NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 SLIN-20E1Ax RoHS Compliant Rev.D Features • Wide Input Voltage Range • Ability to Sink and Source Current • Fixed Switching Frequency • Over Temperature Protection • Power Good Signal • Output Over Current Protection • • • Remote Sense • Remote On/Off TM (a registered trademark of Lineage Power Systems) to Tunable Loop Optimize Dynamic output voltage response Flexible output voltage sequencing • Fixed switching frequency and ability to synchronize with external clock • Class 1, Category 2, Non-Isolated DC/DC Converter (refer to IPC-9592) • Compliant to RoHS EU Directive 2002/95/EC • Compatible in a Pb-free or SnPb reflow environment • UL* 60950-1Recognized, CSA† C22.2 No. 60950-1-03 Certified • VDE‡ 0805:2001-12 (EN60950-1) Licensed Applications • Distributed power architectures • Servers and storage applications • Intermediate bus voltage applications • Networking equipment • Telecommunications equipment • Industrial equipment Description The SLIN-20E1Ax power modules are non-isolated dc-dc converters that can deliver up to 20A of output current. These modules operate over a wide range of input voltage (VIN = 4.5Vdc-14Vdc) and provide a precisely regulated output voltage from 0.69Vdc to 5.5Vdc, programmable via an external resistor. Two new features added with this family of products are frequency synchronization and the Tunable LoopTM. Other features include remote On/Off, adjustable output voltage, over current and over temperature protection, power good and output voltage sequencing. The Tunable LoopTM 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 0.69 Vdc - 5.5 Vdc 4.5 Vdc - 14 Vdc Max. Output Current 20 A Typical Efficiency 90% Model Number Active High SLIN-20E1A0 Model Number Active Low SLIN-20E1AL 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Part Number Explanation S LIN – 20 E 1A 0 1 2 3 4 5 6 1---Surface mount 2---Series code 3---Output current (20A) 4--- Wide input voltage range (4.5-14V) 5--- Wide output voltage range (0.69-5.5V) 6--- Enable, active high, change “0” to “L” means active low Absolute Maximum Ratings Min Typ Max Unit Continuous Input Voltage -0.3 - 15 V Voltage on SEQ terminal, SYNC and PG terminals -0.3 - 6 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 Parameter Operating Input Voltage Min 4.5 Typ - Max 14 Unit V Input Current (full load) - - 20 A - 42 - mA Vo=0.69V, VIN=10V, IO=0, module enabled - 74 - mA Vo=3.3V, VIN=12V, IO=0, module enabled Input Stand-by Current - 3 - mA VIN = 12V, module disabled Input Reflected Ripple Current (pk-pk) - 43 - mA 5Hz to 20MHz, 1μH source impedance; VIN =4.5 to 14V, IO= IOmax I2t Inrush Current Transient - - 1 A2s Input Ripple Rejection (120Hz) - 45 - dB Turn-on Threshold - 4.45 - V Turn-off Threshold - 4.2 - V Hysteresis - 0.25 - V Input Current (no load) Notes VIN=4.5V to 14V 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 20A. 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, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Output Specifications Parameter Min Typ Max Unit Output Voltage Set Point -1.5 - +1.5 %Vo,set Output Voltage -2.5 - +2.5 %Vo,set Adjustment Range1 0.69 - 5.5 V - - 0.5 V VO ≥ 2.5V VO < 2.5V - - 10 5 mV mV VO ≥ 2.5V VO < 2.5V - - 0.4 10 %Vo,set mV VIN=VIN, min to VIN, max Temperature Regulation (-40°C to +85°C) - - 0.5 %Vo,set VO < 2.5V, Tref=TA, min to TA, max Ripple and Noise (pk-pk) - 30 80 mV Ripple and Noise (rms) - 14 28 mV Output Current Range 0 - 20 A Output DC Current Limit - 120 - %Io,max Output Short-Circuit Current - 2.6 - A Vo≤250mV, Hiccup Mode 0 0 0 - 200 1000 10000 uF uF uF Without the Tunable LoopTM With the Tunable LoopTM With the Tunable LoopTM - 2 - mS 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) - 