DC-DC converter

01

Match the input range, output and losses

Mean Well's RSD-60 series specification lists 60 W railway DC-DC converters with continuous input ranges of 9–36 V DC (G models) or 18–72 V DC (L models) and outputs of 3.3, 5, 12 or 24 V; the 12 V models deliver 5 A. Typical efficiency ranges from 86.5% to 93% depending on model, voltage tolerance is ±2.0% including set-up, line and load regulation, and line and load regulation are each ±0.2% to ±0.5%. [1]

Maximum ripple and noise is 50–100 mV peak to peak by model, and Mean Well states it is measured at 20 MHz bandwidth with a 12-inch twisted-pair wire terminated with 0.1 µF and 47 µF capacitors in parallel; it also recommends external output capacitance not exceed 5000 µF. Overload protection acts at 105–135% of rated power as constant-current limiting. [1]

Mornsun's URB2405XYMD-10WR3 is a much smaller board-mount module: 10 W, 9–36 V input (4:1), 5 V output, efficiency up to 83%, in a 25.40 × 25.40 × 11.70 mm DIP package. [2]

Traco Power's TEN 8-2411WI, from its TEN 8WI series of 8 W modules with 4:1 input ranges and inputs up to 160 VDC across the series, takes 9–36 VDC and gives 5 VDC at 1,600 mA with 87% efficiency and 50 mVp-p typical ripple and noise; it is a metal-case DIP24 through-hole module of 31.8 × 20.3 × 10.2 mm weighing 18 g, rated −40 to 85 °C, with a 1,330 µF maximum capacitive load, remote on/off and EN 62368-1 and EN 50155 approvals. [4]

Editorial calculation: 5 V × 1.6 A = 8 W, and at 87% efficiency the module dissipates about 8 ÷ 0.87 − 8 ≈ 1.2 W; its 1,330 µF capacitive-load limit is about a quarter of the 5,000 µF Mean Well allows on the RSD-60, so check bulk capacitance on the load side against each datasheet. [4] [1]

Editorial calculation: at 92% efficiency a 60 W output draws about 60 ÷ 0.92 ≈ 65.2 W and dissipates about 5.2 W; at 83% the 10 W module dissipates about 10 ÷ 0.83 − 10 ≈ 2.0 W inside a 25 mm package. Compare heat at your actual load, and compare ripple only when the measurement bandwidth and capacitors match. [1] [2]

For a non-isolated buck stage built on a switching IC, TI's application note Basic Calculation of a Buck Converter's Power Stage (SLVA477, revised 2026) sets out the design inputs as the input range, nominal output voltage, maximum output current and the IC chosen. It computes the maximum duty cycle at the highest input as D = VOUT ÷ (VIN(max) × η), with η estimated at 85–90% or taken from the data sheet, and the inductor ripple current as ΔIL = (VIN(max) − VOUT) × D ÷ (fS × L); where the inductor is not yet known it estimates ripple at 20–40% of the maximum output current. It recommends Schottky rectifier diodes rated for the output current, and low-ESR X5R-or-better ceramic capacitors at input and output so capacitance is not lost to DC bias or temperature. [3]

Editorial calculation: for 24 V in and 12 V/5 A out at η = 0.9, D = 12 ÷ (24 × 0.9) ≈ 0.56, and the 20–40% rule puts inductor ripple at 1–2 A, so the switch must carry about 5.5–6 A peak (5 A + half the ripple); compare that with the IC's minimum switch current limit. [3]

Give the supplier the input voltage range, including transients and dropouts, the output voltage and current, isolation requirement, ripple limit and how it is to be measured, ambient temperature and cooling (free air, base plate), altitude, mounting and package, EMC and safety standards, protections, connectors and quantities.

02

Check isolation, derating and EMC

The RSD-60 withstand voltage is 4 kV DC input to output and 2.5 kV DC input or output to frame ground, with isolation resistance of 100 MΩ at 500 V DC. Mornsun's module is specified for 1500 V DC input-to-output isolation. [1] [2]

Traco Power lists the TEN 8-2411WI at 1,600 VDC input-to-output isolation and states its insulation system as "Functional Insulation"; an isolation test voltage alone does not tell you whether the barrier is rated as basic or reinforced safety insulation, so ask for the insulation grade and the standard it was assessed to. [4]

Mean Well rates the RSD-60 from −40 °C to +55 °C without derating, +70 °C at 60% load in free air, or +70 °C without derating on an external base plate, up to 5000 m; above 2000 m ambient temperature is derated by 3.5 °C per 1000 m for fanless models. Mornsun's module operates from −40 °C to +85 °C ambient. [1] [2]

Mean Well lists conducted emission to EN 55032 Class A and radiated Class B, immunity to the IEC 61000-4 series, and railway compliance to EN 50155, EN 45545-2 and EN 50121-3-2; it notes the EMC tests were made with the unit on a 360 × 360 mm metal plate and that the final equipment must be re-confirmed. Mornsun states its module meets CISPR 32/EN 55032 Class A without external components. [1] [2]

Editorial calculation: a fanless RSD-60 at 4000 m loses about (4000 − 2000) ÷ 1000 × 3.5 = 7 °C of ambient rating. [1]

03

Compare what suppliers offer

Suppliers linked to this page list DC-DC converters; each card links to the page reviewed.

Listings range from board-mount isolated modules and railway or industrial converters to forklift and electric-vehicle DC-DC converters.

04

Trace the converter components

This is a functional reference built from the sources cited; it is not one maker's design.

05

Fill the specification fields with values for your design

A DC-DC converter quotation needs values for your design. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.

06

Send the input, output and environment data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Input: [range; transients; dropouts]
Output: [voltage; current; ripple limit]
Isolation: [withstand voltage; standards]
Environment: [ambient; cooling; altitude]
EMC: [standards; class]
Build: [package; mounting; quantity]

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