output ripple specification
with 0.1 µF ceramic and 22 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. Figure 38 provides output ripple information for different external capacitance values at
various Vo and a full load current of 12A. 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
TM
module can be achieved by using the Tunable Loop feature described later in this data sheet.
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Output Filtering (continued)
Figure 38
60
1x22uF Ext Cap
1x47uF Ext Cap
Ripple (mVp-p)
50
2x47uF Ext Cap
4x47uF Ext Cap
40
30
20
10
0
0.5
1.5
2.5
3.5
4.5
Output Voltage(Volts)
Note: Output ripple voltage for various output voltages with external 1x10 µF, 1x47 µF, 2x47 µF or 4x47 µF
ceramic capacitors at the output (12A load). Input voltage is 12V.
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, 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 slow-blow fuse with a maximum rating of 15 A in the positive
input lead.
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Analog Feature Descriptions
Remote On/Off
Parameter
Signal Low (Unit On)
Signal High (Unit Off)
Signal Low (Unit Off)
Signal High (Unit On)
Active Low
Active High
Min
- 0.2
Typ
-
Max
0.6
Unit
V
2.0
-
Vin,max
V
- 0.2
-
0.6
V
2.0
-
Vin,max
V
Notes
The remote on/off pin open, Unit on.
The remote on/off pin open, Unit on.
The SLDN-12D1Ax module can be turned ON and OFF either by using the ON/OFF pin (Analog interface) or
through the PMBus interface (Digital). The module can be configured in a number of ways through the PMBus
interface to react to the two ON/OFF inputs:
 Module ON/OFF can be controlled only through the analog interface (digital interface ON/OFF
commands are ignored)
 Module ON/OFF can be controlled only through the PMBus interface (analog interface is ignored)
 Module ON/OFF can be controlled by either the analog or digital interface
The default state of the module (as shipped from the factory) is to be controlled by the analog interface only. If
the digital interface is to be enabled, or the module is to be controlled only through the digital interface, this
change must be made through the PMBus. These changes can be made and written to non-volatile memory on
the module so that it is remembered for subsequent use.
Analog On/Off
The SLDN-12D1Ax power modules feature an On/Off pin for remote On/Off operation. Two On/Off logic options
are available. In the Positive Logic On/Off option, (device code suffix “0” – see Ordering Information), the module
turns ON during a logic High on the On/Off pin and turns OFF during a logic Low. With the Negative Logic
On/Off option, (device code suffix “L” – see Ordering Information), the module turns OFF during logic High and
ON during logic Low. The On/Off signal should be always referenced to ground. For either On/Off logic option,
leaving the On/Off pin disconnected will turn the module ON when input voltage is present.
For positive logic modules, the circuit configuration for using the On/Off pin is shown in Figure 39. When the
external transistor Q2 is in the OFF state, the internal transistor Q1 is turned ON, and the internal PWM #Enable
signal is pulled low causing the module to be ON. When transistor Q2 is turned ON, the On/Off pin is pulled low
and the module is OFF. A suggested value for Rpullup is 20k.
For negative logic On/Off modules, the circuit configuration is shown in Fig. 40. The On/Off pin should be pulled
high with an external pull-up resistor (suggested value for the 3V to 14V input range is 20Kohms). When
transistor Q2 is in the OFF state, the On/Off pin is pulled high, transistor Q1 is turned ON and the module is OFF.
To turn the module ON, Q2 is turned ON pulling the On/Off pin low, turning transistor Q1 OFF resulting in the
PWM Enable pin going high.
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Digital On/Off
Please see the Digital Feature Descriptions section.
Figure 39
DLYNX MODULE
+3.3V
+VIN
Rpullup
I
10K
ENABLE
22K
ON/OFF
Q1
+
Q2
V
ON/OFF
_
22 K
GND
Circuit configuration for using positive On/Off logic
Figure 40
DLYNX MODULE
+3.3V
+VI N
Rpu llup
I
10 K
ENABLE
ON/OFF
22K
Q1
+
Q2
V
ON/OFF
_
22K
GND
Circuit configuration for using negative On/Off logic
Monotonic Start-up and Shutdown
The SLDN-12D1Ax module has 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 SLDN-12D1Ax module can start into a prebiased output as long as the prebias voltage is 0.5V less than the
set output voltage.
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Output Voltage Programming
The output voltage of the module is programmable to any voltage from 0.6dc to 5.5Vdc by connecting a resistor
between the Trim and SIG_GND pins of the module. Certain restrictions apply on the output voltage set point
depending on the input voltage. These are shown in the Output Voltage vs. Input Voltage Set Point Area plot in
Fig. 41. The Upper Limit curve shows that for output voltages lower than 1V, the input voltage must be lower
than the maximum of 14.4V. The Lower Limit curve shows that for output voltages higher than 0.6V, the input
voltage needs to be larger than the minimum of 3V.
Figure 41
Output Voltage vs. Input Voltage Set Point Area plot showing limits where the output voltage can be set for
different input voltages.
Figure 42
VIN (+)
VO(+)
VS+
ON/OFF
LOAD
TRIM
Rtrim
SIG _GND
VS-
Circuit configuration for programming output voltage using an external resistor.
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Output Voltage Programming(continued)
Without an external resistor between Trim and SIG_GND pins, the output of the module will be 0.6Vdc.To
calculate the value of the trim resistor, Rtrim for a desired output voltage, should be as per the following equation:
 12

Rtrim  
 k

Vo

0
.
6



Rtrim is the external resistor in kΩ
Vo is the desired output voltage.
Table 1 provides Rtrim values required for some common output voltages.
Table1
VO, set (V)
0.6
0.9
1.0
1.2
1.5
1.8
2.5
3.3
5.0
Rtrim (KΩ)
Open
40
30
20
13.33
10
6.316
4.444
2.727
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.
Remote Sense
The SLDN-12D1Ax power modules has a Remote Sense feature to minimize the effects of distribution losses by
regulating the voltage between the sense pins (VS+ and VS-). The voltage drop between the sense pins and the
VOUT and GND pins of the module should not exceed 0.5V.
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Analog Voltage Margining
Output voltage margining can be implemented in the SLIN-12E2Ax 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.
Figure 43
Vo
Rmargin-down
MODULE
Q2
Trim
Rmargin-up
Rtrim
Q1
GND
Circuit Configuration for margining Output voltage
Digital Output Voltage Margining
Please see the Digital Feature Descriptions section.
Output Voltage Sequencing
The SLDN-12D1Ax module includes a sequencing feature, EZ-SEQUENCE 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.
The voltage applied to the SEQ pin should be scaled down by the same ratio as used to scale the output voltage
down to the reference voltage of the module. This is accomplished by an external resistive divider connected
across the sequencing voltage before it is fed to the SEQ pin as shown in Fig. 44. In addition, a small capacitor
(suggested value 100pF) should be connected across the lower resistor R1.
For all Bel modules, the minimum recommended delay between the ON/OFF signal and the sequencing signal is
10ms to ensure that the module output is ramped up according to the sequencing signal. This ensures that the
module soft-start routine is completed before the sequencing signal is allowed to ramp up .
