Keithley 2260B-30-72 User Manual page 23

CC and CV Mode
CC and CV mode
Description
20
When the power supply is operating in
constant current mode (CC) a constant current
will be supplied to the load. When in constant
current mode the voltage output can vary,
while the current remains constant. When the
load resistance increases to the point where the
current limit (I
SET
the power supply switches to CV mode. The
point where the power supply switches modes
is the crossover point.
When the power supply is operating in CV
mode, a constant voltage will be supplied to
the load, while the current will vary as the load
varies. At the point that the load resistance is
too low to maintain a constant voltage, the
power supply will switch to CC mode and
maintain the set current limit.
The conditions that determine whether the
power supply operates in CC or CV mode
depends on the set current (I
(V ), the load resistance (R
SET
resistance (R ). The critical resistance is
C
determined by V
will operate in CV mode when the load
resistance is greater than the critical resistance.
This means that the voltage output will be
equal to the V
SET
less than I . If the load resistance is reduced
SET
to the point that the current output reaches the
I level, the power supply switches to CC
SET
mode.
2260B Series User Manual
) can no longer be sustained
), the set voltage
SET
) and the critical
L
/I . The power supply
SET SET
voltage but the current will be