MEAN WELL SD-50A-24 is an enclosed, isolated single-output DC/DC converter delivering 24 V at up to 2.1 A, with a rated output of 50.4 W. The A-input version accepts 9.2–18 VDC. Its fanless metal enclosure uses free-air convection, with model-specific temperature derating and screw-terminal connections.
Product Datasheet
Download MEAN WELL SD-50 Datasheet (PDF)
The SD-50 section is on PDF pages 5, 6. Refer to the complete mechanical drawings and notes when planning installation.
Model and DC Output
| Full model |
SD-50A-24 |
| Series |
SD-50 |
| Input version |
A: 9.2–18 VDC |
| Output code |
24: 24 VDC |
| DC output voltage |
24 V |
| Rated output current |
2.1 A |
| Rated output power |
50.4 W |
| Output current range |
0–2.1 A |
| Output voltage adjustment |
23–30 V |
| Maximum ripple and noise |
150 mVp-p |
| Voltage tolerance |
±1.0% |
| Line regulation |
±0.2% |
| Load regulation |
±0.2% |
Input and Conversion Characteristics
| Permitted input voltage |
9.2–18 VDC |
| Typical efficiency |
74% |
| DC input current |
7 A at 12 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 12 VDC |
| Factory screening |
100% full-load burn-in test |
Unless otherwise specified, the catalogue parameters use 12 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 |
31.5–37.5 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 40°C, then derating to 70% 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 |
159 × 97 × 38 mm |
| Mechanical drawing reference |
Case No. 901; dimensions in mm, general tolerance ±1 mm |
| Unit mass |
430 g; catalogue PACKING reference per unit |
| Nominal switching frequency in block diagram |
83 kHz |
| Terminal 1 |
DC input V+ |
| Terminal 2 |
DC input V− |
| Terminal 3 |
FG / chassis ground |
| Terminal 4 |
DC output −V |
| Terminal 5 |
DC output +V |
The drawing shows two bottom M3 and three side M3 positions, with 78 mm between the bottom mounting positions and 117 mm between the outer side positions. Use the matching drawing for the remaining locations.
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 |
3293.1 thousand hours minimum |
| MTBF, MIL-HDBK-217F |
512.8 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.