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Output Voltage Sequencing (continued)
Figure 44
DLynx Module
V
SEQ
20K
SEQ
R1=Rtrim
100 pF
SIG_GND
Circuit showing connection of the sequencing signal to the SEQ pin
When the scaled down sequencing 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 sequencing voltage must be set higher than the
set-point voltage of the module. The output voltage follows the sequencing voltage 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.
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.
Note that in all of modules, the PMBus Output Undervoltage Fault will be tripped when sequencing is employed.
This will be detected using the STATUS_WORD and STATUS_VOUT PMBus commands. In addition, the
SMBALERT# signal will be asserted low as occurs for all faults and warnings. To avoid the module shutting down
due to the Output Undervoltage Fault, the module must be set to continue operation without interruption as the
response to this fault (see the description of the PMBus command VOUT_UV_FAULT_RESPONSE for additional
information).
Overcurrent Protection
To provide protection in a fault (output overload) condition, the unit is 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.
Digital Adjustable Overcurrent Warning
Please see the Digital Feature Descriptions section.
Overtemperature Protection
To provide protection in a fault condition, the unit is equipped with a thermal shutdown circuit. The unit will shut
o
down if the overtemperature threshold of 150 C(typ) is exceeded at the thermal reference point Tref .Once the unit
goes into thermal shutdown it will then wait to cool before attempting to restart.
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Digital Temperature Status via PMBus
Please see the Digital Feature Descriptions section.
Digitally Adjustable Output Over and Under Voltage Protection
Please see the Digital Feature Descriptions section.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout limit, the module operation is disabled. The module will
begin to operate at an input voltage above the undervoltage lockout turn-on threshold.
Digitally Adjustable Input Undervoltage Lockout
Please see the Digital Feature Descriptions section.
Digitally Adjustable Power Good Thresholds
Please see the Digital Feature Descriptions section.
Synchronization
The SLDN-12D1Ax module switching frequency can be synchronized to a signal with an external frequency
within a specified range. Synchronization can be done by using the external signal applied to the SYNC pin of the
module as shown in Fig. 45, with the converter being synchronized by the rising edge of the external signal. The
Electrical Specifications table specifies the requirements of the external SYNC signal. If the SYNC pin is not used,
the module should free run at the default switching frequency. If synchronization is not being used, connect the
SYNC pin to GND.
Figure 45
External source connections to synchronize switching frequency of the module.
Measuring Output Current, Output Voltage and Input Voltage
Please see the Digital Feature Descriptions section.
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Dual Layout
Identical dimensions and pin layout of modules permit migration from one to the other without needing to change
the layout. To support this, 2 separate Trim Resistor locations have to be provided in the layout. As shown in Fig.
46, for the digital modules, the resistor is connected between the TRIM pad and SGND and in the case of the
analog module it is connected between TRIM and GND.
Figure 46
MODULE
TRIM
(PVX012 / PDT012)
Rtrim1
for
Digital
Rtrim2
for
Analog
SIG_GND
GND(Pin 7)
Connections to support either Analog or Digital module on the same layout.
Tunable LoopTM
TM
The SLDN-12D1Ax module has a feature that optimizes transient response of the module called Tunable Loop .
External capacitors are usually added to the output of the module for two reasons: to reduce output ripple and
noise (see Figure 38) 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 VS+ and TRIM pins of the module, as shown in Fig. 47. This R-C allows the user to externally adjust the
voltage loop feedback compensation of the module.
Figure 47
VOUT
VS+
RTune
MODULE
CO
CTune
TRIM
RTrim
SIG_GND
GND
Circuit diagram showing connection of RTUME and CTUNE to tune the control loop of the module.
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Tunable LoopTM(continued)
Recommended values of RTUNE and CTUNE for different output capacitor combinations are given in Table 2. 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 6A to 12A step change (50% of
full load), with an input voltage of 12V.
Please contact your Bel Power technical representative to obtain more details of this feature as well as for
guidelines on how to select the right value of external R-C to tune the module for best transient performance and
stable operation for other output capacitance values.
Table 2
Co
1x47F
2x47F
4x47F
6x47F
RTUNE
330
330
330
330
220
180
CTUNE
100pF
560pF
1500pF
2200pF
10nF
6800pF
10x47F 20x47F
General recommended values of of RTUNE and CTUNE for Vin=12V and various external ceramic capacitor
combinations.
Table 3
Vo
Co
5V
3.3V
5x47F
RTUNE
330
CTUNE
1500pF
99mV
V
2.5V
1x47F + 3x47F +
330F
330F
Polymer
Polymer
330
270
2700pF
58mV
3300pF
47mV
1.8V
1x47F +
2x330F
Polymer
270
5600pF
34mV
1.2V
0.6V
1x47F + 3x47F +
3x330F 6x330F
Polymer Polymer
220
180
10nF
24mV
47nF
12mV
Recommended values of RTUNE and CTUNE to obtain transient deviation of 2% of Vout for a 6A step load with
Vin=12V.
Note: The capacitors used in the Tunable Loop tables are 47 μF/3 mΩ ESR ceramic and 330 μF/12 mΩ ESR
polymer capacitors.
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Digital Feature Descriptions
PMBus Interface Capability
The SLDN-12D1Ax power modules have a PMBus interface that supports both communication and control. The
PMBus Power Management Protocol Specification can be obtained from www.pmbus.org. The modules support
a subset of version 1.1 of the specification (see Table 6 for a list of the specific commands supported). Most
module parameters can be programmed using PMBus and stored as defaults for later use.
All communication over the module PMBus interface must support the Packet Error Checking (PEC) scheme.
The PMBus master must generate the correct PEC byte for all transactions, and check the PEC byte returned by
the module.
The module also supports the SMBALERT response protocol whereby the module can alert the bus master if it
wants to talk. For more information on the SMBus alert response protocol, see the System Management Bus
(SMBus) specification.
The module has non-volatile memory that is used to store configuration settings. Not all settings programmed
into the device are automatically saved into this non-volatile memory, only those specifically identified as capable
of being stored can be saved (see Table 6 for which command parameters can be saved to non-volatile storage).
PMBus Data Format
For commands that set thresholds, voltages or report such quantities, the module supports the “Linear” data
format among the three data formats supported by PMBus. The Linear Data Format is a two byte value with an
11-bit, two’s complement mantissa and a 5-bit, two’s complement exponent. The format of the two data bytes is
shown below:
Data Byte High
7 6 5 4 3
2 1 0 7 6 5 4 3 2 1 0
Exponent
MSB
Data Byte Low
Mantissa
MSB
The value is of the number is then given by
Value = Mantissa x 2 Exponent
PMBus Addressing
The SLDN-12D1Ax modules can be addressed through the PMBus using a device address. The module has 64
possible addresses (0 to 63 in decimal) which can be set using resistors connected from the ADDR0 and ADDR1
pins to SIG_GND. Note that some of these addresses (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 12, 40, 44, 45, 55 in
decimal) are reserved according to the SMBus specifications and may not be useable. The address is set in the
form of two octal (0 to 7) digits, with each pin setting one digit. The ADDR1 pin sets the high order digit and
ADDR0 sets the low order digit. The resistor values suggested for each digit are shown in Table 4 (1% tolerance
resistors are recommended). Note that if either address resistor value is outside the range specified in Table 4,
the module will respond to address 127.
