Keithley 2657A User Manual

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 4: Theory of operation
2657A-901-01 Rev. B/December 2012 4-17
Make sure to take into account that reversing the polarity may destroy some power sources. To
prevent a negative charge, monitor the SMU’s measurement of the battery voltage and stop the
discharge before the the Model 2657A starts to operate in quadrant III (negative voltage). You can
stop the discharge by changing the programmed current source level or by disconnecting the SMU
from the device.
In the following figure, as the battery drains, the battery voltage is lowered as shown by the green
arrow. Operation will continue in this direction until the user stops operation or the voltage reaches
the voltage compliance limit line.
Since the battery is a power source, operation in this example is limited by the capability of the
battery to deliver 50 mA (see the following figure).
Figure 83: Considerations when sourcing current and sinking power
NOTE
Programmed current source value:
-50 mA
Programmed voltage compliance value:
±1500 V
-50 mA +50 mA-100 mA +100 mA
Voltage
compliance
limit lines
Initial
battery
voltage
Battery
voltage during
discharge
Stop discharge
before source
becomes negative
Programmed current
source value line
(IV)
Sink
(I)
Source
(II)
Sink
(III)
Source
0 V
+1000 V
+500 V
-500 V
-1000 V
-1500 V
+1500 V

Keithley 2657A Specifications

General

Brand	Keithley
Model	2657A
Category	Measuring Instruments
Language	English