Keithley 2520, User Manual, Page: 57 / 329

Model 2520 User’s Manual Connections 2-7
Figure 2-4
Remote interlock connections
Key interlock
The key must be inserted into KEY INTERLOCK and rotated to the ENABLED position
to operate the unit. Rotate the key to the DISABLED position and remove the key to
inhibit the source outputs.
Laser diode test connections
Connecting cables
For optimum performance, use only the supplied connecting cables or the equivalent. Be
sure the connector insulating boots are in place and properly seated to assure ESD (elec-
tro-static discharge) protection.
Typical connections
Figure 2-5 shows typical connections to the laser diode, the back detector photodiode, and
the front detector photodiode in a laser diode test setup (interlock connections are not
shown; see
Figure 2-4 ). Connections are as follows:
• The center conductors of the CURRENT OUTPUT and VOLTAGE SENSE HI and
LO terminals connect to the laser diode under test. Current is applied to the laser
diode through the CURRENT OUTPUT HI and LO terminals, and voltage across
the DUT is measured through the VOLTAGE SENSE HI and LO terminals.
• DETECTOR 1 connects to the forward detector photodiode. The CURRENT
INPUT (center conductor) is connected to one photodiode terminal while the BIAS
terminal (inner shield) is connected to the other photodiode terminal.
• DETECTOR 2 connects to the back detector photodiode. The CURRENT INPUT
(center conductor) is connected to one photodiode terminal while the BIAS termi-
nal (inner shield) is connected to the other photodiode terminal.
NOTE The BNC cable shields should be connected as shown if possible. If one terminal
of the laser diode is to be earth grounded, it must be the anode.
Pin 9
Pin 1
1 9
DISABLED
REMOTE
INTERLOCK
ENABLED