08 | Keysight | Low Current Semiconductor Measurements
Using the B2980A Series Ammeter - Technical Overview
Example 1. Monitoring LED Forward diode current
(continued)
Step 4. Press the [Run/Stop] key to start continuous current measurements. The “AUTO” indicator at the bottom of the screen shows
that the measurement is continuously repeating.
Note: If you press the [Single] key, then only one measurement will be made. The “ARM” indicator is shown while measurements are in progress.
Step 5. Change the voltage source to edit mode using the procedure outlined in step 2. (B2985A/87A only).
Then change the voltage to approximately 1.0 V.
Step 6. (1) Continue rotating the [Knob] and increasing the voltage until the current is between 10 to 20 mA.
Note: If using the B2981A/83A then increase the external voltage source voltage.
(2) The LED starts to emit light at around 1.5 V.
(3) The LED current will continue to increase until the LED temperature stabilizes.
Roll View shows the measurement history
Rotate slowly to increase the voltage. The
value increases as you rotate the [knob] clockwise.
Stop when the voltage reaches approximately 1.0 V.
(3) Roll View shows the current drift status after the
LED’s temperature stabilizes.
(1) Further rotate , and increase the voltage until
the current is between 10 to 20 mA.
(2) LED light up as
shown in the picture.
As the LED
heats up the
current drifts.
