Keithley 248 HV DC Power Supply, 5 kV, 5 mA

The Keithley 248 is a programmable high-voltage DC power supply engineered for precision sourcing in research, component testing, and material characterization. It delivers 0 to ±5000 V DC at up to 5.000 mA DC with 25 W maximum power and exceptional output stability. The supply features reversible polarity, voltage set accuracy of ±(0.01% of setting + 2.5 V), and load regulation of 0.005% typical across a 100% load change.

Output ripple is held to <0.002% of full scale without filtering, with two selectable filter options available to further reduce noise

Filter 1 supports operation to 3000 V DC at 5 mA, while Filter 2 extends to the full 5000 V DC at 3 mA. Voltage settles to 99.9% of programmed value within 3 seconds, and complete discharge occurs within 6 seconds. Current compliance is programmable with 0.01% + 2.5 µA accuracy and 1 µA resolution.

The compact half-rack design measures 89 mm × 206 mm × 406 mm and weighs 3.7 kg, featuring an SHV male output connector on the rear panel. GPIB (IEEE-488.1) remote interface enables automated control, while external voltage setting and analog monitor outputs (both 0 to +10 V for full-range scaling) support integration with external measurement systems. Operating temperature range is 0°C to 50°C with 1-hour warm-up time.

Input power requirement is 55 watts at 100, 120, 220, or 240 V AC ±10%, 50 or 60 Hz.

Technical Specifications

• Output voltage: 0 to ±5000 V DC


• Maximum output current: 5.000 mA DC


• Maximum power: 25 W


• Voltage set accuracy: ±(0.01% of setting + 2.5 V)


• Voltage display accuracy: ±1 V typical, ±2 V maximum


• Voltage resolution: 1 V


• Line regulation: 0.001% for ±10% line voltage change


• Load regulation: 0.005% typical for 100% load change


• Output ripple (10 Hz–100 kHz): <0.002% of full scale maximum without filter


• Settling time (0 to programmed voltage): Within 3 seconds to 99.9% final value


• Discharge time (to within 50 V of zero): Within 6 seconds, no load


• Current limit accuracy: 0.01% + 2.5 µA


• Current resolution: 1 µA


• Current display accuracy: ±1 µA typical, ±2 µA maximum

Key Features

• Reversible polarity (positive or negative output)


• Dual selectable output filters for ripple reduction


• GPIB (IEEE-488.1) remote control interface


• External voltage set input (0 to +10 V, 1 MΩ impedance, ±0.2% accuracy at 16 Hz update)


• Monitor output (0 to +10 V, <1 Ω impedance, ±0.2% accuracy at 8 Hz update)


• Programmable current trip


• SHV male rear-panel connector


• Compact half-rack form factor

Typical Applications High-voltage research, semiconductor component testing, material characterization, and precision voltage sourcing requiring low ripple and excellent regulation.

Compatibility & Integration GPIB interface enables integration with automated test systems and measurement suites. Analog monitor and external set inputs accommodate analog control loops and direct measurement integration. Operating range 0°C to 50°C supports laboratory and controlled industrial environments.