NAE12S17-A

The NAE12S17-A is a 17-watt isolated DC-DC converter from Murata Power Solutions’ NAE series. This module provides a regulated 15V DC output from a 12V DC input with 1500 volts of galvanic isolation between input and output. The NAE series is designed for industrial and telecom applications requiring reliable, compact isolated power conversion. With its industry-standard DIP package footprint and through-hole mounting, the NAE12S17-A can be easily integrated into a wide variety of PCB designs. The module features a wide input voltage range of 9V to 18V (±50% of the 12V nominal), accommodating typical 12V bus variations and battery operation. The fully regulated output maintains tight line and load regulation of ±0.5% and ±1.0% respectively, ensuring stable power for sensitive analog and digital circuits. The NAE12S17-A incorporates comprehensive protection features including continuous short-circuit protection with auto-recovery, over-voltage protection, and thermal shutdown. The 1500VDC isolation rating meets safety standards for general-purpose industrial applications. The module operates at a fixed switching frequency of approximately 300 kHz, allowing the use of small external filter capacitors if additional ripple filtering is required. With an MTBF (Mean Time Between Failures) exceeding 1 million hours and operation across the full -40°C to +85°C temperature range (with appropriate derating at high temperatures), the NAE12S17-A provides the reliability required for industrial and telecommunications infrastructure applications.

The NAE12S17-A operates as an isolated flyback or forward topology DC-DC converter, using a high-frequency transformer to provide galvanic isolation between the input and output. The basic operation follows these steps: 1) Input Filtering: The 12V DC input passes through input filtering to reduce conducted noise and provide energy storage for transient loads. 2) Inverter Stage: A switching MOSFET chops the DC input voltage at high frequency (approximately 300 kHz), creating an AC square wave that drives the primary winding of the isolation transformer. 3) Isolation Transformer: The transformer provides galvanic isolation between the input and output sides while stepping the voltage up (or down) as needed. The turns ratio is designed to produce the desired 15V output after rectification. 4) Rectification: The AC voltage on the secondary side is rectified back to DC using Schottky diodes for low forward voltage drop and high efficiency. 5) Output Filtering: An LC filter smooths the rectified DC, reducing ripple to less than 75mV peak-to-peak. 6) Regulation: A feedback loop senses the output voltage and adjusts the switching duty cycle to maintain a constant 15V output despite changes in input voltage and load current. The feedback signal crosses the isolation barrier through an optocoupler or auxiliary winding. 7) Protection Circuits: If the output is short-circuited, the converter enters a current-limiting or hiccup mode to protect itself. Over-voltage and thermal shutdown circuits provide additional protection against fault conditions. The efficiency of up to 86% means that only about 14% of the output power is dissipated as heat, reducing thermal management requirements and improving overall system efficiency.

• Industrial PLC and distributed control system power supplies
• Telecommunications equipment isolated power rails
• Data networking and switchgear isolated interfaces
• Test and measurement instrument power supplies
• Medical devices requiring isolation (non-patient contact)
• 4-20mA current loop power supplies
• RS-485/RS-232 isolated interface power
• Battery-powered industrial sensor networks