CAT24C21 Datasheet, PDF (1/12 Pages) Catalyst Semiconductor – 1-kb Dual Mode Serial EEPROM for VESA™ Plug-and-Play

CAT24C21
1-kb Dual Mode Serial EEPROM for VESA™ "Plug-and-Play"
FEATURES
ALOGEN ^FR
LEA _{D F REETM}
s DDC1^TM/DDC2^TM interface compliant for
monitor identification
s 400 kHz I²C bus compatible*
s 2.5 to 5.5 volt operation
s 16-byte page write buffer
s Hardware write protect
s Low power CMOS technology
s 1,000,000 program/erase cycles
s 100 year data retention
s 8-pin DIP, SOIC, TSSOP, MSOP or TDFN
packages
s Industrial temperature range
DESCRIPTION
The CAT24C21 is a 1-kb Serial CMOS EEPROM
internally organized as 128 words of 8 bits each. The
device complies with the Video Electronics Standard
Association's (VESA™), Display Data Channel (DDC™)
standards for "Plug-and-Play" monitors. The "transmit-
only" mode (DDC1™) is controlled by the VCLK clock
input and the "bi-directional" mode (DDC2™) is controlled
by the SCL clock input, with both modes sharing a
common SDA input/output (I/O). The transmit-only mode
is a read-only mode, while the bi-directional mode is a
read and write mode following the I²C protocol. In write
mode the CAT24C21 features a 16-byte page write
buffer. The device is available in 8-in DIP, SOIC, TSSOP,
MSOP and TDFN packages.
PIN CONFIGURATION
DIP Package (P, L)
SOIC Package (J, W)
NC 1
NC 2
NC 3
VSS ⁴
8 _VCC
7 _VCLK
6 _SCL
5 _SDA
NC 1
NC 2
NC 3
VSS 4
8 VCC
7 VCLK
6 SCL
5 SDA
MSOP Package (R, Z)
TDFN Package (RD4, ZD4)
NC ¹
NC ²
NC ³
VSS
4
8
VCC
7 VCLK
6 SCL
5 SDA
TSSOP Package (U, Y)
NC 1
NC ²
NC ³
VSS ⁴
8 VCC
7 VCLK
6 SCL
5 _SDA
3 mm x 3 mm
Top View
NC
1
NC
2
NC
3
VSS
4
8
VCC
7 _VCLK
6 _SCL
5 _SDA
* Catalyst Semiconductor is licensed by Philips Corporation to carry the I²C Bus
Protocol.
FUNCTIONAL SYMBOL
VCC
SCL
VCLK
CAT24C21
SDA
VSS
PIN FUNCTIONS
Pin Name
Function
NC
No Connect
SDA
Serial Data/Address
SCL
Serial Clock (bi-directional mode)
VCLK
Serial Clock (transmit-only mode)
V_CC
Power Supply
V_SS
Ground
© 2004 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 1032, Rev. O