CAT24FC32A Datasheet, PDF (6/12 Pages) Catalyst Semiconductor – 32K-Bit Fast Mode I2C Serial CMOS EEPROM

CAT24FC32A
PIN DESCRIPTION
SCL: Serial Clock
The serial clock input clocks all data transferred into or
out of the device. The SCL line requires a pull-up resistor
if it is driven by an open drain output.
SDA: Serial Data/Address
The bidirectional serial data/address pin is used to
transfer all data into and out of the device. The SDA pin
is an open drain output and can be wire-ORed with other
open drain or open collector outputs. A pull-up resistor
must be connected from SDA line to Vcc. The value of
the pull-up resistor, Rp, can be calculated based on
minimum and maximum values from Figure 4 and Figure
5. (see Note).
WP: Write Protect
This input controls the device write protect feature. WP
pin connected to V_SS allows write operations to the entire
memory. When this pin is connected to Vcc, the entire
memory is write protected. When left floating, an internal
pull-down resistor on this input will keep the memory
unprotected. Read operations are not affected.
A0, A1, A2: Device Address Inputs
These inputs are used for extended addressing capability.
The A0, A1, A2 pins can be hardwired to VCC or VSS, or
left unconnected. When hardwired, up to eight
CAT24FC32As may be addressed on a single bus
system. When the pins are left unconnected, the default
values are zero. The levels on these inputs are compared
with corresponding bits, A2, A1, A0, from the slave
address byte.
Minimum RP as a Function of Supply Voltage
(IOL = 3mA @ VOLmax)
1
0.5
0
1.6
2 2.4 2.8 3.2 3.6
VCC (V)
Figure 4
Minimum RP Value versus Bus Capacitance
(Fast Mode I2C Bus / tr max = 300ns)
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
50 100 150 200 250 300 350 400
Cbus (pF)
Figure 5
Note: According to the Fast Mode I²C bus specification, for bus capacitance up to 200pF, the pull up device
can be a resistor. For bus loads between 200pF and 400pF, the pull-up device can be a current source
(Imax=3mA) or a switched resistor circuit.
Doc. No. 1048, Rev. F
6