The MEAN WELL DDR-120D-12 is an isolated DIN rail DC/DC converter providing 12 V at up to 10 A (120 W). Its D-code input accepts 67.2–154 VDC. The 32 mm-wide, fanless metal enclosure mounts on TS-35/7.5 or TS-35/15 rail. Adjustable output, 4 kVDC reinforced input-to-output isolation and short-duration peak capability support industrial control, transport and communications equipment within the ratings below.
Product Datasheet
Download MEAN WELL DDR-120 Datasheet (PDF)
The DDR-120 section is on PDF pages 14, 15, 16, 17, 18, 19, 20, 21, 22. Refer to the complete mechanical drawings and notes when planning installation.
Model and Output Ratings
| Full model |
DDR-120D-12 |
| Series |
DDR-120 |
| Input code |
D: 110 VDC nominal test input |
| Output code |
12: 12 VDC nominal output |
| DC output voltage |
12 V |
| Rated output current |
10 A |
| Rated output power |
120 W |
| Output current range |
0–10 A |
| Output voltage adjustment |
9–14 V |
| Maximum ripple and noise |
50 mVp-p |
| Voltage tolerance |
±1.0% |
| Line regulation |
±0.5% |
| Load regulation |
±1.0% |
Choose the load using the ratings of this complete model. The series name does not mean that every input version delivers 120 W.
DC Input and Performance
| Specified DC input range |
67.2–154 VDC |
| Typical efficiency |
89.5% |
| Typical input current |
1.3 A at 110 VDC |
| Typical inrush current |
5 A at 110 VDC |
| Set-up / rise time |
500 / 60 ms at 110 VDC |
| Input undervoltage thresholds |
Power on ≥67.2 V; power off ≤65 V |
| Supply-interruption classification |
EN 50155:2021, S1 |
| Hold-up time |
Load-dependent; see the DDR-120D-12 curve on PDF page 20 |
| Switching frequency |
65 kHz, as shown in the block diagram |
Unless otherwise specified, catalogue measurements use 110 VDC input, rated load and 25°C ambient. Efficiency and input current are typical values, not guarantees at every operating point.
Ripple and noise are measured with 20 MHz bandwidth and a 12-inch twisted pair terminated by 0.1 µF and 47 µF capacitors in parallel. Voltage tolerance includes set-up tolerance, line regulation and load regulation.
During start-up, a current-limiting circuit suppresses inrush. A MOSFET bypass reduces losses after start-up.
Short-Duration Peak Loads
| Catalogue peak current |
15 A |
| Catalogue peak power |
180 W |
| Maximum peak duration |
3 seconds; subject to the peak-loading and derating curves |
| Catalogue loading example 1 |
100% base load for 100 seconds, followed by 150% load for 3 seconds |
| Catalogue loading example 2 |
40% base load for 10 seconds, followed by 150% load for 3 seconds |
The peak rating is for short load events, not continuous output. Follow the complete temperature, input-voltage and repetition conditions on PDF page 17. The two loading diagrams are specific examples; they do not establish a universal duty cycle for every application.
Protection
| Short-circuit protection |
Included |
| Overload protection |
After the short peak-load interval, constant-current limiting at 105–135% of rated output power; automatic recovery |
| Overvoltage threshold |
14.4–16.8 V |
| Overvoltage recovery |
Output shuts down; reapply input power to recover |
| Input reverse-polarity protection |
Internal series MOSFET in the negative input opens on reversed polarity; automatic recovery after the fault is removed |
| Input undervoltage protection |
Output shuts down below the control threshold and restarts automatically when the input voltage recovers |
Limit planned peak operation to the 3-second maximum stated in the specification note. Do not use the overload-protection delay as a continuous-load rating.
Cooling, Derating and Environment
| Cooling |
Fanless free-air convection; vertical mounting |
| Working temperature |
−40 to +70°C, with derating |
| Continuous thermal loading |
100% through +55°C; 80% at +60°C; 40% at +70°C, following the linear derating curve |
| Low-input loading |
90% in the low-input region below 86.4 VDC; full rated load from 86.4 VDC within the specified range |
| Working humidity |
5–95% RH, non-condensing |
| Storage temperature and humidity |
−40 to +85°C; 5–95% RH, non-condensing |
| Temperature coefficient |
±0.03%/°C from 0 to 55°C |
| Operating altitude |
Up to 5000 m; reduce the allowed ambient temperature by 3.5°C per 1000 m above 2000 m |
| Component vibration test |
10–500 Hz, 5 G; 10 minutes per cycle, 60 minutes on each X, Y and Z axis |
| Mounting vibration reference |
IEC 61373 |
Apply temperature and low-input derating together. The 70°C operating limit does not mean full continuous power is available at 70°C. Maintain the intended vertical orientation and an unobstructed convection path.
Dimensions, Connections and Installation Parts
| Dimensions, W × H × D |
32 × 125.2 × 102 mm |
| Mechanical case |
221; drawing tolerance ±1 mm |
| Compatible DIN rails |
TS-35/7.5 or TS-35/15 |
| Input terminal block TB1 |
Pin 1: FG; pin 2: DC input −Vin; pin 3: DC input +Vin |
| Output terminal block TB2 |
Pins 1 and 2: DC output −Vo; pins 3 and 4: DC output +Vo |
| Output adjustment |
Front-panel voltage adjustment; use the model-specific adjustment range |
| Internal input fuse reference |
1 × Conquer MST, 4 A / 250 V; time-lag type |
Use the terminal numbers on the mechanical drawing on PDF page 22 and observe input/output polarity and frame-ground connections. The two side holes marked “No Use” are not mounting points.
TS-35/7.5 and TS-35/15 identify the supported mounting-rail profiles. The catalogue does not state that a rail is supplied. Conquer MST identifies the internal fuse component and rating, not an additional MEAN WELL accessory included with the converter.
Isolation and Standards
| Input-to-output isolation |
4 kVDC, reinforced isolation |
| Input-to-FG withstand voltage |
2.5 kVDC |
| Output-to-FG withstand voltage |
2.5 kVDC |
| Insulation resistance |
Input–output, input–FG and output–FG: >100 MΩ at 500 VDC, 25°C and 70% RH |
| Catalogue-listed safety approvals |
IEC 62368-1, UL 62368-1, EAC TP TC 004 and AS/NZS 62368.1 |
| Safety design reference |
UL 508 |
| EMC emission |
BS EN / EN 55032: Class B conducted and radiated emissions |
| EMC immunity |
BS EN / EN 55035 and BS EN / EN 61000-6-2; listed tests use performance criterion A |
| Railway references |
BS EN / EN 50155; IEC 60571; IEC 61373 shock and vibration; BS EN / EN 45545-2 fire protection |
| Railway EMC reference |
BS EN / EN 50121-3-2 |
The final equipment must still be checked for compliance with applicable EMC requirements. PDF page 21 records material-specific EN 45545-2 fire tests and environmental tests; these results do not certify every completed system or installation.
Mass and Catalogue References
| Mass, catalogue PACKING reference per unit |
510 g |
| Catalogue packing |
510 g; 28 units / 15.3 kg / 1.23 CUFT |
| Minimum MTBF |
1769.5K hours, Telcordia SR-332; 214.5K hours, MIL-HDBK-217F at 25°C |
| Catalogue warranty |
3 years |
The stated mass is the single-unit reference in the catalogue PACKING field. It is not a measured shipment weight.
