78250J Series www.murata-ps.com MAX250/MAX251 Compatible Converter SM Transformers CHARACTERISTICS 78250JC FEATURES n J-STD-020D reflow n RoHS compliant n Maxim MAX250/MAX251 compatible n Isolation to 4kVrms n Industry-standard pinout n Surface mount option n UL 94 V-0 package materials n Low profile n Toroidal construction n Industrial temperature range DESCRIPTION The 78250 series of converter transformers are specifically designed for use with Maxim chipsets to provide isolated RS232 interfaces. Carefully controlled turns ratios ensure consistent performance whilst a toroidal construction minimises EMI. For through hole versions see 78250 datasheet. Parameter Conditions Min. Typ. Max. Units Primary Inductance, LP Leakage Inductance, LL Interwinding Capacitance, CWW Primary D.C. Resistance, RDC Volt-time Product, Et Turns Ratio 10kHz, 100mV 100kHz, 100mV 100kHz, 100mV <0.1VDC Pins1/2 or 2/3 1.0 2.0 0.6 48 0.7 2.5 3.0 90 2.0 mH μH pF CHARACTERISTICS 78250JVC Parameter Conditions Min. Typ. Max. Units Primary Inductance, LP Leakage Inductance, LL Interwinding Capacitance, CWW Primary D.C. Resistance, RDC Volt-time Product, Et Turns Ratio 10kHz, 100mV 100kHz, 100mV 100kHz, 100mV <0.1VDC Pins1/2 or 2/3 1.0 2.0 35 4 0.9 2.5 40 10 1.8 mH μH pF Ω 50 Vμs 1:1 ORDER CODE DETAILS Order Code 78250JC / 78250JVC 78250JC-R / 78250JVC-R Package Type 6 Pin SM 6 Pin SM Packaging Type Tube Tape & Reel Quantity 50 500 ABSOLUTE MAXIMUM RATINGS Operating free air temperature range Storage temperature range Lead temperature 1.5mm from case for 10 seconds Peak current, IPK Isolation voltage 78250(J)C (flash tested for 1 second) Isolation voltage 78250V(J)C (flash tested for 1 second) -40°C to 85°C -50°C to 125°C 300°C 300mA 1.5kVrms 4.0kVrms All specifications typical at TA=25°C TECHNICAL NOTES ISOLATION VOLTAGE REPEATED HIGH-VOLTAGE ISOLATION TESTING ‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Voltage’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ are all terms that relate to the same thing, a test voltage, applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation. It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials, construction and environment. This series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enameled wire. While parts can be expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically polyurethane) is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We therefore strongly advise against repeated high voltage isolation testing, but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage. A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?” For full details go to www.murata-ps.com/rohs Vμs 1:1 All products in this series are 100% production tested at their stated isolation voltage. Ω 50 For a part holding no specific agency approvals both input and output should normally be maintained within SELV limits i.e. less than 42.4V peak, or 60VDC. The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system. The part could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on both sides of the barrier must be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry according to safety standard requirements. This consideration equally applies to agency recognized parts rated for better than functional isolation where the wire enamel insulation is always supplemented by a further insulation system of physical spacing or barriers. www.murata-ps.com/support KMP_78250JC_A03 Page 1 of 3 78250J Series MAX250/MAX251 Compatible Converter SM Transformers PACKAGE SPECIFICATIONS MECHANICAL DIMENSIONS 0.5 (12.70) 0.375 (9.52) Max. Primary 1 0.354 (9.0) Max. 78250JC XYYWW Secondary 6 2 5* 3 4 0.25 (6.35) 0.012 (0.30) 0.008 (0.20) 0.025 (0.63) 0.021 (0.53) 0.035 (0.90) 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) Ø0.05 (1.20) +0.006 (0.15) -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. TUBE OUTLINE DIMENSIONS SOLDERING INFORMATION1 0.43 (10.95) Unless otherwise stated all dimensions in inches (mm) ±0.01 (0.25). 0.16 (4.00) 0.023±0.005 (0.60±0.15) 0.51 (12.95) Tube length: 18.3±0.08 (465±2). Tube material: Antistatic coated clear pvc. 0.22 (5.50) Pin finish Max. peak reflow temperature Moisture sensitivity level2 Max. time above liquidous (217°C) Matte tin 245°C 1 100s 1 For further information, please visit www.murata-ps.com/rohs 2 Representative samples of the product were subjected to the conditioning described in IPC/JEDEC J-STD-020D and passed electrical testing, package coplanarity and visual inspection which 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 78250J Series MAX250/MAX251 Compatible Converter SM Transformers TAPE & REEL SPECIFICATIONS REEL OUTLINE DIMENSIONS 2.36 (60) Min. Ø15.039 (382) Max. 0.94-1.08 (23.9-27.4)* Ø 0.53 (13.50) 0.50 (12.80) Leader section 15.7 (400) Min. 3.9 (100) Min. 0.059 (1.50) Min. 1.20 (30.4) Max. Goods enclosure section 0.96 (24.4) 1.04 (26.4) Trailer section 6.3 (160) Min. Unless otherwise stated all dimensions in inches (mm) ±0.01(0.25). Ø 0.80 (20.20) Min. * Includes flange distortion at outer edge. Measured at hub. TAPE OUTLINE DIMENSIONS 0.453 (11.50) 0.157 (4.00) +0.004 +0.10 0.059 -0.000 (1.50 -0.00 ) 0.079 (2.00) XYYWW 78250JC 0.945 +0.012 (24.00 +0.30 -0.10 ) -0.004 0.069 (1.75) Cover tape 0.369 (9.37) 0.472 (12.00) 0.024 (0.60) Max. Direction of unreeling 0.283 (7.20) Unless otherwise stated all dimensions in inches (mm) ±0.01(0.25). Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. ISO 9001 and 14001 REGISTERED Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. © 2011 Murata Power Solutions, Inc. www.murata-ps.com/support KMP_78250JC_A03 Page 3 of 3