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PMBus Addressing(continued)
Table 4
Digit
0
1
2
3
4
5
6
7
Resistor Value
(KΩ)
10
15.4
23.7
36.5
54.9
84.5
130
200
2
The user must know which I C addresses are reserved in a system for special functions and set the address of
the module to avoid interfering with other system operations. Both 100kHz and 400kHz bus speeds are
supported by the module. Connection for the PMBus interface should follow the High Power DC specifications
given in section 3.1.3 in the SMBus specification V2.0 for the 400kHz bus speed or the Low Power DC
specifications in section 3.1.2. The complete SMBus specification is available from the SMBus web
site,smbus.org.
Figure 48
ADDR1
ADDR0
RADDR0
RADDR1
SIG_GND
Circuit showing connection of resistors used to set the PMBus address of the module.
PMBus Enabled On/Off
The SLDN-12D1Ax module can also be turned on and off via the PMBus interface. The OPERATION command
is used to actually turn the module on and off via the PMBus, while the ON_OFF_CONFIG command configures
the combination of analog ON/OFF pin input and PMBus commands needed to turn the module on and off. Bit [7]
in the OPERATION command data byte enables the module, with the following functions:
0 :
Output is disabled
1 :
Output is enabled
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PMBus Enabled On/Of(continued)
This module uses the lower five bits of the ON_OFF_CONFIG data byte to set various ON/OFF options as
follows:
Access
Function
Default Value
4
r/w
PU
1
3
2
1
0
r/w
r/w
r/w
r
CMD CPR POL CPA
0
1
1
1
PU: Sets the default to either operate any time input power is present or for the ON/OFF to be controlled by the
analog ON/OFF input and the PMBus OPERATION command. This bit is used together with the CP, CMD and
ON bits to determine startup.
Bit
Value
0
1
Action
Module powers up any time power is
present regardless of state of the
analog ON/OFF pin
Module does not power up until
commanded by the analog ON/OFF
pin and the OPERATION command
as programmed in bits [2:0] of the
ON_OFF_CONFIG register.
CMD: The CMD bit controls how the device responds to the OPERATION command.
Bit
Value
0
1
Action
Module ignores the ON bit in the
OPERATION command
Module responds to the ON bit in the
OPERATION command
CPR: Sets the response of the analog ON/OFF pin. This bit is used together with the CMD, PU and ON bits to
determine startup.
Bit
Value
0
1
Action
Module ignores the analog ON/OFF
pin, i.e. ON/OFF is only controlled
through the PMBUS via the
OPERATION command
Module requires the analog ON/OFF
pin to be asserted to start the unit
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PMBus Adjustable Soft Start Rise Time
The soft start rise time can be adjusted in the module via PMBus. When setting this parameter, make sure that
the charging current for output capacitors can be delivered by the module in addition to any load current to avoid
nuisance tripping of the overcurrent protection circuitry during startup. The TON_RISE command sets the rise
time in ms, and allows choosing soft start times between 600μs and 9ms, with possible values listed in Table 5.
Note that the exponent is fixed at -4 (decimal) and the upper two bits of the mantissa are also fixed at 0.
Table 5
Rise
Time
600μs
900μs
1.2ms
1.8ms
2.7ms
4.2ms
6.0ms
9.0ms
Exponent
Mantissa
11100
11100
11100
11100
11100
11100
11100
11100
00000001010
00000001110
00000010011
00000011101
00000101011
00001000011
00001100000
00010010000
Output Voltage Adjustment Using the PMBus
The VOUT_SCALE_LOOP parameter is important for a number of PMBus commands related to output voltage
trimming, margining, over/under voltage protection and the PGOOD thresholds. The output voltage of the module
is set as the combination of the voltage divider formed by RTrim and a 20kΩ upper divider resistor inside the
module, and the internal reference voltage of the module. The reference voltage VREF is nominally set at
600mV, and the output regulation voltage is then given by
 20000  RTrim 
VOUT  
  VREF
RTrim


Hence the SLDN-12D1Ax module output voltage is dependent on the value of RTrim which is connected external
to the module. The information on the output voltage divider ratio is conveyed to the module through the
VOUT_SCALE_LOOP parameter which is calculated as follows:
VOUT _ SCALE _ LOOP 
RTrim
20000  RTrim
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Output Voltage Adjustment Using the PMBus(continued)
The VOUT_SCALE_LOOP parameter is specified using the “Linear” format and two bytes. The upper five bits
[7:3] of the high byte are used to set the exponent which is fixed at –9 (decimal). The remaining three bits of the
high byte [2:0] and the eight bits of the lower byte are used for the mantissa. The default value of the mantissa is
00100000000 corresponding to 256 (decimal), corresponding to a divider ratio of 0.5. The maximum value of the
mantissa is 512 corresponding to a divider ratio of 1. Note that the resolution of the VOUT_SCALE_LOOP
command is 0.2%.
When PMBus commands are used to trim or margin the output voltage, the value of VREF is what is changed
inside the module, which in turn changes the regulated output voltage of the module.
The nominal output voltage of the module can be adjusted with a minimum step size of 0.4% over a ±25% range
from nominal using the VOUT_TRIM command over the PMBus.
The VOUT_TRIM command is used to apply a fixed offset voltage to the output voltage command value using
the “Linear” mode with the exponent fixed at –10 (decimal). The value of the offset voltage is given by
VOUT ( offset )  VOUT _ TRIM  2 10
This offset voltage is added to the voltage set through the divider ratio and nominal VREF to produce the trimmed
output voltage. The valid range in two’s complement for this command is –4000h to 3999h. The high order two
bits of the high byte must both be either 0 or 1. If a value outside of the +/-25% adjustment range is given with
this command, the module will set it’s output voltage to the nominal value (as if VOUT_TRIM had been set to 0),
assert SMBALRT#, set the CML bit in STATUS_BYTE and the invalid data bit in STATUS_CML..
Output Voltage Margining Using the PMBus
The SLDN-12D1Ax module can also have its output voltage margined via PMBus commands. The command
VOUT_MARGIN_HIGH sets the margin high voltage, while the command VOUT_MARGIN_LOW sets the margin
low voltage. Both the VOUT_MARGIN_HIGH and VOUT_MARGIN_LOW commands use the “Linear” mode with
the exponent fixed at –10 (decimal). Two bytes are used for the mantissa with the upper bit [7] of the high byte
fixed at 0. The actual margined output voltage is a combination of the VOUT_MARGIN_HIGH or
VOUT_MARGIN_LOW and the VOUT_TRIM values as shown below.
