TDK-Lambda Launches 120 W and 240 W DIN-Rail DC-DC Converters

TDK Corporation has introduced the TDK-Lambda DDSM series, a pair of programmable, isolated DC-DC converters that mount on standard DIN rails and deliver 120 W or 240 W of output power. The converters combine wide input and output voltage ranges with remote programming and real-time monitoring over a Modbus interface, targeting factory automation, semiconductor fabrication, renewable power generation, telecommunications, and test and measurement systems.

120 W and 240 W programmable DC-DC converters. Image used courtesy of TDK

Wide Conversion Ratios Cut Part Counts

Both models accept a nominal input of 12 V to 48 V (10.8 V to 52.8 V maximum) and produce an adjustable output of 5 V to 55 V (4.7 V to 57 V maximum). The 120 W DDSM120 supplies up to 5 A, while the 240 W DDSM240 supplies up to 10 A. Efficiency reaches up to 93% in standard operation, which TDK says reduces internal heating losses and cuts energy consumption in standby mode.

The series' defining feature, however, is its wide conversion ratio. Because the output can be programmed anywhere from 5 V to 55 V regardless of where the input sits in its 12 V to 48 V range, a single DDSM unit can step a distribution bus up or down as the application demands.

Block diagram. Image used courtesy of TDK

TDK cites several scenarios the flexibility serves, such as stabilizing voltage at the end of long cable runs, generating a higher rail to support heavily loaded systems, supplying an independent isolated voltage for power-over-ethernet (PoE) equipment, and powering loads that require nonstandard operating voltages.

Where a control cabinet previously required several fixed-output converters with different part numbers, one programmable unit can now cover the full span, reducing the number of items an OEM or maintenance operation needs to stock. In addition, the isolated design withstands 2,200 VDC from input to output, input to case, and output to case, allowing the output to be referenced independently of the input bus, a requirement for the PoE and instrumentation cases TDK highlights.

Programming and Monitoring Over Modbus

Setup and supervision run through TDK-Lambda's PowerCMC control and monitoring center software, which communicates with the converter via Modbus over USB. The interface provides remote output programming and real-time monitoring of the operating state. For hands-on adjustment, a front-panel digital display shows device settings, system alarms, and status information, and three push buttons allow manual operation without a connected PC.

A 24 V DC-OK signal is accessible from the front panel for wiring into supervisory or alarm circuits, and push-in terminals simplify installation in crowded cabinets. The PowerCMC software is a free download from TDK-Lambda's product site.

Specifications and Compliance

Each converter measures 40 mm wide, 116.6 mm deep, and 115 mm high, weighs 500 g, and operates by convection cooling across a -25°C to 70°C temperature range. The units switch at 100 kHz, hold ripple and noise to 200 mVpp or less, and require no minimum load.

Protection features include overcurrent protection selectable between hiccup and constant-current behavior, overvoltage protection capped at 62 V, and overtemperature protection with automatic recovery. Parallel operation is supported for higher current; series operation isn't. TDK-Lambda quotes a calculated MTBF of 1,173,000 hours per Telcordia SR-332 and backs the series with a three-year warranty.

DDSM outline drawing. Image used courtesy of TDK

The DDSM series is certified to IEC/EN/UL/CSA 61010-1 and 61010-2-201 as well as IEC/EN/UL/CSA 62368-1 (Ed. 3), and carries CE and UKCA markings under the Low Voltage, EMC, and RoHS directives and their UK equivalents. Radiated and conducted emissions meet EN 55032-B, and immunity meets the EN 61000-6 industrial standards, including 4 kV contact and 8 kV air ESD withstand and 10 V/m radiated susceptibility, all to criteria A. Vibration and shock ratings of 2 g and 30 g, respectively, per IEC 60068-2 round out the ruggedization picture.

The DDSM launch extends TDK-Lambda's DIN-rail family, which spans the DRB three-phase and D1SE AC-DC supplies and the DUSH uninterruptible DC supplies, and adds a rare DC-DC entry to that lineup. It follows the company's recent introduction of non-isolated buck-boost DC-DC converters rated at up to 99% efficiency. Both DDSM models are available now through TDK-Lambda's sales channels.