2 - mS 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) Output voltage Rise time - 5 - mS time for Vo to rise from 10% of Vo, set to 90% of Vo, set Output voltage overshoot - - 3 %Vo,set Vin=Vin, min to Vin, max, Io=Io, min to Io, max, With or without maximum external capacitance Remote Sense Range Notes Over all operating input voltage, resistive load, and temperature conditions until end of life selected by an external resistor Load Regulation IO=IO, min to IO, max Line Regulation 5Hz to 20MHz BW, VIN=VIN, nom and IO=IO, min to IO, max Co = 0.1μF // 10 μF ceramic capacitors) Hiccup Mode 2 Output Capacitance ESR≥ 1 mΩ ESR≥0.15 mΩ ESR≥ 10 mΩ Turn-On Delay Time Dynamic Load Response △V50%~100% Peak Deviation - 380 - mV of Max Load Settling Time - 30 - uS △V100%~50% Peak Deviation - 300 - mV of Max Load Settling Time - 30 - uS di/dt=10A/us, Vin=Vin,nom, Vo=1.5V, Ta=25°C, Co=0 Notes: 1. Some output voltages may not be possible depending on the input voltage. 2. External capacitors may require using the new Tunable LoopTM feature to ensure that the module is stable as well as getting the best transient response (See the Tunable LoopTM 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 General Specifications Parameter Min Typ Max Unit - 72.1 81.3 85.7 88.0 89.7 91.8 - % % % % % % Switching Frequency - 550 - kHz Over Temperature Protection - 135 - °C 10 - - mS - - 150 100 mV mV 84 - 7 116 50 %Vo,set Ω - 6.05 - g Notes Efficiency Vo=0.69V Vo=1.2V Vo=1.8V Vo=2.5V Vo=3.3V Vo=5.0V Sequencing Delay time Tracking Accuracy Power-Up: 2V/ms Power-Down: 2V/ms PGOOD (Power Good) Output Voltage Limit for PGOOD Pulldown resistance of PGOOD pin Weight MTBF 14,262,200 hours hours 1.30 x 0.53 x 0.334 33.02 x 13.46 x 8.5 - Vin= 12Vdc, Ta=25°C Io=Io, max , Vo= Vo,set Delay from VIN, min to application of voltage on SEQ pin Vin, min to Vin, max; Io, min to Io, max, Vseq < Vo Signal Interface Open Drain, Vsupply ≤ 5Vdc Calculated Per Bell Core SR-332 (Io=0.8Io, max, Vo=5,V Ta=40°C, Telecordia Method Issue 2, Method I Case 3) Dimensions Inches (L × W × H) Millimeters (L × W × H) Frequency Synchronization Synchronization Frequency Range 520 - 600 KHz High-Level Input Voltage 2.5 - - V Low-Level Input Voltage - - 0.8 V Input Current, SYNC - - 1 mA Minimum Pulse Width, SYNC 250 - - nS Minimum Setup/Hold Time, SYNC 250 - - 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Efficiency Data 90 95 90 EFFICIENCY, η (%) EFFICIENCY, η (%) 85 80 Vin=5V Vin=7V 75 Vin=10V 70 85 Vin=4.5V 80 Vin=12V 70 0 5 10 15 20 0 5 OUTPUT CURRENT, IO (A) 15 20 Vo=1.2V 100 95 95 EFFICIENCY, η (%) 90 EFFICIENCY, η (%)) 10 OUTPUT CURRENT, IO (A) Vo=0.69V Vin=4.5V 85 Vin=12V Vin=14V 80 75 70 90 Vin=4.5V 85 Vin=12V Vin=14V 80 75 70 0 5 10 15 0 20 OUTPUT CURRENT, IO (A) 5 15 20 Vo=2.5V 100 95 95 EFFICIENCY, η (%) 100 90 Vin=4.5V Vin=12V 85 10 OUTPUT CURRENT, IO (A) Vo=1.8V EFFICIENCY, η (%)) Vin=14V 75 Vin=14V 80 75 70 90 Vin=4.5V Vin=12V Vin=14V 85 80 75 70 0 5 10 OUTPUT CURRENT, IO (A) Vo=3.3V 15 20 0 5 10 15 20 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 22 22 20 20 OUTPUT CURRENT, Io (A) OUTPUT CURRENT, Io (A) Thermal Derating Curves 18 16 2m/s (400LFM) 14 1m/s (200LFM) 0.5m/s (100LFM) 12 NC 10 8 6 25 35 45 55 65 75 18 16 2m/s (400LFM) 14 1m/s (200LFM) 12 0.5m/s (100LFM) 10 NC 8 6 85 25 O 35 20 20 OUTPUT CURRENT, Io (A) OUTPUT CURRENT, Io (A) 22 18 16 2m/s (400LFM) 1m/s (200LFM) 0.5m/s (100LFM) 10 NC 8 6 35 45 55 65 75 16 14 2m/s (400LFM) 12 1m/s (200LFM) 10 0.5m/s (100LFM) 8 25 35 20 OUTPUT CURRENT, Io (A) OUTPUT CURRENT, Io (A) 20 18 16 2m/s (400LFM) 1m/s (200LFM) 0.5m/s (100LFM) NC 6 35 45 55 65 75 O AMBIENT TEMPERATURE, TA C Vo=3.3V 65 75 85 Vo=2.5V 22 25 55 AMBIENT TEMPERATURE, TA C 22 8 45 O Vo=1.8V 10 NC 6 85 AMBIENT TEMPERATURE, TA