6487 Picoammeter/ Voltage Source0 pages

The 5½-digit Model 6487 Picoammeter/Voltage
Source improves on the measurement capability
of the award-winning Model 6485, and adds a
high resolution 500V source. It provides higher
accuracy and faster rise times than the 6485, as
well as a damping function for use with capacitive devices. With eight current measurement
ranges and high speed autoranging, this costeffective instrument can measure currents from
m
20fA to 20mA, take measure­ ents at speeds up
to 1000 readings per second, and source voltage
­
from 200µV to 505V.

•t 10fA resolution
•t 5½-digit resolution
•t <200µV burden voltage
•t Alternating Voltage method
ohms measurements
•t Automated voltage sweeps for
I-V characterization
•t Floating measurements up to
500V
•t Up to 1000 readings/second
•t Built-in Model 486 and 487
emulation mode
•t IEEE-488 and RS-232 interfaces
•t Analog output
•t Digital I/O

The Model 6487’s 10fA resolution, superior sensitivity, voltage sweeping, and Alternating Voltage
resistance measurements make it well suited for
characterizing low current devices. Using the
latest current measurement technology, it is significantly less expensive than other instruments
p
that ­ erform similar functions, such as optical
power meters, tera-ohmmeters, competitive
picoammeters, or user-designed solutions. With
a price that’s comparable to a high-end DMM, the Model 6487 makes picoamp-level measurements
affordable for virtually any laboratory or production floor.
Low Voltage Burden and Higher Accuracy
While DMMs typically employ shunt ammeter circuitry to measure current, the Model 6487 is a feedback picoammeter. This design reduces voltage burden by several orders of magnitude, resulting in a
voltage burden of less than 200µV on the lower measurement ranges. The low voltage burden makes
the Model 6487 function much more like an ideal ammeter than a DMM, so it can make current
measurements with high accuracy, even in circuits with very low source voltages.
Successor to the Model 487
The Model 6487 builds on the strengths of
one of Keithley’s most popular picoammeters,
the Model 487, offering an additional 20mA
measurement range, as well as much higher
measurement speeds, up to 1000 readings per
second. It simplifies device characterization
with built-in voltage sweeping capability and the
Alternating Voltage method for high resistances.
A time-stamped 3000-reading data buffer provides minimum, maximum, and standard deviation statistics. A built-in emulation mode makes
it possible to control the Model 6487 with any
custom code written to control the Model 487.

Current Ranges

Model 487
2 nA–2 mA

Voltage Burden

200 µV

Reading Rate
Voltage Sweeps
Alternating Voltage
Ohms
Analog Output
Storage Buffer
Best V Source
Resolution

Up to 180/s
No

Model 6487
2 nA–20 mA
200 µV (1 mV on
20 mA range)
Up to 1000/s
Yes

No

Yes

Yes
(non-inverting)
512 points

Yes
(inverting)
3000 points

1 mV

0.2 mV

Features that Expand Test and Measurement Flexibility
•t Direct resistance measurements. Optimized for resistances from 50W to 5×1014W using the
Source Voltage/Measure Current method.
•t Alternating Voltage method resistance measurements. This method improves resistance
measurements on devices with high background current or high noise. It extends the measurable
resistance range up to 1016W.
•t 500V overload protection. This high overload protection and a robust design let the Model
6487 tolerate abusive overflows, including accidentally shorting the voltage source directly into
­
the ammeter.

1.888.KEITHLEY (U.S. only)
www.keithley.com
A Greater Measure of Confidence

Measures low currents and high resistances quickly, accurately, and economically

Picoammeter/ Voltage Source

LOW LEVEL MEASURE & SOURCE

Measures low currents and high resistances quickly, accurately, and economically

6487