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.
