24lc32aft Microchip Technology Inc., 24lc32aft Datasheet - Page 5

• Manufacturer Part Number: 24lc32aft
• Description: 32k I 2 C? Serial Eeprom With Quarter-array Write-protect
• Manufacturer: Microchip Technology Inc.

2.0
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
2.1
The A0, A1 and A2 inputs are used by the 24XX32AF
for multiple device operation. The levels on these
inputs are compared with the corresponding bits in the
slave address. The chip is selected if the comparison is
true.
Up to eight devices may be connected to the same bus
by using different Chip Select bit combinations. These
inputs must be connected to either V
In most applications, the chip address inputs A0, A1
and A2 are hard-wired to logic ‘0’ or logic ‘1’. For
applications in which these pins are controlled by a
microcontroller or other programmable device, the chip
address pins must be driven to logic ‘0’ or logic ‘1’
before normal device operation can proceed. Address
pins are not available in the SOT-23 package.
2.2
SDA is a bidirectional pin used to transfer addresses
and data into and out of the device. It is an open-drain
terminal, therefore, the SDA bus requires a pull-up
resistor to V
400 kHz)
For normal data transfer, SDA is allowed to change
only during SCL low. Changes during SCL high are
reserved for indicating Start and Stop conditions.
© 2009 Microchip Technology Inc.
Name
SDA
SCL
V
V
WP
A0
A1
A2
SS
CC
PIN DESCRIPTIONS
A0, A1, A2 Chip Address Inputs
Serial Data (SDA)
CC
PDIP
(typical 10 kΩ for 100 kHz, 2 kΩ for
1
2
3
4
5
6
7
8
PIN FUNCTION TABLE
SOIC
1
2
3
4
6
7
8
5
CC
TSSOP
or V
1
2
3
4
5
6
7
8
SS
.
TDFN
1
2
3
4
5
6
7
8
MSOP
24AA32AF/24LC32AF
1
2
3
4
5
6
7
8
2.3
The SCL input is used to synchronize the data transfer
to and from the device.
2.4
This pin must be connected to either V
to V
write operations are inhibited for the upper 1/4 of the
array (C00h-FFFh), but read operations are not
affected.
SS
, write operations are enabled. If tied to V
SOT-23
Serial Clock (SCL)
Write-Protect (WP)
—
—
—
2
3
1
5
4
Chip Address Input
Chip Address Input
Chip Address Input
Ground
Serial Address/Data I/O
Serial Clock
Write-Protect Input
+1.7V to 5.5V Power Supply
Description
DS22184A-page 5
SS
or V
CC
. If tied
CC
,