VOUT ( MH ) 
(VOUT _ MARGIN _ HIGH  VOUT _ TRIM )  210
VOUT ( ML) 
(VOUT _ MARGIN _ LOW  VOUT _ TRIM )  210
Note that the sum of the margin and trim voltages cannot be outside the ±25% window around the nominal output
voltage. The data associated with VOUT_MARGIN_HIGH and VOUT_MARGIN_LOW can be stored to nonvolatile memory using the STORE_DEFAULT_ALL command.
The module is commanded to go to the margined high or low voltages using the OPERATION command. Bits
[5:2] are used to enable margining as follows:
00XX :
0101 :
0110 :
1001 :
1010 :
Margin Off
Margin Low (Ignore Fault)
Margin Low (Act on Fault)
Margin High (Ignore Fault)
Margin High (Act on Fault)
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PMBus Adjustable Overcurrent Warning
The SLDN-12D1Ax module can provide an overcurrent warning via the PMBus. The threshold for the overcurrent
warning can be set using the parameter IOUT_OC_WARN_LIMIT. This command uses the “Linear” data format
with a two byte data word where the upper five bits [7:3] of the high byte represent the exponent and the
remaining three bits of the high byte [2: ent the mantissa. The exponent is fixed at –1 (decimal). The upper five
bits of the mantissa are fixed at 0 while the lower six bits are programmable with a default value of 13.5 (decimal).
The resolution of this warning limit is 500mA. The value of the IOUT_OC_WARN_LIMIT can be stored to nonvolatile memory using the STORE_DEFAULT_ALL0] and the eight bits in the low byte repres command.
Temperature Status via PMBus
The SLDN-12D1Ax module can provide information related to temperature of the module through the
STATUS_TEMPERATURE command. The command returns information about whether the pre-set over
temperature fault threshold and/or the warning threshold have been exceeded.
PMBus Adjustable Output Over and Under Voltage Protection
The SLDN-12D1Ax module has output over and under voltage protection capability. The PMBus command
VOUT_OV_FAULT_LIMIT is used to set the output over voltage threshold from four possible values: 108%,
110%, 112% or 115% of the commanded output voltage. The command VOUT_UV_FAULT_LIMIT sets the
threshold that causes an output under voltage fault and can also be selected from four possible values: 92%,
90%, 88% or 85%. The default values are 112% and 88% of commanded output voltage. Both commands use
two data bytes formatted as two’s complement binary integers. The “Linear” mode is used with the exponent
fixed to –10 (decimal) and the effective over or under voltage trip points given by:
VOUT (OV _ REQ)  (VOUT _ OV _ FAULT _ LIMIT )  2 10
VOUT (UV _ REQ)  (VOUT _ UV _ FAULT _ LIMIT )  2 10
Values within the supported range for over and undervoltage detection thresholds will be set to the nearest fixed
percentage. Note that the correct value for VOUT_SCALE_LOOP must be set in the module for the correct over
or under voltage trip points to be calculated.
In addition to adjustable output voltage protection, the 12A module can also be programmed for the response to
the fault. The VOUT_OV_FAULT RESPONSE and VOUT_UV_FAULT_RESPONSE commands specify the
response to the fault. Both these commands use a single data byte with the possible options as shown below.
1. Continue operation without interruption (Bits [7:6] = 00, Bits [5:3] = xxx)
2. Continue for four switching cycles and then shut down if the fault is still present, followed by no restart or
continuous restart (Bits [7:6] = 01, Bits [5:3] = 000 means no restart, Bits [5:3] = 111 means continuous
restart)
3. Immediate shut down followed by no restart or continuous restart (Bits [7:6] = 10, Bits [5:3] = 000 means
no restart, Bits [5:3] = 111 means continuous restart).
4. Module output is disabled when the fault is present and the output is enabled when the fault no longer exists (Bits
[7:6] = 11, Bits [5:3] = xxx).
Note that separate response choices are possible for output over voltage or under voltage faults.
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PMBus Adjustable Input Undervoltage Lockout
The SLDN-12D1Ax module allows adjustment of the input under voltage lockout and hysteresis. The command
VIN_ON allows setting the input voltage turn on threshold, while the VIN_OFF command sets the input voltage
turn off threshold. For the VIN_ON command, possible values are 2.75V, and 3V to 14V in 0.5V steps. For the
VIN_OFF command, possible values are 2.5V to 14V in 0.5V steps. If other values are entered for either
command, they will be mapped to the closest of the allowed values.
Both the VIN_ON and VIN_OFF commands use the “Linear” format with two data bytes. The upper five bits represent the
exponent (fixed at -2) and the remaining 11 bits represent the mantissa. For the mantissa, the four most significant bits are
fixed at 0.
Power Good
The SLDN-12D1Ax module provides a Power Good (PGOOD) signal that is implemented with an open-drain
output 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 overtemperature, overcurrent or loss of regulation
occurs that would result in the output voltage going outside the specified thresholds. The PGOOD thresholds are
user selectable via the PMBus (the default values are as shown in the Feature Specifications Section). Each
threshold is set up symmetrically above and below the nominal value. The POWER_GOOD_ON command sets
the output voltage level above which PGOOD is asserted (lower threshold). For example, with a 1.2V nominal
output voltage, the POWER_GOOD_ON threshold can set the lower threshold to 1.14 or 1.1V. Doing this will
automatically set the upper thresholds to 1.26 or 1.3V.
The POWER_GOOD_OFF command sets the level below which the PGOOD command is de-asserted. This
command also sets two thresholds symmetrically placed around the nominal output voltage. Normally, the
POWER_GOOD_ON threshold is set higher than the POWER_GOOD_OFF threshold.
Both POWER_GOOD_ON and POWER_GOOD_OFF commands use the “Linear” format with the exponent fixed
at –10 (decimal). The two thresholds are given by
VOUT ( PGOOD _ ON )  ( POWER _ GOOD _ ON )  2 10
VOUT ( PGOOD _ OFF )  ( POWER _ GOOD _ OFF )  2 10
Both commands use two data bytes with bit [7] of the high byte fixed at 0, while the remaining bits are r/w and
used to set the mantissa using two’s complement representation. Both commands also use the
VOUT_SCALE_LOOP parameter so it must be set correctly. The default value of POWER_GOOD_ON is set at
1.1035V and that of the POWER_GOOD_OFF is set at 1.08V. The values associated with these commands can
be stored in non-volatile memory using the STORE_DEFAULT_ALL command.
The PGOOD terminal can be connected through a pullup resistor(suggested value 100 K) to a source of 5VDC
or lower.
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Measurement of Output Current, Output Voltage and Input Voltage
The SLDN-12D1Ax module is capable of measuring key module parameters such as output current and voltage
and input voltage and providing this information through the PMBus interface. Roughly every 200μs, the module
makes 16 measurements each of output current, voltage and input voltage. Average values of of these 16
measurements are then calculated and placed in the appropriate registers. The values in the registers can then
be read using the PMBus interface.
