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Mean Well DDR-120B-48 DC-DC Converter - 120W - 16.8~33.6V in 48V out 2.5A

Name: Mean Well DDR-120B-48 DC-DC Converter - 120W - 16.8~33.6V in 48V out 2.5A
Brand: Mean Well
SKU: DDR-120B-48
Price: 76.53 USD
Availability: InStock

$76.53 USD

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Model

12V out 120W 12V out 400W 24V out 120W 24V out 240W 24V out 480W 48V out 120W 48V out 240W 48V out.480W

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Overview

DDR-120B-48 is the 48V output model of this series: rated current 2.5A, rated power 120W, typical efficiency 91%.

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 functions. This series of models has various input options: 9~18V / 16.8~33.6V / 33.6~67.2V / 67.2~154V and various output options: 12V / 24V / 48V and can be used for industrial & railway control, security control, communication system and other fields. Suitable applications include DC buck/boost regulator, 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-120B-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 @24Vdc
HOLD UP TIME (Typ.): Please refer to page 7 Hold up Time( Load de-rating curve )

INPUT

VOLTAGE RANGE^Note.4: 16.8 ~ 33.6Vdc
EFFICIENCY (Typ.): 91%
DC CURRENT (Typ.): 5.6A @24Vdc
INRUSH CURRENT (Typ.): 5A @ 24Vdc
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: 24Vin (B - type) :Power ON≥16.8V , OFF≤16.5V

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^{Note 6}: Parameter Standard Test Level

Conducted BS EN/EN55032 Class B
Radiated BS EN/EN55032 Class B
Voltage Flicker BS EN/EN61000-3-3
EMC IMMUNITY^{Note 6}: 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 (except for 9~18Vin)

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

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 (A:12Vdc , B:24Vdc) , 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-120B-48 Block Diagram — Block Diagram

DDR-120B-48 Derating Curve — Derating Curve

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

DDR-120B-48 Inrush Current — Inrush Current

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

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

DDR-120B-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-120B-48 to power 48V networking equipment from a 24V DC bus?

Yes. The DDR-120B-48 steps up a 16.8–33.6V DC input to 48V at up to 2.5A (120W). This suits PoE switches, network routers, and telecom equipment that require a 48V supply, commonly deployed in industrial Ethernet or building automation networks fed by 24V DC infrastructure.

Is this converter suitable for powering 48V DC loads in a railway signaling cabinet?

The DDR-120B-48 operates from -40°C to +70°C (with derating per the derating curve), features 4KVdc isolation, and meets EN 50155 / IEC 60571, EN 50121-3-2 for EMC and EN 45545-2 for fire protection, making it robust for railway environments with wide temperature swings and electrical noise. Its 120W output at 48V can supply signaling relays, communication modules, or monitoring systems from a 24V trackside DC bus.

Can I use the DDR-120B-48 to create a 48V bus for PoE-powered IP cameras from a 24V solar system?

Yes. With a 16.8–33.6V input range, the DDR-120B-48 accepts voltage from a 24V solar battery bank and converts it to 48V at 2.5A. This is enough to power a small PoE switch serving several IP cameras in a remote surveillance application.

Can the DDR-120B-48 operate without ventilation in a dust-prone industrial environment?

The datasheet does not specify a forced-airflow requirement or an ingress rating for the unit. It can be mounted in a sealed enclosure as long as internal temperatures remain within the -40°C to +70°C operating range, with derating per the derating curve. For dusty environments, a sealed NEMA 12 or IP54 cabinet is recommended.

Is the DDR-120B-48 appropriate for charging 48V lithium battery packs?

The DDR-120B-48 is a DC-DC converter with a regulated 48V output (adjustable 48–56V). It is not specified as a battery charger, and the datasheet lists no CC/CV charge profiles or battery management features; its constant-current overload mode is a protection function, not charge control. For lithium battery charging, a dedicated charger with proper charge algorithms is required.

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