The Keithley 228 Programmable Voltage/Current Source delivers precision voltage and current outputs for automated test equipment and laboratory calibration environments. This dual-function source offers continuously adjustable voltage (0 V to 20 V) and current (0 mA to 500 mA) with 10 mV and 0.1 mA resolution respectively. Programmatic control via IEEE-488 GPIB and SCPI-compatible commands enables integration into test systems requiring repeatable, high-accuracy sourcing.
Technical Specifications
Voltage Output
• Range: 0 V to 20 V
• Resolution: 10 mV
• Accuracy: ±0.1% of setting ± 5 mV
• Stability (8-hour warm-up): ≤0.01% of setting ± 2 mV
• Temperature Coefficient: ≤0.01% of setting ± 1 mV / °C
Current Output
• Range: 0 mA to 500 mA
• Resolution: 0.1 mA
• Accuracy: ±0.1% of setting ± 0.5 mA
• Stability (8-hour warm-up): ≤0.01% of setting ± 0.5 mA
• Temperature Coefficient: ≤0.01% of setting ± 0.5 mA / °C
Output Characteristics
• Maximum Power: 10 W
• Output Impedance: <0.1 Ω
• 4-wire Kelvin sensing for precise load voltage measurement
• Programmable current limiting
• Voltage Noise (10 Hz to 10 MHz): <1 mV RMS
• Current Noise (10 Hz to 10 MHz): <0.5 mA RMS
Power & Environmental
• Line Voltage: Selectable 100/120/220/240 VAC ±10%
• Line Frequency: 47 Hz to 63 Hz
• Power Consumption: Approximately 150 VA maximum
• Dimensions: 89 mm × 213 mm × 356 mm
• Weight: 5.0 kg
• Cooling: Forced air
– Key Features
• IEEE-488 GPIB interface with SCPI compatibility for remote automation
• Local and remote programming modes
• Banana jack and 5-way binding post output terminals
• Separate Kelvin sense terminals for accurate voltage measurement at the device under test
– Typical Applications
Automated test equipment systems, component calibration, precision device characterization, and laboratory measurement environments requiring stable, programmable voltage or current sourcing.
– Compatibility & Integration
Integrates with standard GPIB controllers and test executive software. Supports both local front-panel control and remote instrument programming.
