Agilent / Keysight 87421A Power Supply, 12 VDC, 15 VDC, 25 W

The Keysight 87421A is a universal input DC switching power supply engineered to deliver bias voltages for microwave system amplifiers and high-speed lightwave converters. This compact 25 W unit operates from 90–250 VAC (50/60 Hz) input and provides +12 VDC at 2.0 A primary output with a -12 VDC at 200 mA secondary output. Weighing just 0.9 kg, it integrates into bench and rack-mounted configurations through its included 2-meter DC bias cable terminated with a 3-pin connector and D-subminiature connector (83006-60005) for direct amplifier interface.

Technical Specifications

• Primary Output: +12 VDC at 2.0 A


• Secondary Output: –12 VDC at 200 mA


• Maximum Output Power: 25 W


• AC Input: Universal, 90–250 VAC, 50/60 Hz


• Line Regulation: 0.1%


• Load Regulation (20% to full load): 2.0%


• Output Ripple: 25 mV RMS max


• Output Noise: 2% peak to peak max


• Operating Temperature: 0° to +55° C (full load)


• Storage Temperature: –40° to +70° C


• Dimensions & Weight: 0.9 kg; see operating manual for mechanical dimensions

Key Features

• Overvoltage protection with automatic recovery from short circuit and overload conditions


• Low output ripple and noise for sensitive bias applications


• Tight line and load regulation across operating range


• Compact form factor suitable for system integration or standalone benchtop operation


• 2-meter interconnect cable included for remote amplifier placement

Typical Applications Bias supply for microwave system amplifiers and high-speed lightwave measurement modules requiring dual-rail DC bias with minimal ripple and thermal management in laboratory and field environments.

Compatibility & Integration Designed for use with Keysight 83006A, 83017A, 83018A, 83050A, 83051A, 87415A microwave amplifiers and 83440C high-speed lightwave converter (with 83440-60009 adapter).