Atec 6220, 6221 User Manual
LOW LEVEL MEASURE & SOURCE
6220
DC Current Source
6221
6220 and 6221
• Source and sink (programmable
load) 100fA to 100mA
14
W output impedance
• 10
ensures stable current sourcing
into variable loads
• 65000-point source memory
allows executing comprehensive
test current sweeps directly
from the current source
• Built-in RS-232, GPIB, Trigger
Link, and digital I/O interfaces
• Reconfigurable triax output
simplifies matching the
application’s guarding
requirements
• Model 220 emulation mode
eliminates need to reprogram
existing applications
6221 O nly
• Source AC currents from 4pA
to 210mA peak to peak for AC
charac ter iza tion of components
and materials. The 6221’s
10MHz output update rate
generates smooth sine waves
up to 100kHz
• Built-in standard and arbitrary
waveform generators with
1mHz to 100kHz frequency
range. Applications include use
as a complex programmable
load or sensor signal and for
noise emulation
• Programmable pulse widths
as short as 5µs, limiting power
dissipation in delicate components. Supports pulsed I-V
measurements down to 50µs
when used with Model 2182A
Nanovoltmeter
• Built-in Ethernet interface for
easy remote control without a
GPIB controller card
AC and DC Current Source
The Model 6220 DC Current Source and Model 6221 AC and DC Current Source combine ease of use
with exceptionally low current noise. Low current sourcing is critical to applications in test environments ranging from R&D to production, especially in the semiconductor, nanotechnology, and superconductor industries. High sourcing accuracy and built-in control functions make the Models 6220
and 6221 ideal for applications like Hall measurements, resistance measurements using delta mode,
pulsed measurements, and differential conductance measurements.
The need for precision, low current sourcing. Device testing and characterization for today’s very
small and power-efficient electronics requires sourcing low current levels, which demands the use of
a precision, low current source. Lower stimulus currents produce lower—and harder to measure—
voltages across the device. Combining the Model 6220 or 6221 with a Model 2182A Nanovoltmeter
makes it possible to address both of these challenges.
AC current source and current source waveform generator. The Model 6221 is the only low
current AC source on the market. Before its introduction, researchers and engineers were forced to
build their own AC current sources. This cost-effective source provides better accuracy, consistency,
reliability, and robustness than “home-made” solutions. The Model 6221 is also the only commercially
available current source waveform generator, which greatly simplifies creating and outputting complex waveforms.
Simple programming. Both current sources are fully programmable via the front panel controls or
from an external controller via RS-232 or GPIB interfaces; the Model 6221 also features an Ethernet
interface for remote control from anywhere there’s an Ethernet connection. Both instruments can
source DC currents from 100fA to 105mA; the Model 6221 can also source AC currents from 4pA to
210mA peak to peak. The output voltage compliance of either source can be set from 0.1V to 105V in
10mV steps. Voltage compliance (which limits
the amount of voltage applied when sourcing
a current) is critical for applications in which
overvoltages could damage the device under
test ( DUT).
Drop-in replacement for the Model 220
current source. These instruments build upon
Keithley’s popular Model 220 Programmable
Current Source; a Model 220 emulation mode
makes it easy to replace a Model 220 with a
Model 6220/6221 in an existing application without rewriting the control code.
Define and execute current ramps easily.
Both the Models 6220 and 6221 offer tools for
defining current ramps and stepping through
predefined sequences of up to 65,536 output
values using a trigger or a timer. Both sources
support linear, logarithmic, and custom sweeps.
