The Keithley 220 Programmable Current Source is a precision DC current sourcing instrument designed for laboratory and automated test system (ATE) environments requiring stable, accurate current delivery across a wide dynamic range. It delivers programmable current from ±0.5 pA to ±101 mA with selectable ranges (±100 mA, ±20 mA, ±2 mA) and voltage compliance from ±1 V to ±105 V in 1 V steps. The instrument combines low output impedance exceeding 10¹⁴ Ω on the 1 nA range with response times under 3 ms, making it suitable for device characterization, materials research, and component testing where precise current control is essential.
## Technical Specifications
**Current Output**
• Range: ±0.5 pA to ±101 mA DC
• Selectable current limits: ±100 mA, ±20 mA, ±2 mA (–0, +20%)
• Output impedance: >10¹⁴ Ω (1 nA range)
• Output capacitance: <20 pF
• Response time: <3 ms to within 0.1% of programmed change
**Voltage Compliance**
• Programmable range: ±1 V to ±105 V in 1 V steps
• Transient recovery: <3 ms to rated accuracy after compliance voltage change
• Bipolar voltage limit: Yes
**Accuracy and Stability**
• Output stability: ±(0.05% of setting + 0.05% of range)/hour
• Load regulation: ±(0.05% + 50 µA)/V
• Line regulation: <0.01% for AC power line changes
• Temperature coefficient: 100 ppm/°C (most ranges)
**Noise Characteristics**
• 100 mA range (0.1 Hz to 30 kHz): (150 µV + 50 ppm range) p-p
• 1 nA range (0.1 Hz to 10 Hz): 500 fA p-p
• Broadband (0.1 Hz to 300 kHz): 5 mV p-p
## Key Features
• 100-step programmable memory buffer with dwell times from 3 ms to 999.9 s
• Dwell time accuracy: ±(0.05% + 200 µs)
• Guard output with ±1 mV accuracy (excluding lead voltage drop)
• Rear panel selectable REMOTE and LOCAL sensing modes
• Maximum lead drop per lead: 0.5 V
## Typical Applications
Device characterization, materials research, component testing, precision current injection, and leakage current measurements in demanding laboratory and production test environments.
## Compatibility & Integration
IEEE-488 (GPIB) interface. TTL-compatible external trigger input/output. Four programmable digital I/O lines (input and output). Power supply: 105–125 V or 210–250 V AC (internal selection), 50 or 60 Hz.
