78250 Series www.murata-ps.com MAX250/MAX251 Compatible Converter Transformers CHARACTERISTICS 78250C/78250MC Parameter Conditions Min. Typ. Max. Units Primary Inductance, L 10kHz, 100mV 1.0 2.0 2.5 mH P Leakage Inductance, L 100kHz, 100mV 2.0 3.0 μH L Interwinding Capacitance, C 100kHz, 100mV 69 90 pF WW Primary D.C. Resistance, R <0.1VDC 1.0 2.0 Ω DC Volt-time Product, Et Pins1/2 or 2/3 50 Vμs FEATURES CHARACTERISTICS 78250VC/78250MVC (cid:132)(cid:3)RoHS compliant Parameter Conditions Min. Typ. Max. Units Primary Inductance, L 10kHz, 100mV 1.0 2.0 2.5 mH (cid:132)(cid:3)Maxim MAX250/MAX251 compatible P Leakage Inductance, L 100kHz, 100mV 35 40 μH L (cid:132)(cid:3)Isolation to 4kVrms Interwinding Capacitance, C 100kHz, 100mV 9 12 pF WW Primary D.C. Resistance, R <0.1VDC 1.4 1.8 Ω (cid:132)(cid:3)Industry-standard pinout DC Volt-time Product, Et Pins1/2 or 2/3 50 Vμs (cid:132)(cid:3)Surface mount option ORDER CODE DETAILS (cid:132)(cid:3)UL 94 V-0 package materials Order Code Package Type Packaging Type Quantity (cid:132)(cid:3)Low profile 78250C / 78250VC 6 Pin DIL Tube 50 (cid:132)(cid:3)Toroidal construction 78250MC / 78250MVC 6 Pin SM Tube 50 78250MC-R / 78250MVC-R 6 Pin SM Tape & Reel 500 (cid:132)(cid:3)Fully encapsulated (cid:132)(cid:3)Industrial temperature range ABSOLUTE MAXIMUM RATINGS Operating free air temperature range -40°C to 85°C Storage temperature range -50°C to 125°C DESCRIPTION Lead temperature 1.5mm from case for 10 seconds 300°C The 78250 series of converter transformers Peak current, I 300mA PK are specifically designed for use with Maxim Isolation voltage 78250(M)C (flash tested for 1 second) 1.5kVrms chipsets to provide isolated RS232 interfaces. Isolation voltage 78250(M)VC (flash tested for 1 second) 4.0kVrms Carefully controlled turns ratios ensure consistent All specifications typical at T=25°C performance whilst a toroidal construction A TECHNICAL NOTES minimises EMI. ISOLATION VOLTAGE REPEATED HIGH-VOLTAGE ISOLATION TESTING ‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Volt- It is well known that repeated high-voltage isolation Surface-mount parts age’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ testing of a barrier component can actually degrade The surface-mount (M suffix) products are not are all terms that relate to the same thing, a test voltage, isolation capability, to a lesser or greater degree recommended for new designs. For existing designs, applied for a specified time, across a component designed depending on materials, construction and environ- to provide electrical isolation, to verify the integrity of that ment. This series has toroidal isolation transformers, however, Murata Power Solutions will continue to isolation. with no additional insulation between primary and manufacture and fully support these parts. All products in this series are 100% production tested at secondary windings of enameled wire. While parts For recommended alternatives please refer to the their stated isolation voltage. can be expected to withstand several times the 78250J Series datasheet. stated test voltage, the isolation capability does de- A question commonly asked is, “What is the continuous pend on the wire insulation. Any material, including voltage that can be applied across the part in normal opera- this enamel (typically polyurethane) is susceptible tion?” to eventual chemical degradation when subject to For a part holding no specific agency approvals both input very high applied voltages thus implying that the and output should normally be maintained within SELV limits number of tests should be strictly limited. We there- i.e. less than 42.4V peak, or 60VDC. The isolation test volt- fore strongly advise against repeated high voltage age represents a measure of immunity to transient voltages isolation testing, but if it is absolutely required, that and the part should never be used as an element of a safety the voltage be reduced by 20% from specified test isolation system. The part could be expected to function cor- voltage. rectly with several hundred volts offset applied continuously 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 nised 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-acces- mented by a further insulation system of physical For full details go to www.murata-ps.com/rohs sible circuitry according to safety standard requirements. spacing or barriers. www.murata-ps.com/support KMP_78250C_C08 Page 1 of 3

78250 Series MAX250/MAX251 Compatible Converter Transformers PACKAGE SPECIFICATIONS MECHANICAL DIMENSIONS 6 Pin DIL 6 Pin SM 0.5 (12.70) 0.375 0.375 (9.52) MAX (9.52) Max. Primary Secondary Primary Secondary 1 6 1 6 (9.00.)3 M54ax. 78250C 2 (9.00.)3 M54ax. 78250MC 2 5* XYYWW 3 4 XYYWW 3 4 0.25 0.25 (6.35) (6.35) 0.135±0.02 0.012±0.30 (3.44±0.50) (0.008±0.20) 0.035 (0.90) 0.025 (0.63) 0.021 (0.53) 0.1 (2.54) 0.012(0.30) 0.025 (0.63) 0.008(0.20) 0.40 0.1 0.021 (0.53) (10.16) (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 6 Pin DIL 6 Pin SM 0.10 (2.54) 0.10 (2.54) 0.06 (1.60) 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 Pin finish Matte tin (10.95) Peak wave solder temperature 300˚C for 10 seconds Unless otherwise stated all 0.16 (4.00) dimensions in inches (mm) Peak reflow temperature 220˚C2 ±0.01 (0.25). 1 For further information, please visit www.murata-ps.com/rohs 0(.00.2630±±00..01055) (102.5.915) Tube length: 18.3±0.08 (465±2). 2 For high temperature reflow parts see 78250J Series. Tube material: Antistatic coated clear pvc. 0.22 (5.50) 0.15 (3.80) 0.62 (15.70) www.murata-ps.com/support KMP_78250C_C08 Page 2 of 3

78250 Series MAX250/MAX251 Compatible Converter Transformers TAPE & REEL SPECIFICATIONS REEL OUTLINE DIMENSIONS Ø15.039 (382) Max. 2.36 (60) Min. 0.94-1.08 (23.9-27.4)* Ø0.53 (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. (cid:103) Goods enclosure section 0.96 (24.4)(cid:103) 1.04 (26.4) Trailer section 6.3 (160) Min. Unless otherwise stated all dimensions in inches (mm) ±0.01(0.25). * Includes flange distortion at outer edge. Ø0.80 (20.20) Min. (cid:103) Measured at hub. TAPE OUTLINE DIMENSIONS 0.069 (1.75) 0.157 (4.00) 0.079 (2.00) 0.059 +- 00 .. 00 00 04 (1.50+ - 00 .. 10 00 ) 03.0+0120.+0.945 (24.00 )01.0-040.0- 0.453 (11.50) WWYYXC05287 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). This product is subject to the following operating requirements and the Life and Safety Critical Application Sales Policy: Refer to: http://www.murata-ps.com/requirements/ 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. © 2018 Murata Power Solutions, Inc. www.murata-ps.com/support KMP_78250C_C08 Page 3 of 3