
INPUT/OUTPUT CELLS
OVERVIEW
Samsung ASIC
4-1
STD150
OVERVIEW
This chapter describes the Input/Output cells (2.5V/ 3.3V drive and 5V-tolerant), power/ground and ESD slot
cells in the STD150 library.
The switching characteristics of each cell follow the table of switching characteristics of the cell. The AC
characteristics of bi-directional buffers are not included in this data sheet. However, they are the same as
the component input and output buffers that make up the bi-directional buffer.
There are many possible combinations of input/output cells, therefore, the naming convention is adopted
to help efficiently identify the cell and its characteristics from its name (refer to the naming conventions
contained in “Summary Tables” section.)
The “Summary Tables” section shows the list of 2.5V/3.3V drive and 5V-tolerant I/O cells by
category (input, output, bi-directional, etc.). Moreover, each section begins with a table containing a brief
functional description of each cell in that section.
NOTE:
When both A and B driving signals do not exist, SEC tolerant IO’s pad voltage goes high state. However, those
5V tolerant input and bi-directional cells with 100k
pull-up resistor have NMOS pass transistor like Figure 4.1.
Therefore, pad voltage of 5V tolerant IO for 2.5V interface could be 1.60V instead of VDD, and pad voltage of
5V tolerant IO for 3.3V interface could be 2.30V instead of VDD.
Figure 4-1.
Y
PO
PI
VDD
PAD
B
A
TN
EN
A