Lambda / TDK / EMI LPD421A-FM

The Lambda/TDK/EMI LPD421A-FM is a dual-output regulated DC power supply engineered for laboratory and rack-mounted applications requiring stable, independent voltage control. Each output adjusts from 0 to 20 VDC independently, with series/parallel configurations supporting 0–40 VDC and current expansion to 3.4 A. The supply delivers exceptional line and load regulation of 0.01% + 1 mV, output ripple of 500 µV RMS (1.5 mV pk-pk), and temperature stability of (0.015% + 0.5 mV)/°C across a 0°C to +60°C continuous duty range.

Technical Specifications

• Voltage: 0–20 VDC per output; 0–40 VDC in series configuration


• Current per output: 1.7 A @ 30°C; 1.5 A @ 40°C; 1.3 A @ 50°C; 1.0 A @ 60°C


• Series/parallel current: up to 3.4 A


• Line/load regulation: 0.01% + 1 mV


• Output ripple: 500 µV RMS / 1.5 mV pk-pk


• Temperature coefficient: (0.015% + 0.5 mV)/°C Input Power


• AC voltage: 105–132 VAC, 187–242 VAC, or 205–265 VAC (configuration dependent)


• Frequency: 47–440 Hz (derate 10% for 47–53 Hz operation) Physical & Thermal


• Dimensions: 5-3/16" H × 8-3/8" W × 10-5/8" D


• Weight: 13 lbs net / 16 lbs shipping


• Cooling: Convection design; no blowers or external heat sinks required


• Panel finish: Tan glass-filled, flame-retardant nylon

Key Features

• Five-way binding posts on front panel for each output


• Remote sensing provision to compensate for lead resistance effects


• Remote programmable voltage control


• Series/parallel and auto series/parallel (master-slave) tracking capability


• Heavy-duty rear terminal block for permanent connections

Compatibility & Integration The LPD421A-FM accommodates standard 19" rack mounting via optional Lambda rack adapters (LRA-1, LRA-2). External overvoltage protection modules (LHOV-4, LHOV-5, LHOV-6) are available for enhanced system protection. Dual outputs support independent or linked operation for voltage multiplication (series) or current expansion (parallel) up to 3.4 A total.