DS28EC20 Maxim, DS28EC20 Datasheet - Page 6

• Manufacturer Part Number: DS28EC20
• Description: The DS28EC20 is a 20480-bit, 1-Wire® EEPROM organized as 80 memory pages of 256 bits each
• Manufacturer: Maxim

PIN DESCRIPTION
DESCRIPTION
The DS28EC20 combines 20Kb of data EEPROM with a fully featured 1-Wire interface in a single chip. The
memory is organized as 80 pages of 256 bits each. In addition, the device has one page for control functions such
as permanent write protection and EPROM-Emulation mode for individual 2048-bit (8-page) memory blocks. A
volatile 256-bit memory page called the scratchpad acts as a buffer when writing data to the EEPROM to ensure
data integrity. Data is first written to the scratchpad, from which it can be read back for verification before
transferring it to the EEPROM. The operation of the DS28EC20 is controlled over the single-conductor 1-Wire bus.
Device communication follows the standard 1-Wire protocol. The energy required to read and write the DS28EC20
is derived entirely from the 1-Wire communication line. Each DS28EC20 has its own unalterable and unique 64-bit
registration number. The registration number guarantees unique identification and is used to address the device in
a multidrop 1-Wire net environment. Multiple DS28EC20 devices can reside on a common 1-Wire bus and be
operated independently of each other. Applications of the DS28EC20 include device authentication, analog-sensor
calibration such as IEEE-P1451.4 Smart Sensors TEDS, ink and toner print cartridge identification, medical-sensor
calibration data storage, PC board identification, and data for self-configuration of central office switches, wireless
base stations, PBXs, or other modular-based rack systems. The DS28EC20 provides a high degree of backward
compatibility with the DS2433. Besides the different family codes, the only protocol change that is required on an
existing DS2433 implementation is a lengthening of the programming duration (t
Figure 1. Block Diagram
NAME
GND
N.C.
I/O
1-Wire Bus Interface. Open drain, requires external pullup resistor.
Ground Reference
Not Connected
DS28EC20
I/O
Special Function
32 Bytes each
Data Memory
80 Pages of
Control Unit
Generator
Registers
Function
Memory
CRC16
FUNCTION
Function Control
1-Wire
6 of 27
Parasite Power
Registration #
Scratchpad
32-Byte
64-Bit
DS28EC20: 20Kb 1-Wire EEPROM
PROG
) from 5ms to 10ms.