C 12 85 18 O 14 75 Vo=1.2V 22 25 65 AMBIENT TEMPERATURE, TA C Vo=0.69V 12 55 O AMBIENT TEMPERATURE, TA C 14 45 85 18 16 2m/s (400LFM) 14 12 1m/s (200LFM) 10 8 0.5m/s (100LFM) NC 6 25 35 45 55 65 75 85 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs October 8, 2009 Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. OUTPUT VOLTAGE VO (V) (20mV/div) OUTPUT VOLTAGE VO (V) (10mV/div) Ripple and Noise Waveforms TIME, t (1μs/div) TIME, t (1μs/div) Vo=1.2V, Io = Io,max OUTPUT VOLTAGE VO (V) (20mV/div) OUTPUT VOLTAGE VO (V) (20mV/div) Vo=0.69V, Io = Io,max TIME, t (1μs/div) TIME, t (1μs/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 (1μs/div) Vo=3.3V, Io = Io,max TIME, t (1μs/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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 OUTPUT VOLTAGE VO (V) (200mV/div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. Vo=1.2V TIME, t (20μs /div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. Vo=2.5V OUTPUT VOLTAGE VO (V) (200mV/div) OUTPUT VOLTAGE VO (V) (200mV/div) OUTPUT CURRENT, IO (A) (5Adiv) OUTPUT VOLTAGE VO (V) (200mV/div) OUTPUT CURRENT, IO (A) (5Adiv) TIME, t (20μs /div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. Vo=1.8V OUTPUT CURRENT, IO (A) (5Adiv) TIME, t (20μs /div) OUTPUT VOLTAGE VO (V) (200mV/div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. Vo=0.69V OUTPUT CURRENT, IO (A) (5Adiv) TIME, t (20μs /div) TIME, t (20μs /div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. Vo=3.3V OUTPUT CURRENT, IO (A) (5Adiv) OUTPUT CURRENT, IO (A) (5Adiv) OUTPUT VOLTAGE VO (V) (200mV/div) Transient Response Waveforms TIME, t (20μs /div) Transient Response to Dynamic Load Change from 0% to 50% to 0%. 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 ON/OFF VOLTAGE OUTPUT VOLTAGE VON/OFF (V) (5V/div) VO (V) (500mV/div) Start-up Using On/Off Voltage (Io = Io,max), Vo=0.69V TIME, t (1 ms/div) ON/OFF VOLTAGE OUTPUT VOLTAGE VO (V) (1V/div) VON/OFF (V) (2V/div) Start-up Using On/Off Voltage (Io = Io,max), Vo=1.8V TIME, t (1 ms/div) Start-up Using On/Off Voltage (Io = Io,max), Vo=3.3V ON/OFF VOLTAGE OUTPUT VOLTAGE VO (V) (500mV/div) VON/OFF (V) (5V/div) TIME, t (1 ms/div) Start-up Using On/Off Voltage (Io = Io,max), Vo=1.2V ON/OFF VOLTAGE OUTPUT VOLTAGE VO (V) (1V/div) VON/OFF (V) (5V/div) TIME, t (2 ms/div) TIME, t (1 ms/div) Start-up Using On/Off Voltage (Io = Io,max), Vo=2.5V ON/OFF VOLTAGE OUTPUT VOLTAGE VO (V) (2V/div) VON/OFF (V) (5V/div) ON/OFF VOLTAGE OUTPUT VOLTAGE VO (V) (200mV/div) VON/OFF (V) (5V/div) Startup Time TIME, t (1 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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 OUTPUT VOLTAGE VO (V) (500mV/div) OUTPUT VOLTAGE VO (V) (1V/div) TIME, t (2ms/div) TIME, t (2ms/div) Start-up Using Input Voltage (VIN = 12V, Io = Io,max), Vo=2.5V OUTPUT VOLTAGE VO (V) (2V/div) OUTPUT VOLTAGE VO (V) (1V/div) Start-up Using Input Voltage (VIN = 12V, Io = Io,max ), Vo=1.8V INPUT VOLTAGE VIN (V) (5V/div) TIME, t (2ms/div) Start-up Using Input Voltage (VIN = 12V, Io = Io,max ), Vo=1.2V INPUT VOLTAGE VIN (V) (5V/div) INPUT VOLTAGE VIN (V) (5V/div) OUTPUT VOLTAGE VO (V) (500mV/div) Start-up Using Input Voltage (VIN = 12V, Io = Io,max), Vo=0.69V INPUT VOLTAGE VIN (V) (5V/div) TIME, t (2ms/div) TIME, t (2ms/div) Start-up Using Input Voltage (VIN = 12V, Io = Io,max ), Vo=3.3V INPUT VOLTAGE VIN (V) (5V/div) INPUT VOLTAGE VIN (V) (5V/div) OUTPUT VOLTAGE VO (V) (200mV/div) Startup Time (continued) TIME, t (2ms/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 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Test Configurations Input Reflected Ripple Current Test Setup. CURRENT PROBE TO OSCILLOSCOPE LTEST VIN(+) BATTERY 1μH CIN CS 1000μF Electrolytic 2x100μF Tantalum E.S.R.