Murata 76250ENC, 76253/XXENC Converter Transformers
EN Approved MAX250/251/253 Compatible Converter Transformers
Features
- RoHS compliant ✔️
- Maxim MAX250/MAX251/MAX253 compatible
- EN62368-1 TUV certificate of compliance
- Isolation to 6kVDC
- Toroidal construction
- Industry-standard pinout
- UL 94 V-0 package materials
- Fully encapsulated
- Compatible with RoHS soldering systems
- Backward compatible with Sn/Pb soldering systems
Description
The 76250ENC converter transformer is specifically designed for use with Maxim chipsets to provide isolated RS232 interfaces. Its carefully controlled turns ratio ensures consistent performance, while a toroidal construction minimizes EMI.
The 76253/XXENC converter transformers are designed for use with the MAX253 chip set to provide isolated power supplies. The 5V version can supply 1W, and the 3.3V version can supply 500mW. A center-tapped secondary winding allows for full bridge, half bridge, or voltage doubling configurations.
Selection Guide
| Order Code | Input Voltage (V) | Output Voltage (V) | Max. Output Current (mA) | Isolation Voltage (VDC) | Turns Ratio |
|---|---|---|---|---|---|
| 76250ENC | 3.3 | 5.0 | 100 | 6000 | 1CT:1 |
| 76253/35ENC | 5.0 | 5.0 | 200 | 6000 | 1:5 |
| 76253/55ENC | 5.0 | 5.0 | 200 | 6000 | 1:1.33 |
76250ENC Characteristics
| Parameter | Conditions | Min. | Typ. | Max. | Units |
|---|---|---|---|---|---|
| Primary Inductance, Lp (1&5) | 10kHz, 100mV | 1.0 | 2.0 | 2.9 | mH |
| Leakage Inductance, Ll (1&5)2 | 100kHz, 100mV | 35 | 40 | μH | |
| Interwinding Capacitance, Cww (1&2)2 | 100kHz, 100mV | 1.5 | 3.0 | pF | |
| D.C. Resistance, RDC (1&5) | <0.1VDC | 1.0 | 2.0 | Ω | |
| Volt-time Product, Et (1&5) | 50 | Vμs |
76253/35ENC Characteristics
| Parameter | Conditions | Min. | Typ. | Max. | Units |
|---|---|---|---|---|---|
| Primary Inductance, Lp (1&5) | 100kHz, 250mV | 140 | 200 | μH | |
| Secondary Inductance, Ls (2&6) | 100kHz, 250mV | 700 | 1000 | μH | |
| Leakage Inductance, Ll (1&5)2 | 100kHz, 250mV | 5.0 | 7.0 | μH | |
| Interwinding Capacitance, Cww (1&2)2 | 100kHz, 250mV | 2.7 | 3.5 | pF | |
| D.C. Resistance, RDC (1&5) | <0.1VDC | 0.4 | 0.8 | Ω | |
| Volt-time Product, Et (1&5) | 25 | 35 | Vμs |
76253/55ENC Characteristics
| Parameter | Conditions | Min. | Typ. | Max. | Units |
|---|---|---|---|---|---|
| Primary Inductance, Lp (1&5) | 100kHz, 250mV | 80 | 150 | μH | |
| Secondary Inductance, Ls (2&6) | 100kHz, 250mV | 142 | 267 | μH | |
| Leakage Inductance, Ll (1&5)2 | 100kHz, 250mV | 7.0 | 10.0 | μH | |
| Interwinding Capacitance, Cww (1&2)2 | 100kHz, 250mV | 2.7 | 3.5 | pF | |
| D.C. Resistance, RDC (1&5) | <0.1VDC | 0.5 | 0.9 | Ω | |
| Volt-time Product, Et (1&5) | 30 | 40 | Vμs |
Absolute Maximum Ratings
| Parameter | Value |
|---|---|
| Operating free air temperature range 76250ENC | 0°C to 70°C |
| Operating free air temperature range 76253/XXENC | -40°C to 85°C |
| Storage temperature range | -50°C to 125°C |
| Lead temperature 1.5mm from case for 10 seconds | 300°C |
| Peak current, IPK 76250ENC | 300mA |
| Peak current, IPK 76253/XXENC | 400mA |
| Isolation voltage (flash tested for 1 second) | 6000VDC |
Soldering Information
Peak wave solder temperature: 300°C for 10 seconds
Pin finish: Matte tin
Technical Notes
Isolation Voltage
'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.
All products in this series are 100% production tested at their stated isolation voltage.
