Atec Keithley-6220-6221 - Manual (Page 2)

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www.keithley.com
1.888.KEITHLEY
(U.S. only)
A Greater Measure of Confidence
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 ® programming environment, includes a step-by-step measure-
ment guide that helps users set up their instruments and make proper connections, as well as pro-
gram 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 incorporat-
ing 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 measure-
ment 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 .
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 previ-
ous 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 .
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 volt-
meter, and all necessary
cables (GPIb cables
not included)
accessories supplied
237-alG-2 6.6 ft (2m), low Noise,
Input Cable with Triax-
to-alligator Clips
8501-2 6.6 ft (2m) Trigger link
Cable to connect 622x
to 2182a
Ca-180-3a Ethernet Crossover
Cable (6221 only)
Ca-351 Communication Cable
between 2182a and 622x
Cs-1195-2 safety Interlock
Connector
Instruction manual on CD
Getting started manual (hardcopy)
software (downloadable)
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 ft (1 .5m), Low Noise, Triax-to-Triax Cable
(Male on Both Ends)
KPCI-488LPA IEEE-488 Interface/Controller for the PCI Bus
KUSB-488B IEEE-488 USB-to-GPIB Interface Adapter
sErVICEs aVaIlablE
6220-3Y-EW 1-year factory warranty extended to 3 years from
date of shipment
6221-3Y-EW 1-year factory warranty extended to 3 years from
date of shipment
C/6220-3Y-ISO 3 (ISO-17025 accredited) calibrations within 3
years of purchase*
C/6221-3Y-ISO 3 (ISO-17025 accredited) calibrations within 3
years of purchase*
*Not available in all countries
6220
6221
DC Current Source
AC and DC Current Source
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