<0.1Ω @ 20°C 100kHz COM NOTE: Measure input reflected ripple current with a simulated source inductance (LTEST) of 1μH. Capacitor CS offsets possible 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 measurements to be taken at the module terminals, as shown above. If sockets are used then Kelvin connections are required at the module terminals to avoid measurement errors due to socket contact resistance. Output Voltage and Efficiency Test Setup Rdistribution Rcontact Rcontact VIN(+) RLOAD VO VIN Rdistribution Rcontact Rcontact COM Rdistribution VO Rdistribution COM NOTE: All voltage measurements to be taken at the module terminals, as shown above. If sockets are used then Kelvin connections are required at the module terminals to avoid measurement errors due to socket contact resistance. VO. IO Efficiency η = 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, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Input Filtering The SLIN-20E1Ax should be connected to a low ac-impedance source. A highly inductive source can affect the stability of the module. 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, low-ESR polymer and ceramic capacitors are recommended at the input of the module. To minimize input voltage ripple, ceramic capacitors are recommended at the input of the module. Below figure shows the input ripple voltage for various output voltages at 20A of load current with 2x22 µF or 3x22 µF ceramic capacitors and an input of 12V. 300 2x22uF 250 3x22 uF 200 150 100 50 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Note: Input ripple voltage for various output voltages with 2x22 µF or 3x22 µF ceramic capacitors at the input (20A load). Input voltage is 12V. Output Filtering The SLIN-20E1Ax 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. The figure on the next page provides output ripple information for different external capacitance values at various Vo and for a full load current of 20A. 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 LoopTM feature described later in this data sheet. 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, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Output Filtering (continued) 40 1x10uF External Cap 1x47uF External Cap 2x47uF External Cap 4x47uF External Cap Ripple (mVp-p) 30 20 10 0 0.5 1.5 2.5 3.5 Output Voltage (Volts) 4.5 5.5 Note: Output ripple voltage for various output voltages with external 1x10 µF, 1x47 µF, 2x47 µF or 4x47 µF ceramic capacitors at the output (20A 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, CSA C22.2 No. 60950-1-03, and VDE 0850:2001-12 (EN60950-1) Licensed. 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 20A in the positive input lead. 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, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Remote On/Off Parameter Signal Low (Unit On) Signal High (Unit Off) Signal Low (Unit Off) Signal High (Unit On) Min 0 Typ - Max 1 Unit V 2.0 - Vin,max V - - 3.5 V Vin-1 - Vin,max V Active Low Active High Notes The remote on/off pin open, Unit off. The remote on/off pin open, Unit on. The SLIN-20E1Ax 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, 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, the module turns OFF during logic High and ON during logic Low. The On/Off signal is 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 below. When the external transistor Q1 is in the OFF state, the internal PWM Enable signal is pulled high through an internal 24.9kΩ resistor and the external pullup resistor and the module is ON. When transistor Q1 is turned ON, the On/Off pin is pulled low and the module is OFF. A suggested value for Rpullup is 20kΩ. MODULE VIN+ Rpullup 24.9K 22K I ON/OFF ON/OFF PWM Enable Q2 23K + VON/OFF Q1 GND