Mean Well DDR-120D-48 Power Supply - DC to DC Converter

Overview

DDR-120D-48 is the 48V output model of this series: rated current 2.5A, rated power 120W, typical efficiency 91.5%.

DDR-120 series is a 120W DIN Rail type DC-DC converter with main features including DIN rail-type easy installation, ultra slim width (32mm), 2:1 wide input voltage, fanless design, -40~+70℃ wide operating temperature, 4KVdc I/O isolation, 150% peak load, adjustable output voltage and full protective futore, increasing system insulation level and voltage drop compensation along cable...etc.

Features

Compliance to BS EN/EN50155 and BS EN/EN45545-2 railway standard
Width only 32mm
2:1 wide input range
-40~+70℃ wide working temperature
150% peak load capability
DC output adjustable
Cooling by free air convection
Can be installed on DIN rail TS-35/7.5 or 15
Protections: Short circuit / Overload / Over voltage / Input reverse polarity / Input under voltage protection
4KVdc I/O isolation(Reinforced isolation)
Conformal coating
3 years warranty

Specifications

DDR-120D-48Specifications from the official datasheet (2026-09-10 edition)

OUTPUT

DC VOLTAGE: 48V
RATED CURRENT: 2.5A
CURRENT RANGE: 0 ~ 2.5A
RATED POWER: 120W
PEAK CURRENT: 3.75A
PEAK POWER^Note.5: 180W (3sec.)
RIPPLE & NOISE (max.)^Note.2: 50mVp-p
VOLTAGE ADJ. RANGE: 48 ~ 56V
VOLTAGE TOLERANCE^Note.3: ±1.0%
LINE REGULATION: ±0.5%
LOAD REGULATION: ±1.0%
SETUP, RISE TIME: 500ms, 60ms @110Vdc
HOLD UP TIME (Typ.): Please refer to page 7 Hold up Time( Load de-rating curve )

INPUT

VOLTAGE RANGE^Note.4: 67.2 ~ 154Vdc
EFFICIENCY (Typ.): 91.5%
DC CURRENT (Typ.): 1.3A @110Vdc
INRUSH CURRENT (Typ.): 5A @110Vdc
INTERRUPTION OF VOLTAGE SUPPLY: EN50155:2021-comply with S1 level

PROTECTION

OVERLOAD: Normally works within 150% rated output power for more than 3 seconds and then constant current protection 105~135% rated output power with auto-recovery
OVER VOLTAGE: 57.6 ~ 67.2V Protection type : Shut down o/p voltage, re-power on to recover
REVERSE POLARITY: By internal MOSFET, no damage, recovers automatically after fault condition removed
UNDER VOLTAGE LOCKOUT: 110Vin (D - type):Power ON≥67.2V , OFF≤65V

ENVIRONMENT

WORKING TEMP.: -40 ~ +70℃ (Refer to "Derating Curve")
WORKING HUMIDITY: 5 ~ 95% RH non-condensing
STORAGE TEMP., HUMIDITY: -40 ~ +85℃, 5 ~ 95% RH non-condensing
TEMP. COEFFICIENT: ±0.03%/℃ (0 ~ 55℃)
VIBRATION: Component:10 ~ 500Hz, 5G 10min./1cycle, 60min. each along X, Y, Z axes; Mounting: Compliance to IEC61373
OPERATING ALTITUDE: 5000 meters

SAFETY & EMC

SAFETY STANDARDS: IEC 62368-1, UL 62368-1, EAC TP TC 004, AS/NZS 62368.1 approved; Design refer to UL508
WITHSTAND VOLTAGE: I/P-O/P:4KVdc I/P-FG:2.5KVdc O/P-FG:2.5KVdc
ISOLATION RESISTANCE: I/P-O/P, I/P-FG, O/P-FG:>100M Ohms / 500Vdc / 25℃/ 70% RH
EMC EMISSION: Parameter Standard Test Level

Conducted BS EN/EN55032 Class B
Radiated BS EN/EN55032 Class B
Voltage Flicker BS EN/EN61000-3-3 -----
Harmonic Current ----- -----
EMC IMMUNITY: BS EN/EN55035 , BS EN/EN61000-6-2(BS EN/EN50082-2)

Parameter Standard Test Level

ESD BS EN/EN61000-4-2 Level 3, 8KV air; Level 3, 6KV contact; criteria A
Radiated BS EN/EN61000-4-3 Level 3, 10V/m; criteria A
EFT / Burst BS EN/EN61000-4-4 Level 3, 2KV; criteria A
Surge BS EN/EN61000-4-5 Level 3, 1KV/Line-Line ;Level 3, 2KV/Line-Line-FG ;criteria A
Conducted BS EN/EN61000-4-6 Level 3, 10V; criteria A
Magnetic Field BS EN/EN61000-4-8 Level 4, 30A/m; criteria A
RAILWAY STANDARD: Compliance to BS EN/EN45545-2 for fire protection ; Meet BS EN/EN50155 / IEC60571 including IEC61373 for shock & vibration, BS EN/EN50121-3-2 for EMC

Parameter	Standard	Test Level
Conducted	BS EN/EN55032	Class B
Radiated	BS EN/EN55032	Class B
Voltage Flicker	BS EN/EN61000-3-3	-----
Harmonic Current	-----	-----

