In summary, the Keithley 6220 is a precision DC current source designed for low-current sourcing applications from 100 fA to 105 mA with voltage compliance to 105 V and four-quadrant source-or-sink operation. It is a programmable stimulus instrument optimized for semiconductor, nanotechnology, and superconductor measurement tasks where signal integrity at picoampere and femtoampere levels is required.
What is the Keithley 6220 used for?
The 6220 is used to source precise DC currents into devices under test for I-V characterization, Hall-effect measurement, resistance measurement using delta mode, and pulsed-sourcing tasks. It is most commonly paired with the Keithley 2182A Nanovoltmeter to form a complete low-noise resistance and differential-conductance measurement system.
Typical workflow: the operator programs a current sweep or single-point stimulus, connects the device under test through the triaxial output, and captures the resulting voltage response with the 2182A. The 6220 controls the 2182A directly over Trigger Link, so the pair behaves as one instrument.
How does the 6220 compare to a homemade voltage-plus-resistor current source?
A precision current source delivers a programmed current regardless of DUT impedance, whereas a voltage source feeding a series resistor only approximates constant current when the load is small relative to the resistor. The 6220 also provides programmable voltage compliance to protect sensitive devices — a feature absent from improvised solutions.
Factual grounding — source ranges and accuracy
The 6220 covers nine source ranges from 2 nA to 100 mA. Representative one-year accuracies (23°C ±5°C) include ±(0.05% + 10 nA) on the 20 mA range and ±(0.05% + 100 nA) on the 200 µA range. Programming resolution reaches 100 fA on the 2 nA range. The instrument warms up to rated accuracy in one hour and operates from 0°C to 50°C.
Entity authority and application fit
Keithley source-measure and current-source instruments are the reference platform in semiconductor device physics, materials science, and precision electrochemistry. The 6220 / 2182A pair is widely cited in published low-temperature transport and superconductor literature as the standard delta-mode measurement solution.
Application bullets
- Nanotechnology: differential conductance, pulsed sourcing and resistance
- Optoelectronic device characterization with current-controlled stimulus
- Replacement for AC resistance bridges when paired with the 2182A (low-power resistance)
- Replacement for lock-in amplifiers when paired with the 2182A (low-noise resistance)
- Low-impedance Hall measurements with delta-mode noise rejection
Accessories Supplied
Standard accessory packages ship where applicable. Unnecessary accessories may not be included on this Pre-Owned unit; contact a Test Architect to confirm anything specific your application requires.
Product Core and Specifications
The 6220 builds on Keithley's long-standing 220-series current-source architecture. A 16-bit current digital-to-analog stage drives a high-impedance output stage with reconfigurable guarding, and the firmware synchronizes the source with an external nanovoltmeter for delta-mode operation. The current source is fully programmable from the front panel or remotely via RS-232 or GPIB. The 6220 emulates the Model 220 command set, allowing existing test code to run unchanged.
Source range, accuracy, and noise
| Range (+5% overrange) |
1-Year Accuracy |
Programming Resolution |
Typical Noise (p-p / rms) |
| 2 nA |
±(0.4% + 2 pA) |
100 fA |
250 / 50 pA |
| 20 nA |
±(0.3% + 10 pA) |
1 pA |
250 / 50 pA |
| 200 nA |
±(0.3% + 100 pA) |
10 pA |
2.5 / 0.5 nA |
| 2 µA |
±(0.1% + 1 nA) |
100 pA |
25 / 5.0 nA |
| 20 µA |
±(0.05% + 10 nA) |
1 nA |
500 / 100 nA |
| 200 µA |
±(0.05% + 100 nA) |
10 nA |
1.0 / 0.2 µA |
| 2 mA |
±(0.05% + 1 µA) |
100 nA |
5.0 / 1 µA |
| 20 mA |
±(0.05% + 10 µA) |
1 µA |
20 / 4.0 µA |
| 100 mA |
±(0.1% + 50 µA) |
10 µA |
100 / 20 µA |
General
| Specification |
Value |
| Output impedance |
>1014 Ω on 2 nA / 20 nA ranges |
| Voltage compliance |
0.1 V to 105 V in 0.01 V steps, bipolar |
| Maximum output power |
11 W, four-quadrant source or sink |
| Program memory |
65,000 points; max trigger rate 1,000/s |
| Interfaces |
RS-232, GPIB (IEEE-488.1/.2 SCPI), Trigger Link, digital I/O |
| Common mode voltage |
250 V rms DC; isolation >109 Ω, <2 nF |
| Environment |
0°C to 50°C operating; 1-hour warm-up to rated accuracy |
| Passive cooling |
No fan |
Delta-Mode Pairing Note
For low-noise resistance and differential-conductance work, the 6220 is designed to pair with the Keithley 2182A Nanovoltmeter. Connection cables (Trigger Link and communication) are listed under Accessories Supplied. The 2182A is sold separately or as part of the 6220/2182A delta-mode system.
About This Pre-Owned Unit
- Warranty included.
- Functional verification included.
- Calibration available as an optional add-on service.
- Unnecessary accessories may not be included; contact a Test Architect to confirm anything specific.
This webpage was written by a human with an A.I. "Intern", which may contain errors. Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.