Q3 22K 12.1K 22K _ Circuit configuration for using positive On/Off logic For negative logic On/Off modules, the circuit configuration is shown below. The On/Off pin should be pulled high with an external pull-up resistor (suggested value for the 4.5V to 14V input range is 20Kohms). When transistor Q1 is in the OFF state, the On/Off pin is pulled high, internal transistor Q2 is turned ON and the module is OFF. To turn the module ON, Q1 is turned ON pulling the On/Off pin low, turning transistor Q2 OFF resulting in the PWM Enable pin going high and the module turning ON. VIN+ MODULE Rpullup1 24.9K PWM Enable I ON/OFF ON/OFF + VON/OFF 22K Q1 GND 23K Q2 12.1K _ Circuit configuration for using negative On/Off logic Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 14 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Over Current 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. 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 135°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-20E1Ax can be programmed to any voltage from 0.69dc to 5.5Vdc by connecting a resistor between the Trim and 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 below figure. The Upper Limit curve shows that for output voltages of 0.9V and lower, the input voltage must be lower than the maximum of 14V. The Lower Limit curve shows that for output voltages of 3.3V and higher, the input voltage needs to be larger than the minimum of 4.5V. 16 Input Voltage (v) 14 12 Upper Limit 10 8 6 4 Lower Limit 2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 Output Voltage (V) Output Voltage vs. Input Voltage Set Point Area plot showing limits where the output voltage can be set for different input voltages. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 15 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Output Trim Equations Without an external resistor between Trim and GND pins, the output of the module will be 0.69Vdc. To calculate the value of the trim resistor, Rtrim, for a desired output voltage, use the following equation: ⎡ ⎤ 6.9 Rtrim = ⎢ ⎥ kΩ ( ) Vo − 0 . 69 ⎣ ⎦ Rtrim is the external resistor in kΩ Vo is the desired output voltage. 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 2.5 3.3 5.0 Rtrim (KΩ) 690 22.26 13.53 8.519 6.216 3.812 2.644 1.601 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 SLIN-20E1Ax power modules have a Remote Sense feature to minimize the effects of distribution losses by regulating the voltage between the S+ and S– pins. The voltage between the S– and GND pins of the module must not drop below –0.2V. If Remote Sense is being used, the voltage between S+ and S– cannot be more than 0.5V larger than the voltage between VOUT and GND. Note that the output voltage of the module cannot exceed the specified maximum value. When the Remote Sense feature is not being used, connect the S+ pin to the VOUT pin and the S– pin to the GND pin. V IN(+) VO (+) VS+ ON/OFF LOAD TRIM R tri m GND Circuit configuration for programming output voltage using an external resistor Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 16 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Startup into Pre-biased Output The SLIN-20E1Ax 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. Voltage Margining Output voltage margining can be implemented in the SLIN-20E1Ax 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. Vo Rmargin-down MODULE Q2 Trim Rmargin-up Rtrim Q1 GND Circuit Configuration for margining Output voltage Monotonic Start-up and Shutdown The SLIN-20E1Ax modules have monotonic start-up and shutdown behavior for any combination of rated input voltage, output current and operating temperature range. Output Voltage Sequencing The SLIN-20E1Ax 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, either tie the SEQ pin to VIN or 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 volt 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 for negative logic modules or tied to VIN for positive logic modules) so that the module is ON by default. