Datasheet

ManualsBrandsKEITHLEY ManualsTest & MeasurementBench multimeter

LOW LEVEL MEASURE & SOURCE

A Greater Measure of Conﬁdence

www.keithley.com

1.888.KEITHLEY

(U.S. only)

• 10fA resolution

• 5½-digit resolution

• <200µV burden voltage

• Alternating Voltage method

ohms measurements

• Automated voltage sweeps for

I-V characterization

• Floating measurements up to

500V

• Up to 1000 readings/second

• Built-in Model 486 and 487

emulation mode

• IEEE-488 and RS-232 interfaces

• Analog output

• Digital I/O

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 capaci-

tive devices. With eight current measurement

ranges and high speed autoranging, this cost-

effective instrument can measure currents from

20fA to 20mA, take measure ments at speeds up

to 1000 readings per second, and source voltage

from 200µV to 505V.

The Model 6487’s 10fA resolution, superior sen-

sitivity, voltage sweeping, and Alternating Voltage

resistance measurements make it well suited for

characterizing low current devices. Using the

latest current measurement technology, it is sig-

nificantly less expensive than other instruments

that perform 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 feed-

back 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 pro-

vides minimum, maximum, and standard devia-

tion statistics. A built-in emulation mode makes

it possible to control the Model 6487 with any

custom code written to control the Model 487.

Features that Expand Test and Measurement Flexibility

• Direct resistance measurements. Optimized for resistances from 50W to 5×10

W using the

Source Voltage/Measure Current method.

• 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 10

• 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.

Model 487 Model 6487

Current Ranges 2 nA–2 mA 2 nA–20 mA

Voltage Burden 200 µV

200 µV (1 mV on

20 mA range)

Reading Rate Up to 180/s Up to 1000/s

Voltage Sweeps No Yes

Alternating Voltage

Ohms

No Yes

Analog Output

Yes

(non-inverting)

Yes

(inverting)

Storage Buffer 512 points 3000 points

Best V Source

Resolution

1 mV 0.2 mV

6487

Picoammeter/ Voltage Source

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

Summary of content (4 pages)

PAGE 1
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.
PAGE 2
Ordering Information 6487 Picoammeter/ Voltage Source Accessories Supplied CA-186-1B Ground Connection Cable, Banana to Screw-Lug CAP-31 Protective Shield/ Cap (3-lug) CS-459 Safety Interlock Plug 7078-TRX-3 Low Noise Triax Input Cable, 1m (3 ft) 8607 High Voltage Banana Cable Set for Voltage Source Output APPLICATIONS • Resistance/resistivity measurements Picoammeter/ Voltage Source • Rear panel triax input. This allows the picoammeter to be used in floating operation, up to 500V.
PAGE 3
Monitoring and Control of Focused Ion Beam Currents In semiconductor fabrication, focused ion beam systems are often used for nanometer-scale imaging, micromachining, and mapping. Careful monitoring of the magnitude of the beam current with an ion detector is critical. The ion detector generates a secondary current that’s proportional to the current of the primary ion beam. When this secondary current is measured, it can be used to control the intensity of the primary beam.
PAGE 4
Picoammeter/ Voltage Source Model 6487 specifications Typical Analog 5½ Digit Accuracy (1 Year) 1 Rise Time (10% to 90%) 3 Default ±(% rdg. + offset) Typical Damping4 Range Resolution 18°–28°C, 0–70% RH RMS Noise 2 Off On 2 nA 10 fA 0.3 % + 400 fA 20 fA 4 ms 80 ms 20 nA 100 fA 0.2 % + 1 pA 20 fA 4 ms 80 ms 200 nA 1 pA 0.15% + 10 pA 1 pA 300 µs 1 ms 2 µA 10 pA 0.15% + 100 pA 1 pA 300 µs 1 ms 20 µA 100 pA 0.1 % + 1 nA 100 pA 110 µs 110 µs 200 µA 1 nA 0.1 % + 10 nA 100 pA 110 µs 110 µs 2 mA 10 nA 0.