DS2404
EconoRAM Time Chip
www.dalsemi.com
FEATURES
§
4096 bits of nonvolatile dual-port memory
including real time clock/calendar in binary
format, programmable interval timer, and
programmable power-on cycle counter
§
1-Wire
TM
interface for MicroLAN
communication at 16.3k bits per second
§
3-wire host interface for high-speed data
communications at 2M bits per second
§
Unique, factory-lasered and tested 64-bit
registration number (8-bit family code + 48-
bit serial number + 8-bit CRC tester) assures
absolute traceability because no two parts are
alike
§
Memory partitioned into 16 pages of 256-bits
for packetizing data
§
256-bit scratchpad with strict read/write
protocols ensures integrity of data transfer
§
Programmable alarms can be set to generate
interrupts for interval timer, real time clock,
and/or cycle counter
§
16-pin DIP, SOIC and SSOP packages
§
Operating temperature range from -40°C to
+85°C
§
Operating voltage range from 2.8 to 5.5
Volts
PIN ASSIGNMENT
VCC
IRQ
RST
DQ
I/O
CLK
NC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
X1
X2
GND
NC
1HZ
VBATO
VBATB
16-PIN DIP (300 MIL)
16-PIN SOIC (300 MIL)
16-PIN SSOP (300 MIL)
See Mechanical Drawings Section
PIN DESCRIPTION
V
CC
IRQ
RST
DQ
I/O
CLK
NC
GND
V
BATB
V
BATO
1 Hz
X
1
,X
2
–
–
–
–
–
–
–
–
–
–
–
–
2.8 to 5.5 Volts
Interrupt Output
3-Wire Reset Input
3-Wire Input/Output
1-Wire Input/Output
3-Wire Clock Input
No Connection
Ground
Battery Backup Input
Battery Operate Input
1 Hz Output
Crystal Connections
ORDERING INFORMATION
DS2404
DS2404S
DS2404B
16-pin DIP
16-pin SOIC
16-pin SSOP
DESCRIPTION
The DS2404 EconoRAM Time Chip offers a simple solution for storing and retrieving vital data and time
information with minimal hardware. The DS2404 contains a unique lasered ROM, real-time
clock/calendar, interval timer, cycle counter, programmable interrupts and 4096-bits of SRAM. Two
separate ports are provided for communication, 1-Wire and 3-wire. Using the 1-Wire port, only one pin is
required for communication, and the lasered ROM can be read even when the DS2404 is without power.
The 3-wire port provides high speed communication using the traditional Dallas Semiconductor 3-wire
interface. With either interface, a strict protocol for accessing the DS2404 ensures data integrity. Utilizing
backup energy sources, the data is nonvolatile and allows for stand-alone operation.
The DS2404 features can be used to create a stopwatch, alarm clock, time and date stamp, logbook, hour
meter, calendar, system power cycle timer, expiration timer, and event scheduler.
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020998
DALLAS [ DALLAS SEMICONDUCTOR ]
