BPC-Series-AN (4C).qxd 8/9/03 7:59 am Page 3 Resistive Components BPC Series Power Resistors Non-inductive Planar Thick Film Power Resistors • Planar thick film • Low inductance • High frequency operation • Vertical mount • Low board level temperature • 20x rated power surge A subsidiary of TT electronics plc BI Technologies BPC-Series-AN (4C).qxd 8/9/03 7:59 am Page 4 2 BI Technologies offer the BPC series of non-inductive planar thick film power resistors for current limiting, power supply circuits and snubber circuits. Manufactured using 96% Alumina substrates with Ruthenium oxide resistors the BPC series power resistors are capable of withstanding a 20x overload for 8ms and offer excellent performance and high reliability. BPC series power resistors are available in 3, 5, 7.5 and 10 watt power ratings as shown below. Size Power rating Dimensions (length, width, thickness) BPC3 BPC5 BPC7 BPC10 3W 5W 7.5W 10W 27.7 x 10.2 x 2.54mm 27.7 x 12.7 x 2.54mm 27.7 x 19.1 x 2.54mm 27.7 x 25.4 x 2.54mm Range 1Ω to 200kΩ Standard Tolerance % ±10 (optional 1, 2, 5) Operating Temperature Range -55°C to +125°C Operating Voltage Maximum 300 VAC, 500 VDC Temperature Coefficient of Resistance ±100 maximum ppm/°C (± 250 for values below 1ohm) Why Use BI Technologies BPC Series Power Resistors? • Planar Thick Film Cermet Resistor - Very low inductance for high frequency operation. • Large surface area to thickness ratio - maximises power dissipation, minimises hot spots. • 20x Rated power surge capability. • Vertical mounting. Power is dissipated above the circuit board. Enhances board cooling due to natural convection flow. • Low operating temperature at board surface means high temperature solder is not required. • Minimises required board area. Uses only a third board area versus a typical wirewound resistor. 1. Inrush current suppression The BPC may be used to limit inrush current when a power supply is switched on. Figure 1 shows a typical PFC circuit in which two BPC10 resistors in series function in an inrush current suppression circuit which operates principally at switch-on. BPC010 BPC010 5Ω 5Ω Ct HM31 Vo 400Vdc L1 HM00 AC Line EMI filter Ct HM31 Load Co gate driver PFC PWM Figure 1: A typical PFC Circuit showing two BPC resistors for current inrush suppression BPC-Series-AN (4C).qxd 8/9/03 8:00 am Page 5 3 2. Snubber circuits and Start-up Circuits The BPC may be used in series with a capacitor in a snubber circuit to filter spikes in the rising and falling edges of square waves. EMI filter BP3 500Ω R2 BPC5 50kΩ R1 In Figure 2 BPC3 500Ω is used. Figure 2 also includes a start-up circuit that provides 18 Volts to the PWM while the power supply is turning on. In this case a 50kΩ, BPC5 is utilised. to output circuitry PWM 18V 47µF Figure 2: Circuit showing BPC Resistors in Start-up (R1) and Snubber (R2) Applications 3. Inrush current limiting This resistor limits the amount of current allowed to surge into the system at turnon. Power resistors in this circuit must be able to withstand a 20x nominal surge for 8msec. This is typically a 15Ω, 7-10 Watt, 10% resistor. A typical location of this resistor is shown in Figure 3. This resistor carries the main current load. AC input EMI/RFI filter * other power resistors inrush power resistor Figure 3: Circuit showing a BPC Resistor in an Inrush Application 4. Other Snubber Circuits In these applications the power resistor bleeds current of the magnetics to prevent inductive spikes. This resistor will experience voltage spikes at 2x the switchmode switching frequency. This is typically a 500Ω to 1kΩ, 3W to 5W, 2% to 5% resistor. Circuit configurations are found in Figure 4. 1000pF 1000Vdc ceramic L101 FBL-00-103 1kΩ 2% 3W FBL-00-103 FBL-00-256 Snubber Circuit 1 Figure 4: Snubber circuits found in power supplies 240pF 20% 1kV ceramic Snubber Circuit 2 BPC-Series-AN (4C).qxd 8/9/03 8:00 am Page 6 Resistive Components 5. Biasing (Current conditioning) These resistors do not experience surges or spikes. This is a steady state application. In these applications the resistor values vary considerably from 200Ω to 20kΩ, 3W to 5W, 2% to 5%. An example is shown in Figure 5. Biasing resistor to dc section Figure 5: Circuit from a high-current power supply which uses a BPC resistor for Biasing 6. Preloading (1) This resistor experiences a steady state condition. The typical resistor is 3Ω to 1kΩ with 10% tolerance. The preloading is usually a function of the circuit. An example is shown in Figure 6. 10kΩ 0.1Ω 4.7µF 180Ω 470pF 1000V ceramic from switching circuitry 1500µF 35V 650Ω 3W output preload resistor power resistor Figure 6: Part of proprietary power supply showing two power resistors 7. Current Limiting 0.01µF(5kV) BPC resistors have uses as current limiters in high-voltage power supplies. An example of a high voltage power supply, which is used to drive a laser, is shown in Figure 7 and the BPC resistor is highlighted. 