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 17 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Output Voltage Sequencing (continued) After applying input voltage to the module, a minimum 10msec delay is required before applying voltage on the SEQ pin. During this time, a voltage of 50mV (± 20 mV) is maintained on the SEQ pin. This can be done by applying the sequencing voltage through a resistor R1 connected in series with the SEQ pin. This delay gives the module enough time to complete its internal power-up soft-start cycle. During the delay time, the SEQ pin should be held close to ground (nominally 50mV ± 20 mV). This is required to keep the internal opamp out of saturation thus preventing output overshoot during the start of the sequencing ramp. By selecting resistor R1 according to the following equation: R1 = 24950 V IN − 0.05 ohms The voltage at the sequencing pin will be 50mV when the sequencing signal is at zero. MODULE VIN+ 499K + OUT R1 SEQ 10K - GND Circuit showing connection of the sequencing signal to the SEQ pin 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 bases 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 representative for additional information. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 18 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Power Good The SLIN-20E1Ax modules provide 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 over temperature, over current or loss of regulation occurs that would result in the output voltage going ±10% outside the set point value. The PGOOD terminal should be connected through a pull-up resistor (suggested value 100KΩ) to a source of 5VDC or less. Synchronization The SLIN-20E1Ax modules can be synchronized using an external signal. Details of the SYNC signal are provided in the Electrical Specifications table. If the synchronization function is not being used, leave the SYNC pin floating. Tunable LoopTM The SLIN-20E1Ax modules have a new feature that optimizes transient response of the module called Tunable LoopTM. 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. The Tunable LoopTM 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, as shown below. This R-C allows the user to externally adjust the voltage loop feedback compensation of the module. VOUT SENSE RTUNE MODULE CO CTUNE TRIM GND RTrim 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 below Tables 2 and 3. Table 2 shows the recommended values of RTUNE and CTUNE for different values of ceramic output capacitors up to 470uF that might be needed for an application to meet output ripple and noise requirements. Selecting RTUNE 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 10A to 20A step change (50% of full load), with an input voltage of 12V. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 19 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Tunable LoopTM (continued) Table 2.General recommended values of RTUNE and CTUNE for Vin=12V and various external ceramic capacitor combinations. Co RTUNE CTUNE 1x47μF 240 1500pF 2x47μF 240 2700pF 4x47μF 240 5600pF 10x47μF 20x47μF 150 150 12nF 15nF Table 3.Recommended values of RTUNE and CTUNE to obtain transient deviation of ≤2% of Vout for a 10A step load with Vin=12V. Vo Co RTUNE CTUNE ΔV 5V 3.3V 5x47μF + 330μF 6x47μF Polymer 220 220 5600pF 7500pF 99mV 66mV 2.5V 2x330μF Polymer 200 18nF 50mV 1.8V 1.2V 6x47μF + 2x 330μF 6x47μF + 4x330μF Polymer Polymer 150 150 33nF 120nF 36mV 24mV 0.69V 12x330μF Polymer 150 120nF 12mV 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 Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 20 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Thermal Considerations (continued) The preferred airflow direction and the thermal reference points, Tref, used in the specifications are also shown below. For reliable operation the temperatures at these points should not exceed 125oC. 