A2412S-2WRS

The A2412S-2WRS is a 2-watt isolated DC-DC converter module from MORNSUN’s A_S-2WR2 series, designed for general-purpose PCB mounting applications requiring galvanic isolation between input and output circuits. With a 24V nominal input (21.6V to 26.4V range) and a regulated 12V single output rated at 167mA, this module provides a compact and efficient power solution for distributed power architectures. The 1500VDC isolation rating provides electrical separation between input and output, helping to break ground loops, reduce noise coupling, and enhance system safety. The module achieves high efficiency up to 86%, minimizing power loss and thermal rise in the application. The SIP-7 single-in-line package with dimensions of just 19.65 x 7.05 x 10.16mm provides excellent power density for space-constrained designs. Operating temperature range extends from -40 degC to +105 degC, with power derating required above 85 degC for reliable operation. No external components are required for basic operation, simplifying design and reducing bill of materials. For applications requiring stricter electromagnetic compliance, external filter components can be added to achieve CISPR32/EN55032 Class B EMC performance. The module features a plastic case with UL94V-0 flame-retardant rating and is compatible with wave soldering processes. With an MTBF (mean time between failures) rating of 3.5 million hours per MIL-HDBK-217F at 25 degC, the A2412S-2WRS provides high reliability for demanding applications. A minimum load of 10% of rated output is recommended to ensure stable operation across all conditions. The A2412S-2WRS is widely used in industrial control systems, instrumentation and measurement equipment, communication devices, data acquisition systems, and other applications requiring isolated power conversion in a compact form factor.

The A2412S-2WRS is a fixed-frequency flyback DC-DC converter that operates by switching the input DC voltage at high frequency (typically 100 kHz) through a transformer to provide galvanic isolation and voltage transformation between the input and output. The converter consists of several key functional blocks: an input filter that conditions the input voltage and suppresses switching noise reflected back to the source; an oscillator and switching regulator that controls the power MOSFET to drive the transformer primary; a transformer that provides galvanic isolation and steps the voltage to the desired output level; a rectifier (typically a Schottky diode for low forward drop) that converts the high-frequency AC from the transformer secondary back to DC; an output filter capacitor that smooths the rectified output to provide low-ripple DC; and a feedback control loop that regulates the output voltage by adjusting the switching duty cycle. The flyback topology stores energy in the transformer’s magnetic field during the switch ON time and delivers it to the output during the switch OFF time, making it naturally suited for isolated step-down (or step-up) conversion with relatively low power levels. The isolation is provided by the transformer’s primary-to-secondary insulation, which is rated at 1500VDC for this device. The switching frequency of approximately 100 kHz represents a balance between component size (higher frequency allows smaller magnetics and capacitors) and switching losses (higher frequency increases losses and reduces efficiency). The regulation is achieved through a feedback mechanism that samples the output voltage and adjusts the duty cycle accordingly. For isolated converters like this, the feedback signal is typically transferred across the isolation boundary using either an optocoupler or a transformer-coupled feedback winding. The converter enters discontinuous conduction mode at light loads, which can increase output ripple; hence the recommendation for a minimum 10% load to maintain stable operation and specified performance.

• Industrial PLC and distributed control system isolated power supplies
• Instrumentation and measurement system isolated sensor interfaces
• Telecommunication and networking equipment isolated rails
• 4-20mA current loop transmitter power supplies
• Data acquisition and signal conditioning isolated circuits
• Portable and battery-powered instrumentation
• Medical equipment isolated auxiliary power (non-patient contact)
• Building automation and HVAC control systems
• Test and measurement equipment isolation barriers