1800pF 47k 5W 1800pF BPC5 high voltage diodes laser Vsw Vin switching Vfb regulator Figure 7: Laser power supply showing a BPC5 for current limiting 4 BPC-Series-AN (4C).qxd 8/9/03 7:58 am Page 1 Resistive Components 8. Preloading (2) Another example of preloading is in a Battery Charger circuit as shown in Figure 8 where a resistor is used as a dummy load to prevent overcharging the battery. Si9405 1M 6.8V 3.65M 7.5Ω 10W BPC10 8M 1M load 1A solar array 340k TIP121 12V 5Ahr 1M VN2222 1.2V Figure 8: Shunt battery charger which uses a BPC10 Inrush Application Model BPC Vertical mounting Enhances board cooling due to natural convection airflow Planar, Thick Film Cermet Resistor Time (milliseconds) Non inductive 20x Nominal Power Rating Automated laser trimming Large surface Maximises power dissipation and minimises hot spot Accurate and stable resistance values Power Leads soldered on both sides Built-in stand off Low operating temperature At board surface high temperature solder not required Vertical mounting Minimises board area 0 Inrush Application 8 5 BPC-Series-AN (4C).qxd 6 8/9/03 7:59 am Page 2 Resistive Components BI Technologies - SMT BI Technologies - ECD BI Technologies - MCD Company Profile Company Profile Company Profile BI Technologies, SMT Division is a World Class manufacturer of thick film Passive Components. The company was established in 1958 in Glenrothes, Scotland. BI Technologies have earned a great reputation as a high quality, high volume, cost effective and responsive supplier of thick film passive components for telecommunications, computer, automotive, medical and industrial applications. BI Technologies has been an innovator and leader in electronic components for more than 50 years manufacturing products for communication, computer, industrial and automotive applications. BI Technologies, Magnetic Component Division, headquartered in Fullerton, California, with a manufacturing base in Kuantan, Malaysia, is a world leader in miniature surface mount high power inductors. The magnetic material and manufacturing expertise of various inductors, choke coils, transformers and assemblies has expanded the customer and market base into automotive, medical, computer, data communication and industrial in addition to other specialized magnetic assembly applications. Product Range Product Range Product Range • Packaged SIL, DIL and Surface Mount Resistor Networks • Chip Resistor Arrays • Chip Resistor - Capacitor Arrays • Planar Power Resistors • Surge Resistors • Thick Film Substrates • Custom Thick Film products • High Voltage Resistors and Networks • Trimming and Precision Potentiometers • Position Sensors • Chip Resistor Arrays • Resistor Networks • Integrated Passive Networks • Inductors • Transformers • Turns Counting Dials • Hybrid Microelectronics and Custom Integration Products • Transformers both surface mount and through hole • Surface Mount high powered inductors • Toroidal inductors (through hole and surface mount) • High power specialty laminate transformers • Data communication modules, filters, and transformers for ethernet and DSL • Common mode filters and chokes • Planar transformer solutions BI Technologies serves a global customer base with manufacturing locations in the United States, Mexico, Scotland, Japan, China and Malaysia. BI Technologies SMT BI Technologies ECD BI Technologies Pte Ltd TT electronics GmbH Telford Road, Glenrothes Fife KY7 4NX, Scotland, UK 4200 Bonita Place Fullerton, CA 92835, USA Max-Lehner-Strasse 31 85354 Freising, GERMANY Tel: +44 1592 662200 Fax: +44 1592 662299 [email protected] Tel: +714 447 2300 Fax: +714 447 2400 [email protected] 514 Chai Chee Lane, #02-01 Bedok Industrial Estate 469029 SINGAPORE TT electronics SA TT electronics S.r.l. BI Technologies Japan Ltd Sales/Technical Support Centre 17 Rue du Kefir, Senia 418 94567 Orly, FRANCE Via Arese 12 20159 Milan, ITALY Tel: +33 1 45 12 3880 Fax: +33 1 45 12 3879 Tel: +39 2 688 8951 Fax: +39 2 689 6995 Kakumaru Building 4/F 1-10 Toyo 7 Chome Koto-ku Tokyo 135, JAPAN Flat 1104, 11/F, Block 1 News Building, No. 2 Shennan Middle Road, Futian District, Shenzhen, CHINA 518027 Tel: +81 3 3615 1811 Fax: +81 3 3647 2443 Tel: +86 755 8209 0230 / 8209 0295 Fax: +86 755 8209 0267 Tel: +65 445 5166 Fax: +65 445 1983 Tel: +49 8161 4908-0 Fax: +49 8161 4908-99 www.bitechnologies.com · www.ttelectronics.com · www.bitechnologies.co.jp Authorised Representative BI Technologies General Note: BI Technologies reserves the right to make changes in product specification without notice or liability. All information is subject to BI Technologies’ own data and is considered accurate at time of going to print. © BI Technolgies 2003 A subsidiary of TT electronics plc Issue B 09/03