Measuring Output Current Using the PMBus
The SLDN-12D1Ax module measures current by using the inductor winding resistance as a current sense
element. The inductor winding resistance is then the current gain factor used to scale the measured voltage into
a current reading. This gain factor is the argument of the IOUT_CAL_GAIN command, and consists of two bytes
in the linear data format. The exponent uses the upper five bits [7:3] of the high data byte in two-s complement
format and is fixed at –15 (decimal). The remaining 11 bits in two’s complement binary format represent the
mantissa. During manufacture, each module is calibrated by measuring and storing the current gain factor into
non-volatile storage.
The current measurement accuracy is also improved by each module being calibrated during manufacture with
the offset in the current reading. The IOUT_CAL_OFFSET command is used to store and read the current offset.
The argument for this command consists of two bytes composed of a 5-bit exponent (fixed at -4d) and a 11-bit
mantissa. This command has a resolution of 62.5mA and a range of -4000mA to +3937.5mA.
The READ_IOUT command provides module average output current information. This command only supports
positive or current sourced from the module. If the converter is sinking current a reading of 0 is provided. The
READ_IOUT command returns two bytes of data in the linear data format. The exponent uses the upper five bits
[7:3] of the high data byte in two-s complement format and is fixed at –4 (decimal). The remaining 11 bits in two’s
complement binary format represent the mantissa with the 11th bit fixed at 0 since only positive numbers are
considered valid.
Note that the current reading provided by the module is not corrected for temperature. The temperature corrected
current reading for module temperature TModule can be estimated using the following equation where
IOUT_CORR is the temperature corrected value of the current measurement, IREAD_OUT is the module current
measurement value, TIND is the temperature of the inductor winding on the module. Since it may be difficult to
measure TIND, it may be approximated by an estimate of the module temperature.
Measuring Output Voltage Using the PMBus
The SLDN-12D1Ax module can provide output voltage information using the READ_VOUT command. The
command returns two bytes of data all representing the mantissa while the exponent is fixed at -10 (decimal).
During manufacture of the module, offset and gain correction values are written into the non-volatile memory of
the module. The command VOUT_CAL_OFFSET can be used to read and/or write the offset (two bytes
consisting of a 16-bit mantissa in two’s complement format) while the exponent is always fixed at -10 (decimal).
The allowed range for this offset correction is -125 to 124mV. The command VOUT_CAL_GAIN can be used to
read and/or write the gain correction - two bytes consisting of a five-bit exponent (fixed at -8) and a 11-bit
mantissa. The range of this correction factor is -0.125V to +0.121V, with a resolution of 0.004V. The corrected
output voltage reading is then given by:
VOUT ( Final) 
[VOUT ( Initial)  (1  VOUT _ CAL _ GAIN)]
 VOUT _ CAL _ OFFSET
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NON-ISOLATED DC/DC CONVERTERS
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Oct. 11,2012
Measuring Input Voltage Using the PMBus
The SLDN-12D1Ax module can provide output voltage information using the READ_VIN command. The
command returns two bytes of data in the linear format. The upper five bits [7:3] of the high data form the two’s
complement representation of the mantissa which is fixed at –5 (decimal). The remaining 11 bits are used for
th
two’s complement representation of the mantissa, with the 11 bit fixed at zero since only positive numbers are
valid.
During module manufacture, offset and gain correction values are written into the non-volatile memory of the
module. The command VIN_CAL_OFFSET can be used to read and/or write the offset - two bytes consisting of a
five-bit exponent (fixed at -5) and a11-bit mantissa in two’s complement format. The allowed range for this offset
correction is -2 to 1.968V, and the resolution is 32mV. The command VIN_CAL_GAIN can be used to read
and/or write the gain correction - two bytes consisting of a five-bit exponent (fixed at -8) and a 11-bit mantissa.
The range of this correction factor is -0.125V to +0.121V, with a resolution of 0.004V. The corrected output
voltage reading is then given by:
VIN ( Final) 
[VIN ( Initial)  (1  VIN _ CAL _ GAIN)]
 VIN _ CAL _ OFFSET
Reading the Status of the Module using the PMBus
The SLDN-12D1Ax module supports a number of status information commands implemented in PMBus.
However, not all features are supported in these commands. A 1 in the bit position indicates the fault that is
flagged.
STATUS_BYTE : Returns one byte of information with a summary of the most critical device faults.
Bit
Position
7
6
5
4
3
2
1
0
Flag
X
OFF
VOUT Overvoltage
IOUT Overcurrent
VIN Undervoltage
Temperature
CML (Comm. Memory
Fault)
None of the above
Default
Value
0
0
0
0
0
0
0
0
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NON-ISOLATED DC/DC CONVERTERS
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Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Reading the Status of the Module using the PMBus(continued)
STATUS_WORD : Returns two bytes of information with a summary of the module’s fault/warning conditions.
Bit
Position
7
6
5
4
3
2
1
0
Bit
Position
7
6
5
4
3
2
1
0
Flag
X
OFF
VOUT Overvoltage
IOUT Overcurrent
VIN Undervoltage
Temperature
CML (Comm. Memory
Fault)
None of the above
Flag
VOUT fault or warning
IOUT fault or warning
X
X
POWER_GOOD# (is
negated)
X
X
X
Default
Value
0
0
0
0
0
0
0
0
Default
Value
0
0
0
0
0
0
0
0
STATUS_VOUT : Returns one byte of information relating to the status of the module’s output voltage related
faults.
Bit
Position
7
6
5
4
3
2
1
0
Flag
VOUT OV Fault
X
X
VOUT UV Fault
X
X
X
X
Default
Value
0
0
0
0
0
0
0
0
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NON-ISOLATED DC/DC CONVERTERS
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Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Reading the Status of the Module using the PMBus(continued)
STATUS_IOUT : Returns one byte of information relating to the status of the module’s output voltage related
faults.
Bit
Position
7
6
5
4
3
2
1
0
Flag
IOUT OC Fault
X
IOUT OC Warning
X
X
X
X
X
Default
Value
0
0
0
0
0
0
0
0
STATUS_TEMPERATURE : Returns one byte of information relating to the status of the module’s
temperature related faults.
Bit
Position
7
6
5
4
3
2
1
0
Flag
OT Fault
OT Warning
X
X
X
X
X
X
Default
Value
0
0
0
0
0
0
0
0
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NON-ISOLATED DC/DC CONVERTERS
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Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Reading the Status of the Module using the PMBus(continued)
STATUS_CML : Returns one byte of information relating to the status of the module’s communication related
faults.
Bit
Position
7
6
5
4
3
2
1
0
Flag
Invalid/Unsupported
Command
Invalid/Unsupported
Command
Packet Error Check Failed
X
X
X
Other Communication
Fault
X
Default
Value
0
0
0
0
0
0
0
0
MFR_VIN_MIN : Returns minimum input voltage as two data bytes of information in Linear format (upper five bits
are exponent – fixed at -2, and lower 11 bits are mantissa in two’s complement format – fixed at 12)
MFR_VOUT_MIN : Returns minimum output voltage as two data bytes of information in Linear format (upper five
bits are exponent – fixed at -10, and lower 11 bits are mantissa in two’s complement format – fixed at 614)
MFR_SPECIFIC_00 : Returns information related to the type of module and revision number. Bits [7:2] in the
Low Byte indicate the module type (000000 corresponds to the PDT012 series of module), while bits [7:3]
indicate the revision number of the module.
