MEAN WELL SD-25C-12 is an enclosed, isolated single-output DC/DC converter delivering 12 V at up to 2.1 A, with a rated output of 25.2 W. The C-input version accepts 36–72 VDC. Its fanless metal enclosure uses free-air convection, with model-specific temperature derating and screw-terminal connections.
Product Datasheet
Download MEAN WELL SD-25 Datasheet (PDF)
The SD-25 section is on PDF pages 3, 4. Refer to the complete mechanical drawings and notes when planning installation.
Model and DC Output
| Full model |
SD-25C-12 |
| Series |
SD-25 |
| Input version |
C: 36–72 VDC |
| Output code |
12: 12 VDC |
| DC output voltage |
12 V |
| Rated output current |
2.1 A |
| Rated output power |
25.2 W |
| Output current range |
0–2.1 A |
| Output voltage adjustment |
11–16 V |
| Maximum ripple and noise |
120 mVp-p |
| Voltage tolerance |
±1.0% |
| Line regulation |
±0.3% |
| Load regulation |
±0.3% |
Input and Conversion Characteristics
| Permitted input voltage |
36–72 VDC |
| Typical efficiency |
78% |
| DC input current |
0.8 A at 48 VDC |
| Cooling |
Free-air convection; fanless |
| Input filtering |
Built-in EMI filter |
| Catalogue input-range feature |
2:1 wide input range |
| Set-up / rise time at full load |
2.5 s / 50 ms at 48 VDC |
| Factory screening |
100% full-load burn-in test |
Unless otherwise specified, the catalogue parameters use 48 VDC input, rated load and 25°C ambient. Select the input version before wiring; the input range is specific to the letter in the complete model number.
Ripple and noise are measured with 20 MHz bandwidth using a 12-inch twisted pair terminated with parallel 0.1 µF and 47 µF capacitors. Voltage tolerance includes set-up tolerance, line regulation and load regulation.
Protection
| Short-circuit protection |
Included |
| Overload threshold |
105–150% of rated output power |
| Overload response |
Hiccup mode; automatic recovery after the fault is removed |
| Overvoltage threshold |
16.8–20 V at 10% load |
| Overvoltage response |
Hiccup mode; automatic recovery after the fault is removed |
Operate within both the output current and output power ratings; the overload threshold is a protection characteristic, not a continuous or timed peak-output rating.
Environment and Derating
| Working ambient temperature |
−10 to +60°C, subject to derating |
| Working humidity |
20–90% RH, non-condensing |
| Storage temperature / humidity |
−20 to +85°C / 10–95% RH |
| Temperature coefficient |
±0.03%/°C over 0–50°C |
| Vibration |
10–500 Hz; 2 G; 10 min/cycle; 60 min along each X, Y and Z axis |
The low-temperature curve rises from 80% load at −10°C to 100% at 0°C. Full load is shown through 50°C vertical / 45°C horizontal, then derating to 80% at 60°C vertical / 55°C horizontal.
Observe the corresponding horizontal/vertical curve when positioning the enclosure. The operating-temperature range does not mean full output is available at every temperature.
For fanless operation above 2000 m altitude, the catalogue note reduces the allowable ambient temperature by 3.5°C per additional 1000 m. This derating note does not independently specify a maximum installation altitude.
Mechanical Details and Terminal Connections
| Dimensions, L × W × H |
99 × 97 × 36 mm |
| Mechanical drawing reference |
Case No. 905; dimensions in mm, general tolerance ±1 mm |
| Unit mass |
380 g; catalogue PACKING reference per unit |
| Nominal switching frequency in block diagram |
83 kHz |
| Terminal 1 |
DC output −V |
| Terminal 2 |
DC output +V |
| Terminal 3 |
FG / chassis ground |
| Terminal 4 |
DC input V+ |
| Terminal 5 |
DC input V− |
The drawing shows two bottom M3 and two side M3 mounting positions, with 55 mm bottom-hole and 74 mm side-hole spacing. Use the matching drawing for hole locations and enclosure clearance.
Wire the numbered terminals according to this model-specific assignment, including the FG/chassis terminal. Maintain free-air convection around the enclosure. Use the output-voltage adjuster only within the specified adjustment range.
The catalogue mechanical pages specify the enclosure and screw-terminal connections. No separately orderable model-specific cable, terminal housing or mounting accessory is identified on these series pages.
Safety, EMC and Reliability
| Catalogue safety / design references |
EAC TP TC 004 approved; design reference to AS/NZS 62368.1 and LVD |
| Withstand voltage, input to output |
1.5 kVAC |
| Withstand voltage, input to FG |
2 kVAC |
| Withstand voltage, output to FG |
0.5 kVAC |
| Insulation resistance |
100 MΩ at 500 VDC, 25°C and 70% RH; input–output, input–FG and output–FG |
| EMC emission references |
BS EN/EN 55032 (CISPR 32) Class B; EAC TP TC 020 |
| EMC immunity references |
BS EN/EN 61000-4-2, -3, -4, -6 and -8; BS EN/EN 55035; EAC TP TC 020 |
| EMC environment in catalogue |
Heavy industry |
| MTBF, Telcordia SR-332 |
3682.6 thousand hours minimum |
| MTBF, MIL-HDBK-217F |
528.8 thousand hours minimum at 25°C |
| Catalogue warranty period |
2 years; subject to manufacturer terms |
Design references and the catalogue approval statements have different meanings. The converter is a component for installation in end equipment; these references do not certify the completed system.
The EMC test arrangement mounts the converter on a 360 × 360 × 1 mm metal plate. The manufacturer requires EMC compliance to be reconfirmed in the completed installation. MTBF figures are reliability calculations, not a service-life guarantee.
