Pin Description

PIN

TSOC

TO-92

TDFN-EP

SFN

UCSPR

NAME

FUNCTION

3, 4, 5, 6

3

1, 4, 5, 6

—

A2, A3, C2,

C3

N.C.

Not Connected

2

2

2

1

C1

IO

1-Wire Bus Interface. Open-drain signal

that requires an external pullup resistor.

1

1

3

2

A1

GND

Ground Reference

—

—

—

—

—

EP

Exposed Pad (TDFN only). Solder

evenly to the board’s ground plane for

proper operation. Refer to Application

Note 3273: Exposed Pads: A Brief

Introduction for additional information.

1024-Bit, 1-Wire EEPROM

_______________________________________________________________________________________

5

Detailed Description

The DS2431 combines 1024 bits of EEPROM, an

8-byte register/control page with up to 7 user read/write

bytes, and a fully featured 1-Wire interface in a single

chip. Each DS2431 has its own 64-bit ROM registration

number that is factory lasered into the chip to provide a

guaranteed unique identity for absolute traceability.

Data

is

transferred

serially

through

the

1-Wire protocol, which requires only a single data lead

and a ground return. The DS2431 has an additional

memory area called the scratchpad that acts as a

buffer when writing to the main memory or the register

page. Data is first written to the scratchpad from which

it can be read back. After the data has been verified, a

Copy Scratchpad command transfers the data to its

final memory location. The DS2431 applications include

accessory/PCB identification, medical sensor calibra-

tion data storage, analog sensor calibration including

IEEE P1451.4 smart sensors, ink and toner print car-

tridge identification, and after-market management of

consumables.

Overview

The block diagram in Figure 1 shows the relationships

between the major control and memory sections of the

DS2431. The DS2431 has four main data components:

64-bit lasered ROM, 64-bit scratchpad, four 32-byte

pages of EEPROM, and a 64-bit register page.

MEMORY

FUNCTION

CONTROL UNIT

DATA MEMORY

4 PAGES OF

256 BITS EACH

CRC-16

GENERATOR

64-BIT

SCRATCHPAD

1-Wire

FUNCTION CONTROL

64-BIT

LASERED ROM

PARASITE POWER

IO

REGISTER PAGE

64 BITS

DS2431

Figure 1. Block Diagram