Bit
Position
7:2
1:0
Flag
Module Name
Reserved
Default
Value
000000
10
Bit
Default
Flag
Position
Value
7:3
Module Revision Number None
2:0
Reserved
000
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NON-ISOLATED DC/DC CONVERTERS
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Bel Power Inc., a subsidiary of Bel Fuse Inc.
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Summary of Supported PMBus Commands
Please refer to the PMBus 1.1 specification for more details of these commands.
Table 6
Hex
Code
01
Command
OPERATION
Non-Volatile
Memory
Storage
Brief Description
Turn Module on or off. Also used to margin the output voltage
Unsigned Binary
Format
7
6
5
4
3
2
Bit Position
r/w
r
r/w
r/w
r/w
r/w
Access
On
X
Margin
Function
0
0
0
0
0
0
Default Value
1
r
X
X
0
r
X
X
02
ON_OFF_CONFIG
Configures the ON/OFF functionality as a combination of analog ON/OFF pin and
PMBus commands
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r/w
r/w
r/w
r/w
r
Access
X
X
X
pu
cmd
pol
cpa
X
Function
0
0
0
1
0
1
1
1
Default Value
03
CLEAR_FAULTS
Clear any fault bits that may have been set, also releases the SMBALERT# signal if
the device has been asserting it.
10
WRITE_PROTECT
Used to control writing to the module via PMBus. Copies the current register setting
in the module whose command code matches the value in the data byte into nonvolatile memory (EEPROM) on the module
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
x
x
x
x
x
Access
bit7
bit6
bit5
X
X
X
X
X
Function
0
0
0
X
X
X
X
X
Default Value
Bit5: 0 – Enables all writes as permitted in bit6 or bit7
1 – Disables all writes except the WRITE_PROTECT, OPERATION
and ON_OFF_CONFIG (bit 6 and bit7 must be 0)
Bit 6: 0 – Enables all writes as permitted in bit5 or bit7
1 – Disables all writes except for the WRITE_PROTECT and
OPERATION commands (bit5 and bit7 must be 0)
Bit7: 0 – Enables all writes as permitted in bit5 or bit6
1 – Disables all writes except for the WRITE_PROTECT command
(bit5 and bit6 must be 0)
11
STORE_DEFAULT_ALL
12
RESTORE_DEFAULT_ALL
13
STORE_DEFAULT_CODE
14
RESTORE_DEFAULT_CODE
20
VOUT_MODE
YES
YES
Copies all current register settings in the module into non-volatile memory
(EEPROM) on the module. Takes about 50ms for the command to execute.
Restores all current register settings in the module from values in the module nonvolatile memory (EEPROM)
Copies the current register setting in the module whose command code matches the
value in the data byte into non-volatile memory (EEPROM) on the module
7
6
5
4
3
2
1
0
Bit Position
w
w
w
w
w
w
w
w
Access
Command code
Function
Restores the current register setting in the module whose command code matches
the value in the data byte from the value in the module non-volatile memory
(EEPROM)
7
6
5
4
3
2
1
0
Bit Position
w
w
w
w
w
w
w
w
Access
Command code
Function
The module has MODE set to Linear and Exponent set to -10. These values cannot
be changed
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mode
Exponent
Function
0
0
0
1
0
1
1
0
Default Value
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Hex
Code
Command
22
VOUT_TRIM
25
VOUT_MARGIN_HIGH
26
29
35
VOUT_MARGIN_LOW
Non-Volatile
Memory
Storage
Brief Description
Apply a fixed offset voltage to the output voltage command value. Exponent is
fixed at -10.
Format
Linear, two’s complement binary
Bit Position
7
6
5
4
3
2
1
0
Access
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
High Byte
Default Value
0
0
0
0
0
0
0
0
Bit Position
7
6
5
4
3
2
1
0
Access
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
Low Byte
Default Value
0
0
0
0
0
0
0
0
Sets the target voltage for margining the output high. Exponent is fixed at -10.
Format
Linear, two’s complement binary
Bit Position
7
6
5
4
3
2
1
0
Access
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
High Byte
Default Value
0
0
0
0
0
1
0
1
Bit Position
7
6
5
4
3
2
1
0
Access
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
Low Byte
Default Value
0
1
0
0
0
1
1
1
Sets the target voltage for margining the output low. Exponent is fixed at
Format
Linear, two’s complement binary
Bit Position
7
6
5
4
3
2
1
Access
r
r/w
r/w
r/w
r/w
r/w
r/w
Function
High Byte
Default Value
0
0
0
0
0
1
0
Bit Position
7
6
5
4
3
2
1
Access
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
Low Byte
Default Value
0
1
0
1
0
0
0
YES
YES
-10
0
r/w
0
0
r/w
YES
1
VOUT_SCALE_LOOP
Sets the scaling of the output voltage – equal to the feedback resistor divider ratio
Format
Linear, two’s complement binary
Bit Position
7
6
5
4
3
2
1
0
Access
r
r
r
r
r
r
r/w
r/w
Function
Exponent
Mantissa
Default Value
1
0
1
1
1
0
0
1
Bit Position
7
6
5
4
3
2
1
0
Access
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
Mantissa
Default Value
0
0
0
0
0
0
0
0
YES
VIN_ON
Sets the value of input voltage at which the module turns on
Format
Linear, two’s complement binary
Bit Position
7
6
5
4
3
2
1
0
Access
r
r
r
r
r
r
r
r
Function
Exponent
Mantissa
Default Value
1
1
1
1
0
0
0
0
Bit Position
7
6
5
4
3
2
1
0
Access
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Function
Mantissa
Default Value
0
0
0
0
1
0
1
1
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
35
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
36
38
39
40
41
Command
Non-Volatile
Memory
Storage
Brief Description
VIN_OFF
Sets the value of input voltage at which the module turns off
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
1
1
1
1
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
0
0
1
0
1
0
Default Value
YES
IOUT_CAL_GAIN
Returns the value of the gain correction term used to correct the measured output
current
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r/w
Access
Exponent
Mantissa
Function
1
0
0
0
1
0
0
V
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
V: Variable based on factory calibration
Default Value
YES
IOUT_CAL_OFFSET
Returns the value of the offset correction term used to correct the measured output
current
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r/w
r
r
Access
Exponent
Mantissa
Function
1
1
1
0
0
V
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
V: Variable based on factory calibration
Default Value
YES
Sets the voltage level for an output overvoltage fault. Exponent is fixed at
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
Bit Position
r
r/w
r/w
r/w
r/w
r/w
r/w
Access
High Byte
Function
0
0
0
0
0
1
0
Default Value
7
6
5
4
3
2
1
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Low Byte
Function
0
0
0
0
1
0
1
Default Value
YES
VOUT_OV_FAULT_LIMIT
VOUT_OV_FAULT_RESPONSE
-10.
