AC/DC 50W Metal Enclosed Switching Power Supply LM50-20Bxx (-Q) Series

19 de enero de 2026

Product Overview
The LM50-20Bxx series is a high-performance, cost-effective metal enclosed switching power supply. It features a wide universal input voltage range, suitability for both AC and DC input, high efficiency, and low standby power consumption. With high reliability and excellent safety isolation, it meets rigorous EMC and safety standards including IEC/EN/UL62368-1, CISPR32/EN55032 Class B, and IEC/EN60335-1. This series is designed for a broad spectrum of applications, including industrial controls, LED lighting, security systems, telecommunications, and smart home devices.

Key Features

Universal Input Range: 85 - 264VAC / 120 - 370VDC (same terminals).
High Efficiency: Typical efficiency up to 90%, with low no-load power consumption.
Wide Operating Temperature: Reliable performance from -30°C to +70℃.
High Isolation: Reinforced insulation with 4000VAC isolation voltage.
Comprehensive Protections: Includes short circuit, overload, and overvoltage protection.
High Altitude Operation: Suitable for applications up to 5000 meters.
Compact Design: High power density in a compact metal enclosure.
Safety Compliance: Conforms to Overvoltage Category III (per EN62477).

Model Selection Guide
All models in the LM50-20Bxx series comply with relevant safety and EMC standards. The standard series and the "Q" variant (LM50-20Bxx-Q) with conformal coating are available for enhanced environmental protection.

Model LM50-20B05: Output Power 50W. Rated Output 5VDC at 10A. Adjustable range: 4.5-5.5V. Typical efficiency: 87% (230VAC). Max. capacitive load: 8000µF.
Model LM50-20B12: Output Power 50W. Rated Output 12VDC at 4.5A. Adjustable range: 10.2-13.8V. Typical efficiency: 89% (230VAC). Max. capacitive load: 1500µF.
Model LM50-20B15: Output Power 52.5W. Rated Output 15VDC at 3.5A. Adjustable range: 13.5-18V. Typical efficiency: 89% (230VAC). Max. capacitive load: 1000µF.
Model LM50-20B24: Output Power 52.8W. Rated Output 24VDC at 2.2A. Adjustable range: 21.6-28.8V. Typical efficiency: 90% (230VAC). Max. capacitive load: 750µF.

Detailed Specifications

Input Characteristics

Input Voltage: 85 - 264 VAC; 120 - 370 VDC.
Input Frequency: 47 - 63 Hz.
Input Current: Max. 1.2A (115VAC); Max. 0.65A (230VAC).
Inrush Current: Max. 40A (115VAC, cold start); Max. 60A (230VAC).
Leakage Current: <0.75 mA at 240VAC.
No-load Power Consumption: <0.3W (Typical).
Hot Plug-in: Not supported.

Output Characteristics

Output Voltage Accuracy: ±1%.
Line Regulation: ±0.5% (Typical).
Load Regulation: ±1% for 5V model; ±0.5% for 12V, 15V, 24V models (0% to 100% load).
Ripple & Noise (Peak-to-Peak, 20MHz BW): 80mV (5V); 120mV (12V/15V); 150mV (24V).
Temperature Coefficient: ±0.03%/°C.
Minimum Load: 0%.
Hold-up Time: 20ms (115VAC); 50ms (230VAC).
Short Circuit Protection: Hiccup mode, self-recovering.
Over Current Protection (OCP): Self-recovering (120% - 150% of Io).
Over Voltage Protection (OVP): Hiccup mode, self-recovering. Thresholds: ≤6.75VDC (5V); ≤16.2VDC (12V); ≤21.75VDC (15V); ≤33.6VDC (24V).

General Characteristics

Isolation Voltage: 4000VAC input to case; 2000VAC input to output.
Insulation Resistance: ≥100 MΩ.
Operating Temperature: -30°C to +70℃ (with derating above 50°C).
Storage Temperature: -40°C to +85℃.
Operating/Storage Humidity: 20% to 95% RH, non-condensing.
Switching Frequency: 65 kHz (Typical).
Safety Standards: Certified to BS EN/EN62368-1, UL62368-1, GB4943.1; complies with IEC/EN60335-1, IEC/EN61558.
MTBF: ≥300,000 hours (MIL-HDBK-217F, 25°C).
Warranty: 3 years (case temperature <70°C).

Physical & EMC Characteristics

Enclosure: Metal (AL1100, SGCC).
Dimensions: 119.0 x 96.5 x 30.0 mm.
Weight: 200g (Typical).
Cooling: Natural convection (fanless).
EMI Conformance: CISPR32/EN55032 Class B (Conducted & Radiated).
EMS Immunity: Compliant with IEC/EN61000-4-2 (ESD: ±6kV contact, ±8kV air), IEC/EN61000-4-3 (10V/m), IEC/EN61000-4-4 (±2kV), IEC/EN61000-4-5 (Surge: ±2kV line-line, ±4kV line-PE), IEC/EN61000-4-6 (10V), IEC/EN61000-4-8 (30A/m), and voltage dip/interruption standards.

Mechanical & Installation Data

Pin Assignment (5-pin terminal):
1. AC Line (L)
2. AC Neutral (N)
3. Earth Ground (FG)
4. -Vo
5. +Vo
Mounting: Use M3 screws. Max screw length: 5mm (side holes), 3mm (top/bottom holes). Recommended torque: 0.4 N·m ±10%.
Wiring: Recommended wire gauge: 22-12 AWG.
Output Adjustment: Via ADJ potentiometer (clockwise to increase voltage).
Critical Note: The unit's metal case must be securely connected to the system's protective earth (FG) for safety and proper EMC performance. For use in enclosed environments or specific application guidance, contact technical support.