06 | Keysight | Low Current Semiconductor Measurements
Using the B2980A Series Ammeter - Technical Overview
4. Histogram View enables real-time data distribution analysis
(continued)
This example shows how you can use line frequency averaging and data iltering in
conjunction with the Histogram View to improve data quality
Note: The sample histogram shown in Figure 4(a), which has a bimodal distribution with peaks at both
ends, is typical of the situation where sinusoidal power line voltage is the main noise source. Figure 4(b)
illustrates that the line frequency noise components can be iltered out using power line cycle integra
-
tion and data averaging.
Low Current Measurement Example
Measurement steps on B2985A/87A front panel operation
This section gives step-by-step instructions on how to use the B2980A’s Femto/Picoam-
meter to perform low current (I/V) characterization using an LED as the test device. The
B2985A Electrometer/High Resistance Meter is used in the example because it has a
built-in voltage source so that no additional external instruments are required to apply
voltage to the LED.
Note: To make the same measurements using the B2981A/B2983A Femto/
Picoammeter requires some modiications to the software key sequences and
steps shown in this example (although the ammeter setup is identical).
Of course, when using the B2981A/B2983A you need to supply an external
voltage source to measure the I/V characteristics.
You can download the test setup of the following examples from the
next link; www.keysight.com/ind/SensitiveMeasurements
Example 1. Monitoring LED Forward diode current
Figure 5 shows the proper connections to measure the I/V charac-
teristics of an LED. Note that it is important to connect the ammeter
common to the chassis ground using the banana to lug cable as
shown in the igure.
Note: If the ammeter common and the test ixture shield are connected,
then this ground connection is not necessary.
(a) 0.1 PLC speed measurement.
(b) Normal speed measurement using the data averaging.
Measurement condition:
- Speed: 0.1 PLC
- Filtering: None
Measurement condition:
- Speed: Normal
- Filtering: Moving average (100 points)
9.5X improvement
in noise distribution
Figure 4. Using histogram view and other functions to improve measurement data.
A
A
+
+
Vs
Vs High
Ammeter
Common
LED
Test Fixture (N1295A)
J1
B2980A Series
Triax cable
Connect with the
Banana to lug cable
Chassis ground
Vs Low
N1254A-101
adapter
Coax
cable
adapter
Figure 5. LED I/V measurement setup example.