0
r/w
1
0
r/w
0
Instructs the module on what action to take in response to a output overvoltage fault
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r
r
r
Access
RSP RSP
RS[2] RS[1] RS[0]
X
X
X
Function
[1]
[0]
1
1
1
1
1
1
0
0
Default Value
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
36
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
44
45
4A
5E
5F
Command
Brief Description
Non-Volatile
Memory
Storage
VOUT_UV_FAULT_LIMIT
Sets the voltage level for an output undervoltage fault. Exponent is fixed at -10.
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
High Byte
Function
0
0
0
0
0
1
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Low Byte
Function
1
0
0
0
1
1
1
1
Default Value
YES
VOUT_UV_FAULT_RESPONSE
Instructs the module on what action to take in response to a output undervoltage
fault
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r
r
r
Access
RSP RSP
RS[2] RS[1] RS[0]
X
X
X
Function
[1]
[0]
0
0
0
0
0
1
0
0
Default Value
YES
IOUT_OC_WARN_LIMIT
Sets the output overcurrent warning level in A
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
1
1
1
1
1
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
0
1
1
0
1
1
Default Value
YES
POWER_GOOD_ON
Sets the output voltage level at which the PGOOD pin is asserted high. Exponent is
fixed at -10.
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
High Byte
Function
0
0
0
0
0
1
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Low Byte
Function
0
1
1
0
1
0
1
0
Default Value
YES
POWER_GOOD_OFF
Sets the output voltage level at which the PGOOD pin is de-asserted low. Exponent
is fixed at -10.
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
High Byte
Function
0
0
0
0
0
1
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Low Byte
Function
0
1
0
1
0
0
1
0
Default Value
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
37
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
61
78
79
7A
7B
7D
Command
TON_RISE
Non-Volatile
Memory
Storage
Brief Description
Sets the rise time of the output voltage during startup
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r/w
Access
Exponent
Mantissa
Function
1
1
1
0
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
1
0
1
0
1
0
Default Value
STATUS_BYTE
Returns one byte of information with a summary of the most critical module faults
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
VOUT IOUT VIN_
OTHE
X
OFF
TEMP CML
Flag
_OV _OC UV
R
0
0
0
0
0
0
0
0
Default Value
STATUS_WORD
Returns two bytes of information with a summary of the module’s fault/warning
conditions
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
IOUT
PGOO
VOUT
X
X
X
X
X
Flag
_OC
D
0
0
0
0
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
VOUT IOUT VIN_
OTHE
X OFF
TEMP CML
Flag
_OV _OC UV
R
0
0
0
0
0
0
0
0
Default Value
STATUS_VOUT
Returns one byte of information with the status of the module’s output voltage
related faults
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
VOUT_OV X
X VOUT_UV X
X
X
X
Flag
0
0
0
0
0
0
0
0
Default Value
STATUS_IOUT
Returns one byte of information with the status of the module’s output current
related faults
Unsigned Binary
Format
7
6 5 4
3
2 1
Bit Position
r
r r r
r
r r
Access
IOUT_OC X X X IOUT_OC_WARN X X
Flag
0
0 0 0
0
0 0
Default Value
STATUS_TEMPERATURE
YES
0
r
X
0
Returns one byte of information with the status of the module’s temperature related
faults
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
OT_FAULT OT_WARN X
X
X
X
X
X
Flag
0
0
0
0
0
0
0
0
Default Value
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
38
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
Command
7E
STATUS_CML
88
READ_VIN
8B
8C
98
A0
Non-Volatile
Memory
Storage
Brief Description
Returns one byte of information with the status of the module’s communication
related faults
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Other
Invalid
Invalid PEC
X
X
X
X
Comm
Flag
Command Data Fail
Fault
0
0
0
0
0
0
0
0
Default Value
Returns the value of the input voltage applied to the module
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
1
1
0
1
1
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mantissa
Function
0
0
0
0
0
0
0
0
Default Value
READ_VOUT
Returns the value of the output voltage of the module. Exponent is fixed at -10.
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mantissa
Function
0
0
0
0
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mantissa
Function
0
0
0
0
0
0
0
0
Default Value
READ_IOUT
Returns the value of the output current of the module
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
Bit Position
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
1
1
1
0
0
0
0
Default Value
7
6
5
4
3
2
1
Bit Position
r
r
r
r
r
r
r
Access
Mantissa
Function
0
0
0
0
0
0
0
Default Value
PMBUS_REVISION
MFR_VIN_MIN
0
r
0
0
r
0
Returns one byte indicating the module is compliant to PMBus Spec. 1.1 (read
only)
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
0
0
0
1
0
0
0
1
Default Value
YES
Returns the minimum input voltage the module is specified to operate at (read only)
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
1
1
1
1
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mantissa
Function
0
0
0
0
1
1
0
0
Default Value
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
39
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
Command
A4
MFR_VOUT_MIN
D0
MFR_SPECIFIC_00
D4
VOUT_CAL_OFFSET
D5
VOUT_CAL_GAIN
D6
VIN_CAL_OFFSET
Brief Description
Returns the minimum output voltage possible from the module(read only).
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Exponent
Mantissa
Function
0
0
0
0
0
0
1
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Mantissa
Function
0
1
1
0
0
1
1
0
Default Value
Returns module name information(read only).
Unsigned Binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Reserved
Function
1
1
1
0
1
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r
Access
Module Name
Reserved
Function
0
0
0
0
0
0
1
0
Default Value
Applies an offset to the READ_VOUT command results to calibrate out offset
errors in module measurements of the output voltage (between-125mV and
+124mV).Exponent is fixed at -10..
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r/w
r
r
r
r
r
r
r
Access
Mantissa
Function
V
0
0
0
0
0
0
0
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
V
V
V
V
V
V
V
V
Default Value
Applies a gain correction to the READ_VOUT command results to calibrate out
gain errors in module measurements of the output voltage (between-0.125 and
0.121).
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r
r
r
r/w
Access
Exponent
Mantissa
Function
1
1
0
0
0
0
0
V
Default Value
7
6
5
4
3
2
1
0
Bit Position
r/w
r/w
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
V
V
V
V
V
V
V
V
Default Value
Applies an offset correction to the READ_VIN command results to calibrate out
offset errors in module measurements of the input voltage (between -2V and
+1.968).
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r/w
r
r
r/w
Access
Exponent
Mantissa
Function
1
1
0
1
V
0
0
V
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r/w
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
V
V
V
V
V
V
Default Value
Non-Volatile
Memory
Storage
YES
YES
YES
YES
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
40
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Hex
Code
D7
Command
Brief Description
Non-Volatile
Memory
Storage
VIN_CAL_GAIN
Applies a gain correction to the READ_VIN command results to calibrate out gain errors
in module measurements of the input voltage (between -0.125 and 0.121)
Linear, two’s complement binary
Format
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r
r/w
r
r
r/w
Access
Exponent
Mantissa
Function
1
1
0
0
V
0
0
V
Default Value
7
6
5
4
3
2
1
0
Bit Position
r
r
r
r/w
r/w
r/w
r/w
r/w
Access
Mantissa
Function
0
0
0
V
V
V
V
V
Default Value
YES
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
41
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Thermal Considerations
The SLDN-12D1Ax 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 in Figure 49. The preferred airflow direction for the module is in Figure 50.
