Flash Connection Guidelines; Programming And Erasing Flash Memory - Keithley 4200A-SCS User Manual

Model 4200A-SCS Pulse Card (PGU and PMU) User's Manual

Flash connection guidelines

All interconnects on instrument chassis are white SMA cables. Cables from the instrument to device
are BNC coaxial, except for the direct SMU4 connection, which is black triaxial. Use triaxial to BNC
adapters (if necessary) to connect to probe manipulators.
The trigger interconnects are white SMA cables. Cables from the instrument to device are BNC
coaxial for the pulse card channels and triaxial for the SMUs. Use triaxial to BNC adapters (if
necessary) to connect to probe manipulators.
To test on-wafer devices, there are various ways to connect the SMA cables to the probe
manipulators. For the direct connect method or switch method, adapters convert the BNC cabling to
the triaxial connector to be compatible with many types of probe manipulators.
Use the supplied torque wrench to tighten each connection as it is assembled. Always connect and
torque adapter/cable assemblies before attaching the assembly to the instrument cards.
Non-axial stress on the bulkhead connectors on the SMU or pulse cards could cause damage
to the cards installed in the 4200A-SCS chassis. Pre-torque the connections to prevent
this damage.
To remove the LEMO triaxial-to-SMA adapter from a SMU, pull on the knurled silver portion of the
connector to release the latches from the SMU connector.
Failure to fully disengage the LEMO adapter latches may result in damage to the adapter and
the SMU.

Programming and erasing flash memory

A floating gate (FG) transistor is a modified field-effect transistor with an additional floating gate. The
FG transistor is the basic storage structure for data in nonvolatile memory. The floating gate stores
charge, which represents data in memory.
The control gate (CG) reads, programs, and erases the FG transistor. The presence of charge on the
gate shifts the voltage threshold (V
4200A-PMU-900-01 Rev. A December 2020
) to a higher voltage, as shown in the following figure.
T
Section 8: Testing flash memory
8-3