Keithley 2601B Reference Manual page 202

Series 2600B System SourceMeter® Instrument Reference Manual
Understanding source settling times
Each Series 2600B source-measure unit (SMU) can drive up to 50 µF of a capacitance in
high-capacitance mode. In order to accomplish this, the speed of the Series 2600B SMU is reduced.
Source settling times increase when high-capacitance mode is enabled. The following tables
compare the source settling times in normal and high-capacitance modes.
Model 2601B/2602B/2604B source settling times
Range
100 mV
1 V
6 V
40 V
Model 2611B/2612B/2614B/2634B/2635B/2636B source
settling times
Range
200 mV
2 V
20 V
200 V
In high-capacitance mode, the frequency compensation capacitance across the measure range
resistors increases. This increase leads to longer settling times on some current measure ranges.
The same range elements that are used to measure current are used to source current. Therefore,
the current limit response times will respond in a similar manner.
Current measure and source settling times
Current measure range
1 A - 1.5 A
(2611B/2612B/2614B/2634B/2635B/2636B)
1 A - 3 A (2601B/2602B/2604B)
100 mA
10 mA
1 mA
100 µA
10 µA
1 µA
When high-capacitance mode is enabled, the amount of time to change the current measure range
increases for each SMU. The current measure range and the current limit range are locked together.
Setting the current limit automatically updates the measure range.
2600BS-901-01 Rev. B / May 2013
Normal mode High capacitance mode
50 µs 200 µs
50 µs 200 µs
100 µs 200 µs
150 µs
7 ms
Normal mode High capacitance mode
50 µs 600 µs
50 µs 600 µs
110 µs
1.5 ms
700 µs
20 ms
Normal mode High capacitance mode (typical)
(typical)
120 µs 120 µs (Rload > 6 Ω)
80 µs 120 µs (Rload > 2 Ω)
100 µs 100 µs
80 µs 100 µs
100 µs
3 ms
150 µs
3 ms
500 µs
230 ms
2 ms 230 ms
Section 3: Functions and features
3-67