SMT PLANAR TRANSFORMER AND PLANAR INDUCTOR For use with Linear Technologys PLANAR TRANSFORMER PA0191 LT1681 and LTC1698 Power Rating: 60-100W Height: 8.3 mm Max Footprint: 27.7 mm x 21.8 mm Max PLANAR INDUCTOR P1977 Energy Storage: 420 J (2.1 H/20A) Height: 8.3 mm Max Footprint: 21.7 mm x 20.3 mm Max Electrical Specifications 25C Operating Temperature -40C to 125C Primary Primary Leakage DCR Part Power Turns Ratio Secondary Inductance Inductance Primary Primary Aux. Secondary 1 Number Rating (with 7T Pri. Aux.) Isolation (H MIN) (H MAX) (m MAX) (m MAX) (m MAX) PA0191 60-100 W 9:2 1500 Vdc Basic 100 1.5 85 800 2.5 Electrical Specifications 25C Operating Temperature -40C to 125C 3 2 DCR Saturation Current Inductance Inductance Heating Part Irated 4 (m ) (A) Irated 0 A Current DC Number (A ) DC (A) (H 5%) (H 5%) TYP MAX 25C 125C P1977 2.1 20 1.00 1.25 2.1 27.0 22.5 31 Mechanicals Schematics PA0191 % % % &* () () () &% () % * & & & % & %* & () % () % % & & P1977 * & & PA0191 P1977 Weight ..................11.0 grams ..................10.8 grams () () Tape & Reel...............150/reel.......................150/reel % % Tray.............................55/tray.........................48/tray && && Inches Dimensions: mm .010 % Unless otherwise specified, all tolerances are 0,25 US 619 674 8100 UK 44 1483 401 700 France 33 3 84 35 04 04 Singapore 65 287 8998 Taiwan 886 2 2698 0228 Hong Kong 852 2788 6588 SMT PLANAR TRANSFORMER AND INDUCTOR For use with Linear Technologys LT1681 and LTC1698 Notes from Tables For PA0191: Basic Insulated Planar Transformer 1.To determine if the transformer is suitable for your application it the specified ambient environment and applying a short duration is necessary to ensure that the temperature rise of the compo- pulse current (to eliminate self-heating effects) to the compo- nent (ambient plus temp. rise) does not exceed its operating nent. temperature. To determine the temperature rise of the compo- 4.The heating current is the dc current which causes the tempera- nent it is necessary to calculate the total power losses (copper ture of the part to increase by approximately 40C. This current and core) in the application. is determined by mounting the component on a PCB with a .25 Total Copper Losses wide (2 ounce equivalent copper traces) and applying the CopperTotal (W) = sum of the losses in each winding current to the device for 30 minutes. The losses in each winding can be calculated by: 5.In high volt*time applications additional heating in the compo- 2 nent can occur due to core losses in the inductor which may CopperWindingX (W) = .001 * DCR(m ) * (Irms ) neccessitate derating the current in order to limit the tempera- Core Losses ture rise of the component. In order to determine the approxi- To calculate the core loss, use the following formula: mate total losses (or temperature rise) for a given application 1.7 2.5 CoreLoss (W) = 2.5E-8 * (Freq kHz) * ( B/2000) both copper and core losses should be taken into account. where: Total Copper Losses B/2000 = 1.01 * (Voltage Min * Dutycycle Max/Freq kHz) 2 CopperTotal (W) = .001* DCR(m ) * (Irms ) Temperature Rise where: TempRise (C) = .603 * CopperTotal (W) * (50.6 * CoreLoss 2 2 .5 Irms = (IDC + ( I/2) ) (W)/CopperTotal (W) + 88.1) Core Losses For P1977: Planar Inductor To calculate the core loss, use the following formula: 2.The rated current as listed is either the saturation current or the 1.7 2.5 CoreLoss (W) = 2.5E-8 * (Freq kHz) * (.0635 * I) heating current depending on which value is lower. Temperature Rise 3.The saturation current is the current which causes the induc- tance to drop by 10% at the stated ambient temperatures (25C, TempRise (C) = .603 * CopperTotal (W) * (50.6 * CoreLoss 125C). This current is determined by placing the component in (W)/CopperTotal (W) + 88.1) APPLICATION NOTES The PA0191 transformer and P1977 inductor were designed for use with Linear Technology s LT1681 and LTC1698 IC s and are featured in Linear Technology s Design note 261 which details the solution for a low cost, discrete component alternative to telecom power modules. The PA0191 transformer and P1977 inductor were designed for (but not limited to) the following application: Topology Two-switch forward Frequency 230 kHz Pri./Sec. Isolation Basic Insulation (1500 Vdc) Input Voltage 36-72 v telecom input Output Voltage(s) 3.3 v / 20 A output (with an auxilary primary side control winding - 12 v/100 mA) + + For More Information : UNITED STATES UNITED KINGDOM FRANCE SINGAPORE TAIWAN, R.O.C. HONG KONG DISTRIBUTOR (Worldwide) (Northern Europe) (Southern Europe) (Southern Asia) (Northern Asia) (China/Hong Kong) 1 & 2 Huxley Road 12220 World Trade Drive Zone Industrielle 150 Kampong Ampat 3F-4, No. 81, Sec. 1 19/F, China United Plaza The Surrey Research Park San Diego, CA 92128 F-39270 07-01/02 HsinTai Wu Road 1008 Tai Nan West Street Guildford, Surrey GU2 5RE U.S.A. Orgelet KA Centre Hsi-Chih, Taipei Hsien Cheung Sha Wan, Kowloon United Kingdom