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). Example Application Circuit Requirements: Vin: Vout: Iout: ΔVout: Vin, ripple 12V 1.8V 15A max., worst case load transient is from 10A to 15A 1.5% of Vout (36mV) for worst case load transient 1.5% of Vin (180mV, p-p) Vin+ Vout+ VOUT S+ VIN RTUNE + CI2 MODULE CI1 CTUNE Q1 ON/OFF GND CI1 CI2 CO1 CO2 CTune RTune RTrim CO1 + CO2 TRIM S- RTrim 2 x 22μF/16V ceramic capacitor (e.g. Murata GRM32ER61C226KE20) 200μF/16V bulk electrolytic 5 x 47μF/6.3V ceramic capacitor (e.g. Murata GRM31CR60J476ME19) 2 x 330μF/6.3V Polymer (e.g. Sanyo, Poscap) 22nF ceramic capacitor (can be 1206, 0805 or 0603 size) 150 ohms SMT resistor (can be 1206, 0805 or 0603 size) 6.19kΩ 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 21 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Mechanical Outline Top View Side View Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 22 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Mechanical Outline (continued) Recommended Pad Layout PIN FUNCTION 1 ON/OFF 2 VIN 3 SEQ 4 GND 5 VOUT 6 TRIM 7 S+ 8 S- 9 PGOOD 10 SYNC 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.) Note: This module is recommended and compatible with Pb-Free Reflow Soldering and must be soldered using a reflow profile with a peak temperature of no more than 260 ºC for less than 5 seconds. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 23 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Packaging Details The SLIN-20E1Ax modules are supplied in tape & reel as standard. Modules are shipped in quantities of 250 modules per reel. 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”) 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 24 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 Surface Mount Information Pick and Place The SLIN-20E1Ax 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. Nozzle Recommendations The 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. Lead Free Soldering The SLIN-20E1Ax 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. The suggested Pb-free solder paste is Sn/Ag/Cu (SAC). The recommended linear reflow profile using Sn/Ag/Cu solder is shown in the figure below. Soldering outside of the recommended profile requires testing to verify results and performance. MSL Rating The SLIN-20E1Ax 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. 300 Per J-STD-020 Rev. C Peak Temp 260°C Reflow Temp (°C) 250 200 * Min. Time Above 235°C 15 Seconds Cooling Zone 150 Heating Zone 1°C/Second *Time Above 217°C 60 Seconds 100 50 0 Reflow Time (Seconds) Recommended linear reflow profile using Sn/Ag/Cu solder. Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com 25 NON-ISOLATED DC/DC CONVERTERS 4.5 Vdc - 14 Vdc Input, 0.69 Vdc - 5.5 Vdc /20 A Outputs Bel Power, Inc. , a subsidiary of Bel Fuse, Inc. October 8, 2009 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. Revision History Date Revision Changes Detail 2009-6-10 A First release 2009-6-25 B Section “Surface Mount Information” added. Approval T. Bubriski TM T. Bubriski 2009-9-1 C Tunable Loop logo added. T. Bubriski 2009-10-8 D Updated Startup Time waveforms on page 10. 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. ©2009 Bel Fuse Inc. Specifications subject to change without notice.10/08/09 26 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