Parameter	Standard	Test Level
ESD	BS EN/EN61000-4-2	Level 3, 8KV air; Level 3, 6KV contact; criteria A
Radiated	BS EN/EN61000-4-3	Level 3, 10V/m; criteria A
EFT / Burst	BS EN/EN61000-4-4	Level 3, 2KV; criteria A
Surge	BS EN/EN61000-4-5	Level 3, 1KV/Line-Line ;Level 3, 2KV/Line-Line-FG ;criteria A
Conducted	BS EN/EN61000-4-6	Level 3, 10V; criteria A
Magnetic Field	BS EN/EN61000-4-8	Level 4, 30A/m; criteria A

OTHERS

MTBF: 1769.5K hrs min. Telcordia SR-332 (Bellcore) ; 214.5K hrs min. MIL-HDBK-217F (25℃)
DIMENSION: 32*125.2*102mm (W*H*D)
PACKING: 510g; 28pcs/15.3Kg/1.23CUFT

Test conditions and notes7

1. All parameters NOT specially mentioned are measured at normal input (C:48Vdc , D:110Vdc) , rated load and 25℃ of ambient temperature.
2. Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair-wire terminated with a 0.1μF & 47μF parallel capacitor.
3. Tolerance : includes set up tolerance, line regulation and load regulation.
4. Derating may be needed under low input voltage. Please check the derating curve for more details.
5. 3 seconds max., please refer to peak loading curves.
6. The power supply is considered as an independent unit, but the final equipment still need to re-confirm that the whole system complies with the EMC directives. For guidance on how to perform these EMC tests, please refer to “EMI testing of component power supplies.” (as available on https://www.meanwell.com//Upload/PDF/EMI_statement_en.pdf )
7. The ambient temperature derating of 3.5℃/1000m with fanless models and of 5℃/1000m with fan models for operating altitude higher than 2000m(6500ft).

Technical drawings

DDR-120D-48 Block Diagram — Block Diagram

DDR-120D-48 Derating Curve — Derating Curve

DDR-120D-48 Input Under-Voltage Protection — Input Under-Voltage Protection

DDR-120D-48 Inrush Current — Inrush Current

DDR-120D-48 Efficiency vs Load & Vin Curve — Efficiency vs Load & Vin Curve

DDR-120D-48 D D R - 1 2 0 series — D D R - 1 2 0 series

DDR-120D-48 Mechanical Specification — Mechanical Specification

Typical applications

Downloads

Certificates2

CE Certificate(DDR-120)(EN) PDF Download

EMC Certificate(DDR-120)(EN) PDF Download

Catalogues2

Mean Well DC-DC Catalog PDF Download

Mean Well Catalog (Industrial) PDF Download

FAQ

Can I use the DDR-120D-48 to power 48V PoE equipment from a 110V DC distribution bus?

Yes. The DDR-120D-48 accepts 67.2-154V DC input and outputs a regulated 48V at 2.5A (120W). This is sufficient for a small PoE switch or PoE injector in utility substations or railway installations where 110V DC buses are common. The 4KVdc input-to-output isolation separates the Ethernet equipment from the high-voltage bus.

Is the DDR-120D-48 a good fit for converting a 125V DC UPS output to 48V for telecom loads?

Yes, as long as the bus stays within the 67.2-154V input range, which includes a nominal 125V DC. The 120W at 48V/2.5A output can feed small telecom modules, fiber optic media converters, or 48V rack equipment. DIN rail mounting integrates easily into standard telecom distribution panels.

Can the DDR-120D-48 supply 48V to industrial Ethernet switches in a process control cabinet?

Yes. Many managed industrial Ethernet switches require 48V DC input, and 120W at 2.5A provides enough power for a mid-range switch plus a few PoE-powered field devices. The slim 32mm width helps conserve space in the control cabinet.

Will the DDR-120D-48 work in extreme-temperature outdoor enclosures?

It operates from -40°C to +70°C, with load derating at higher temperatures per the derating curve, so it covers cold starts down to -40°C but not ambients above +70°C. Install it inside a sealed enclosure to guard against moisture and particulate ingress, as the datasheet lists no IP rating for the converter.

How do the DDR-120 48V output models differ across the A, B, C, and D input ranges?

All four deliver 48V on a DIN rail mount. The DDR-120A-48 accepts 9-18V input at 100.8W/2.1A. The DDR-120B-48 accepts 16.8-33.6V at 120W/2.5A. The DDR-120C-48 accepts 33.6-67.2V at 120W/2.5A. The DDR-120D-48 accepts 67.2-154V at 120W/2.5A. The letter suffix identifies the input voltage range.

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Model	Power	Voltage	Current	IP Rating
Mean Well DDR-120D-24 DC-DC Converter - 120W - 67.2~154V in 24V out 5A	120W	24V	5A	IP20	View
Mean Well DDR-120D-12 DC-DC Converter - 120W - 67.2~154V in 12V out 10A	120W	12V	10A	IP20	View

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Mean Well DDR-120D-48 DC-DC Converter - 120W - 67.2~154V in 48V out 2.5A

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Overview

Features

Specifications

OUTPUT

INPUT

PROTECTION

ENVIRONMENT

SAFETY & EMC

OTHERS

Technical drawings

Typical applications

Downloads

Certificates2

Catalogues2

FAQ

Payment & Security

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Mean Well DDR-120D-48 DC-DC Converter - 120W - 67.2~154V in 48V out 2.5A

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