Keithley 2520, User Manual, Page: 70 / 329

3-10 Basic Operation Model 2520 User’s Manual
Configuring laser diode source
The basic procedure for setting up laser diode current source values for both DC and pulse
modes is outlined below.
DC mode
1. Press CONFIG then LASER I
L
to access the source configuration menu.
2. Choose POLARITY, then press ENTER.
3. Select POSITIVE or NEGATIVE as desired, then press ENTER. (See Figure 3-2
for a comparison of positive and negative source polarity.)
4. Select SHAPE, then press ENTER.
5. Choose DC, then press ENTER.
6. Press EXIT to return to normal display.
7. Press the LASER I
L
key, then the EDIT key so the blinking cursor is in the I
L
source display field.
8. While in the edit mode, use the RANGE ▲ and
▼
keys to select the desired source
range (500mA or 5A). Use the lowest range possible for best accuracy.
9. To simply increment or decrement the displayed source value, use the EDIT and
keys to place the blinking cursor on the digit to be changed, then increment or
decrement the value with the EDIT ▲ and
▼
keys. Note that the source value will
be updated immediately; you need not press ENTER to complete the process, but
you can press ENTER to exit the edit mode immediately.
10. To enter the source value directly, simply key in the desired value with the numeric
keys while the cursor is blinking. Again, the source value will be updated immedi-
ately.
11. Press the COMPL key, then set the voltage compliance (limit) to the desired value.
Press ENTER to complete your selection and return to normal display.
▲
▲