Figure 49
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 are also shown in Figure 50. For reliable operation
the temperatures at these points should not exceed 120oC. The output power of the module should not exceed
the rated power of the module (Vo,set x Io,max).
Please refer to the Application Note “Thermal Characterization Process For Open-Frame Board-Mounted Power
Modules” for a detailed discussion of thermal aspects including maximum device temperatures.
Figure 50
Preferred airflow direction and location of hot-spot of the module(Tref).
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
42
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Example Application Circuit
Requirements:
Vin:
12V
Vout:
1.8V
Iout:
9A max., worst case load transient is from 6A to 9A
Vout:
1.5% of Vout (27mV) for worst case load transient
Vin, ripple
1.5% of Vin (180mV, p-p)
Vin+
Vout+
VI
N
PGOOD
VOUT
VS+
RTUNE
MODULE
SEQ
CI2
TRIM
ADDR0
A
SMBALRT#
ADDR1
CI1
Q1
GND
CTUNE
CL
K
DAT
ON/OFF
CO1
CO2
RTrim
RADDR1
RADDR0
SIG_GND
GND VS-
CI1
2x22F/16V ceramic capacitor (e.g. Murata GRM32ER61C226KE20)
CI2
47F/16V bulk electrolytic
CO1
2 x 47F/6.3V ceramic capacitor (e.g. Murata GRM31CR60J476ME19)
CO2
1 x 330F/6.3V Polymer (e.g. Sanyo Poscap)
CTune
3300pF ceramic capacitor (can be 1206, 0805 or 0603 size)
RTune
270 ohms SMT resistor (can be 1206, 0805 or 0603 size)
RTrim
10k 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
43
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Mechanical Outline
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.)
PIN
1
FUNCTION
ON/OFF
PIN
10
FUNCTION
PGOOD
2
VIN
11
SYNC
3
GND
12
VS-
4
VOUT
13
SIG. GND
5
VS+ (SENSE)
14
SMBALERT
6
TRIM
15
DATA
7
GND
16
ADDR0
8
CLK
17
ADDR1
9
SEQ
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
44
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Recommended Pad Layout
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.)
PIN FUNCTION PIN FUNCTION
1
ON/OFF
10
PGOOD
2
VIN
11
SYNC
3
GND
12
VS4
VOUT
13
SIG_GND
5
VS+ (SENSE) 14 SMBALERT
6
TRIM
15
DATA
7
GND
16
ADDR0
8
CLK
17
ADDR1
9
SEQ
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
45
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Packaging Details
The SLDN-12D1Ax 12A modules are supplied in tape & reel as standard. Modules are shipped in quantities of
200 modules per reel.
All Dimensions are in millimeters and (in inches).
Reel Dimensions:
Outside Dimensions:
330.2 mm (13.00)
Inside Dimensions:
177.8 mm (7.00”)
Tape Width:
24.00 mm (0.945”)
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
46
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Surface Mount Information
Pick and Place
The SLDN-12D1Ax 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
o
is able to withstand reflow temperatures of up to 300 C. The label also carries product information such as
product code, serial number and the location of manufacture.
Nozzle Recommendations
The SLDN-12D1Ax module weight has been kept to a minimum by using open frame construction. Variables
such as nozzle size, tip style, vacuum pressure and 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 7 mm.
Bottom Side / First Side Assembly
This SLDN-12D1Ax 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.
Lead Free Soldering
The SLDN-12D1Ax modules are lead-free (Pb-free) and RoHS compliant and fully compatible in a Pb-free
soldering process. Failure to observe the instructions below may result in the failure of or cause damage to the
modules and can adversely affect long-term reliability.
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 (table 4-2). The suggested Pb-free solder paste is Sn/Ag/Cu (SAC). The recommended linear reflow
profile using Sn/Ag/Cu solder is shown in Fig. 50. Soldering outside of the recommended profile requires testing
to verify results and performance.
MSL Rating
The SLDN-12D1Ax modules have a MSL rating of 2.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
47
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Surface Mount Information(continued)
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.
Figure51
300
Per J-STD-020 Rev. C
Peak Temp 260°C
Reflow Temp (°C)
250
200
* Min. Time Above 235°C
15 Seconds
150
Heating Zone
1°C/Second
Cooling
Zone
*Time Above 217°C
60 Seconds
100
50
0
Reflow Time (Seconds)
Recommended linear reflow profile using Sn/Ag/Cu solder.
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. For guidance on appropriate soldering, cleaning and drying procedures, refer to
Board Mounted Power Modules: Soldering and Cleaning Application Note (AN04-001).
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302  Tel 201-432-0463  Fax 201-432-9542  www.belfuse.com
48
NON-ISOLATED DC/DC CONVERTERS
3 Vdc – 14.4 Vdc Input, 0.45 Vdc - 5.5 Vdc /12 A Outputs
Bel Power Inc., a subsidiary of Bel Fuse Inc.
Oct. 11,2012
Revision History
Date
Revision
Changes Detail
Approval
2011-10-19
A
First release
HL LU
2012-05-09
B
Adding patent information.
HL LU
RoHS Compliance
Complies with the European Directive 2002/95/EC, calling for the elimination of lead and
other hazardous substances from electronic products.
Bel Power Digital Non-Isolated DC-DC products use technology licensed from Power-One, protected by US patents: US20040246754,
US2004090219A1, US2004093533A1, US2004123164A1, US2004123167A1, US2004178780A1, US2004179382A1, US20050200344,
US20050223252, US2005289373A1, US20060061214, US2006015616A1, US20060174145, US20070226526, US20070234095,
US20070240000, US20080052551, US20080072080, US20080186006, US6741099, US6788036, US6936999, US6949916, US7000125,
US7049798, US7068021, US7080265, US7249267, US7266709, US7315156, US7372682, US7373527, US7394445, US7456617,
US7459892, US7493504, US7526660.
Outside the US the Power-One licensed technology is protected by patents: AU3287379AA, AU3287437AA, AU3290643AA,
AU3291357AA, CN10371856C, CN1045261OC, CN10458656C, CN10459360C, CN10465848C, CN11069332A, CN11124619A,
CN11346682A, CN1685299A, CN1685459A, CN1685582A, CN1685583A, CN1698023A, CN1802619A, EP1561156A1, EP1561268A2,
EP1576710A1, EP1576711A1, EP1604254A4, EP1604264A4, EP1714369A2, EP1745536A4, EP1769382A4, EP1899789A2,
EP1984801A2, W004044718A1, W004045042A3, W004045042C1, W004062061 A1, W004062062A1, W004070780A3, W004084390A3,
W004084391A3, W005079227A3, W005081771A3, W006019569A3, W02007001584A3, W02007094935A3
2012 Bel Fuse Inc. Specifications subject to change without notice.101112
51
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