APPLICATIONS
• Nanotechnology
– Differential conductance
– Pulsed sourcing and resistance
• Optoelectronics
– Pulsed I-V
• Replacement for AC resistance
bridges (when used with Model
2182A)
– Measuring resistance with
low power
• Replacement for lock-in
amplifiers (when used with
Model 2182A )
– Measuring resistance with
low noise
Precision low current sourcing
1.888.KEITHLEY
www.keithley.com
(U.S. only)
A Greater Measure of Confidence
6220
DC Current Source
6221
Ordering Information
6220 DC Precision Current Source
6221 AC and DC Current Source
6220 /2182A
Complete Delta Mode
System, w/DC Current
Source, Nanovoltmeter,
and all necessary cables
(GPIB cables not included)
6221/2182A
Complete Delta Mode
System, w/AC and DC
Current Source, Nano voltmeter, and all necessary
cables (GPIB cables
not included)
Accessories Supplied
237-ALG-2 6.6 ft (2m), Low Noise,
Precision low current sourcing
8501-2 6.6 ft (2m) Trigger Link
CA-180-3A Ethernet Crossover
CA-351 Communication Cable
CS-1195-2 Safety Interlock
Instruction manual on CD
Getting Started manual (hardcopy)
Software (downloadable)
Input Cable with Triaxto-Alligator Clips
Cable to connect 622x
to 2182A
Cable (6221 only)
between 2182A and 622x
Connector
AC and DC Current Source
The Model 6221’s combination of high source resolution and megahertz update rates makes it capable
of emulating high fidelity current signals that are indistinguishable from analog current ramps.
Free Instrument Control Example Start-up Software
The instrument control example software available for the sources simplifies both performing basic
sourcing tasks and coordinating complex measurement functions with the Keithley Model 2182A. The
software, developed in the LabVIEW
ment guide that helps users set up their instruments and make proper connections, as well as program basic sourcing functions. The advanced tools in the package support delta mode, differential
conductance, and pulse mode measurements. From this package, users can print out the instrument
commands for any of the pre-programmed functions, which provides a starting point for incorporating these functions into customized applications.
Differential Conductance
Differential conductance measurements are among the most important and critical measurements
made on non-linear tunneling devices and on low temperature devices. Mathematically, differential
conductance is the derivative of a device’s I-V curve. The Model 6220 or 6221, combined with the
Model 2182A Nano voltmeter, is the industry’s most complete solution for differential conductance
measurements. Together, these instruments are also the fastest solution available, providing 10× the
speed and significantly lower noise than other options. Data can be obtained in a single measurement pass, rather than by averaging the result of multiple sweeps, which is both time-consuming and
prone to error. The Model 622X and Model 2182A are also easy to use because the combination can
be treated as a single instrument. Their simple connections eliminate the isolation and noise current
problems that plague other solutions.
®
programming environment, includes a step-by-step measure-
ACCESSORIES AVAILABLE
7006-* GPIB Cable with Straight-On Connector
7007-1 Shielded IEEE-488 Cable, 1m (3.3 ft)
7007-2 Shielded IEEE-488 Cable, 2m (6.6 ft)
7078-TRX-5 5 f t (1.5m), Low Noise, Triax-to-Triax Cable
KPCI- 488LPA IEEE-488 Interface/Controller for the PCI Bus
KUSB- 488B IEEE-488 USB-to-GPIB Interface Adapter
(Male on Both Ends)
SERVICES AVAILABLE
6220-3Y-EW 1-year factory warrant y extended to 3 years from
6221-3Y-EW 1-year factory warrant y extended to 3 years from
C/6220-3Y-ISO 3 (ISO-17025 accredited) calibrations within 3
C/6221-3Y-ISO 3 (ISO-17025 accredited) cal ibrations within 3
*Not available in all countries
1.888.KEITHLEY
date of shipment
date of shipment
years of purchase*
years of purchase*
(U.S. only)
LOW LEVEL MEASURE & SOURCE
www.keithley.com
Figure 1. Perform, analyze, and display differential conductance measurements.
Delta Mode
Keithley originally developed the delta mode method for making low noise measurements of voltages
and resistances for use with the Model 2182 Nanovoltmeter and a triggerable external current source.
Essentially, the delta mode automatically triggers the current source to alternate the signal polarity,
then triggers a nanovoltmeter reading at each polarity. This current reversal technique cancels out
any constant thermoelectric offsets, ensuring the results reflect the true value of the voltage.
This same basic technique has been incorporated into the Model 622X and Model 2182A delta
mode, but its implementation has been dramatically enhanced and simplified. The technique can
now cancel thermoelectric offsets that drift over time, produce results in half the time of the previous technique, and allow the source to control and configure the nanovoltmeter, so setting up the
measurement takes just two key presses. The improved cancellation and higher reading rate reduces
measurement noise to as little as 1nV.
A Greater Measure of Confidence
Loading...