This series is certified by TUV to EN62368-1 with a working voltage of 300Vrms for Reinforced Insulation systems.
Repeated High-Voltage Isolation Testing
It is well known that repeated high-voltage isolation testing of a barrier component can degrade isolation capability, depending on materials, construction, and environment. Murata strongly advises against repeated high voltage isolation testing. If it is absolutely required, the voltage should be reduced by 20% from the specified test voltage.
Safety Approval
EN62368-1
The 7625xENC series has been certified by TUV to EN62368-1 for reinforced insulation to a working voltage of 300Vrms, 2500Vpk, and a working frequency of 30kHz. Operation above 30kHz requires system-level evaluation.
Working altitude: OVC II 5000m.
Creepage and clearance: 9.3mm.
Typical Characteristics
Voltage Curves
76253/35ENC: This graph illustrates the relationship between output voltage (V) and output current (mA). Two curves, 'FS=High' and 'FS=Low', show how output voltage varies with load current.
76253/55ENC: This graph shows output voltage (V) on the Y-axis versus output current (mA) on the X-axis. A single curve labeled 'FS=Low/High' indicates the output voltage behavior across the current range.
Efficiency Curves
76253/35ENC: This graph displays efficiency (%) on the Y-axis against output current (mA) on the X-axis. Curves for 'FS=High' and 'FS=Low' demonstrate efficiency performance under different conditions.
76253/55ENC: This graph shows efficiency (%) versus output current (mA). Curves for 'FS=High' and 'FS=Low' illustrate the efficiency characteristics.
Voltage Deviation
76253/35ENC: This graph plots voltage deviation from nominal 25°C output (%) on the Y-axis against temperature (°C) on the X-axis. Curves for 'FS=High' and 'FS=Low' show how voltage stability is affected by temperature.
76253/55ENC: This graph displays voltage deviation from nominal 25°C output (%) versus temperature (°C). Curves for 'FS=High' and 'FS=Low' indicate voltage stability across temperature ranges.
All curves are derived from testing with the Maxim MAX235 IC using the circuit shown in application note MPAN-03.
Package Specifications
Mechanical Dimensions
Overall dimensions are approximately 15.00 mm (0.59 in) in length and 12.50 mm (0.492 in) in height. The width is 12.00 mm (0.472 in). Pins are on a 2.54 mm (0.1 in) pitch.
Note: Pin 4 is not fitted for the 76250ENC model.
Pin Connections
76250ENC (Top View): Primary: Pins 1, 2. Secondary: Pins 3, 5, 6. (Pin 4 is not fitted).
76253/XXENC (Top View): Primary: Pins 1, 2. Secondary: Pins 3, 4, 5, 6.
Tube Dimensions
Tube length is 480±2.00 mm (18.90±0.079 in) with a quantity of 30 units. The tube material is antistatic coated clear PVC. Dimensions are in mm (inches) with tolerances of -0.00 +0.50 (-0.00 +0.020).
Recommended Footprint Details
The footprint features holes with a diameter of Ø1.00+0.15-0.00 mm (Ø0.039+0.006-0.000 in). Holes may be omitted for variants with fewer than 6 pins. All pins are on a 2.54 mm (0.1 in) pitch and within ±0.25 mm (0.01 in) of true position.
Disclaimer
All products are designed for standard commercial and industrial applications and are not intended for safety-critical or life-critical applications. Any use of Murata standard products in such applications without prior explicit written approval from Murata is considered unauthorized use.
Examples of applications not suitable for these products without explicit approval include: Aircraft equipment, Aerospace equipment, Undersea equipment, Power plant control equipment, Medical equipment, Transportation equipment (automobiles, trains, ships, etc.), Traffic signal equipment, Disaster prevention/crime prevention equipment, and Data Processing equipment.
Murata provides no express or implied warranty regarding suitability, fitness for purpose, or compatibility. The buyer is solely responsible for ensuring the product's suitability and compatibility with their application.
The buyer must have the expertise to implement safeguards against dangerous consequences of failures, monitor failures, and take remedial actions. The buyer will indemnify Murata against damages arising from unauthorized use in safety-critical or life-critical applications.
Murata Power Solutions (Milton Keynes) Ltd. makes no representation regarding patent rights or licenses for circuits described herein. Specifications are subject to change without notice.
This product is subject to specific operating requirements and the Life and Safety Critical Application Sales Policy. Refer to: https://www.murata.com/en-eu/products/power/requirements
For more information, visit www.murata.com.
