78250J Series www.murata-ps.com MAX250/MAX251 Compatible Converter SM Transformers CHARACTERISTICS 78250JC Parameter Conditions Min. Typ. Max. Units Primary Inductance, L 10kHz, 100mV 1.0 2.0 2.5 mH P Leakage Inductance, L 100kHz, 100mV 0.6 3.0 H L Interwinding Capacitance, C 100kHz, 100mV 48 90 pF WW Primary D.C. Resistance, R <0.1VDC 0.7 2.0 DC Volt-time Product, Et Pins1/2 or 2/3 50 Vs Turns Ratio 1:1 FEATURES CHARACTERISTICS 78250JVC n J-STD-020D reflow Parameter Conditions Min. Typ. Max. Units n RoHS compliant Primary Inductance, L 10kHz, 100mV 1.0 2.0 2.5 mH P Leakage Inductance, L 100kHz, 100mV 35 40 H n Maxim MAX250/MAX251 compatible L Interwinding Capacitance, C 100kHz, 100mV 4 10 pF WW n Isolation to 4kVrms Primary D.C. Resistance, R <0.1VDC 0.9 1.8 DC n Industry-standard pinout Volt-time Product, Et Pins1/2 or 2/3 50 Vs Turns Ratio 1:1 n Surface mount option n UL 94 V-0 package materials ORDER CODE DETAILS Order Code Package Type Packaging Type Quantity n Low profile 78250JC / 78250JVC 6 Pin SM Tube 50 n Toroidal construction 78250JC-R / 78250JVC-R 6 Pin SM Tape & Reel 500 n Industrial temperature range ABSOLUTE MAXIMUM RATINGS Operating free air temperature range -40C to 85C DESCRIPTION Storage temperature range -50C to 125C Lead temperature 1.5mm from case for 10 seconds 300C The 78250 series of converter transformers Peak current, I 300mA are specifically designed for use with Maxim PK Isolation voltage 78250(J)C (flash tested for 1 second) 1.5kVrms chipsets to provide isolated RS232 interfaces. Isolation voltage 78250V(J)C (flash tested for 1 second) 4.0kVrms Carefully controlled turns ratios ensure consistent performance whilst a toroidal construction All specifications typical at T =25C A minimises EMI. TECHNICAL NOTES For through hole versions see 78250 datasheet. ISOLATION VOLTAGE REPEATED HIGH-VOLTAGE ISOLATION TESTING Hi Pot Test, Flash Tested, Withstand Voltage, Proof Voltage, It is well known that repeated high-voltage isolation Dielectric Withstand Voltage & Isolation Test Voltage are all testing of a barrier component can actually degrade terms that relate to the same thing, a test voltage, applied for a isolation capability, to a lesser or greater degree specified time, across a component designed to provide electri - depending on materials, construction and environ- cal isolation, to verify the integrity of that isolation. ment. This series has toroidal isolation transformers, with no additional insulation between primary and All products in this series are 100% production tested at secondary windings of enameled wire. While parts their stated isolation voltage. can be expected to withstand several times the stated A question commonly asked is, What is the continuous volt- test voltage, the isolation capability does depend on age that can be applied across the part in normal operation the wire insulation. Any material, including this enamel For a part holding no specific agency approvals both input (typically polyurethane) is susceptible to eventual and output should normally be maintained within SELV limits chemical degradation when subject to very high ap- i.e. less than 42.4V peak, or 60VDC. The isolation test volt- plied voltages thus implying that the number of tests age represents a measure of immunity to transient voltages should be strictly limited. We therefore strongly advise and the part should never be used as an element of a safety against repeated high voltage isolation testing, but if it isolation system. The part could be expected to function cor- is absolutely required, that the voltage be reduced by rectly with several hundred volts offset applied continuously 20% from specified test voltage. across the isolation barrier but then the circuitry on both This consideration equally applies to agency recog- sides of the barrier must be regarded as operating at an nized parts rated for better than functional isolation unsafe voltage and further isolation/insulation systems must where the wire enamel insulation is always supple- form a barrier between these circuits and any user-accessi- mented by a further insulation system of physical ble circuitry according to safety standard requirements. For full details go to spacing or barriers. www.murata-ps.com/rohs www.murata-ps.com/support KMP 78250JC A03 Page 1 of 378250J Series MAX250/MAX251 Compatible Converter SM Transformers PACKAGE SPECIFICATIONS MECHANICAL DIMENSIONS 0.5 (12.70) 0.375 (9.52) Max. Primary Secondary 1 6 0.354 2 5* (9.0) Max. 78250JC 3 4 XYYWW 0.25 (6.35) 0.012 (0.30) 0.025 (0.63) 0.008 (0.20) 0.035 (0.90) 0.021 (0.53) 0.1 (2.54) Unless otherwise stated all dimensions in inches (mm) 0.01 (0.25). All pins on a 0.1 (2.54) pitch and within 0.01 (0.25) of true position. * Pin 5 is connected to secondary center tap. Package Weight 1.0g TYP. RECOMMENDED FOOTPRINT DETAILS 0.10 (2.54) 0.06 (1.60) 0.10 (2.54) 0.10 (2.54) +0.006 (0.15) 0.05 (1.20) -0.000 (0.00) 0.04 (1.00) 0.45 (11.50) Unless otherwise stated all dimensions in inches (mm) 0.01 (0.25). All pins on a 0.1 (2.54) pitch and within 0.01 (0.25) of true position. 1 TUBE OUTLINE DIMENSIONS SOLDERING INFORMATION 0.43 Pin finish Matte tin (10.95) Max. peak reflow temperature 245C Unless otherwise stated all 2 Moisture sensitivity level 1 0.16 (4.00) dimensions in inches (mm) 0.01 (0.25). Max. time above liquidous (217C) 100s 0.0230.005 0.51 Tube length: 18.30.08 (4652). 1 For further information, please visit www.murata-ps.com/rohs (0.600.15) (12.95) 2 Representative samples of the product were subjected to the conditioning described in IPC/JEDEC Tube material: Antistatic coated clear pvc. J-STD-020D and passed electrical testing, package coplanarity and visual inspection which 0.22 (5.50) revealed no external cracks or changes in package body flatness. 0.15 (3.80) 0.62 (15.70) www.murata-ps.com/support KMP 78250JC A03 Page 2 of 3