Enabling High-Capacitance Mode - Keithley 2651A Reference Manual

Section 3: Functions and features

Enabling high-capacitance mode

Before enabling high-capacitance mode, note the following:
•
It is important to read the previous section to understand the impact of high-capacitance mode.
•
Test the DUT and the capacitor to determine the best current source and range of output voltages.
• The settling times can vary based on the DUT. It is important to test the limits of the DUT before you
use high-capacitance mode.
•
Failure to test the DUT for the appropriate current source and output voltages can result in damage to or
destruction of the DUT.
•
For optimal performance, do not continuously switch between normal mode and high-capacitance
mode.
•
Before you charge the capacitor, start with 0 (zero) voltage across the capacitor.
•
When high-capacitance mode is enabled, a minimum load capacitance of 100 nF is recommended. In
absence of this minimum load capacitance, overshoot and/or ringing may occur.
Front panel
To enable high-capacitance mode from the front panel:
1. Press the CONFIG key, then select SRC > HIGHC-MODE.
2. Select SRC-ENABLE > ENABLE. High-capacitance mode is enabled.
3. Push the ENTER key.
4. Press the EXIT (LOCAL) key to back out of the menu structure.
Command interface
Turning on High-C mode has the following effects on the SMU settings:
•
smua.measure.autorangei is set to smua.AUTORANGE_FOLLOW_LIMIT and cannot be
changed.
•
Current ranges below 1 μA are not accessible.
•
If smua.source.limiti is less than 1 μA, it is raised to 1 μA.
•
If smua.source.rangei is less than 1 μA, it is raised to 1 μA.
•
If smua.source.lowrangei is less than 1 μA, it is raised to 1 μA.
•
If smua.measure.lowrangei is less than 1 μA, it is raised to 1 μA.
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Model 2651A High Power System SourceMeter® Instrument Reference Manual
2651A-901-01 Rev. A / March 2011