DS28EC20 Datasheet, PDF (1/24 Pages) Dallas Semiconductor – 20Kb 1-Wire EEPROM

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GENERAL DESCRIPTION
The DS28EC20 is a 20480-bit, 1-Wire^® EEPROM
organized as 80 memory pages of 256 bits each. An
additional page is set aside for control functions.
Data is written to a 32-byte scratchpad, verified, and
then copied to the EEPROM memory. As a special
feature, blocks of eight memory pages can be write
protected or put in EPROM-Emulation mode, where
bits can only be changed from a 1 to a 0 state. The
DS28EC20 communicates over the single-conductor
1-Wire bus. The communication follows the standard
1-Wire protocol. Each device has its own unalterable
and unique 64-bit ROM registration number that is
factory lasered into the chip. The registration number
is used to address the device in a multidrop 1-Wire
net environment.
APPLICATIONS
Device Authentication
IEEE 1451.4 Sensor TEDS
Ink/Toner Cartridges
Medical Sensors
PCB Identification
Wireless Base Stations
ORDERING INFORMATION
PART
TEMP RANGE
PIN-
PACKAGE
DS28EC20+ -40°C to +85°C 3 TO-92
DS28EC20+T -40°C to +85°C 3 TO-92, T&R
+ Denotes a lead-free package.
T = tape and reel
TYPICAL OPERATING CIRCUIT
VCC
RPUP (300Ω
to 2.2kΩ)
PX.Y
µC
I/O
DS28EC20
GND
DS28EC20
20Kb 1-Wire EEPROM
FEATURES
ƒ 20480 Bits of Nonvolatile (NV) EEPROM
Partitioned into Eighty 256-Bit Pages
ƒ Individual 8-Page Groups of Memory Pages
(Blocks) can be Permanently Write Protected or
Put in OTP EPROM-Emulation Mode ("Write to
0")
ƒ Read and Write Access Highly Backward-
Compatible to Legacy Devices (e.g., DS2433)
ƒ 256-Bit Scratchpad with Strict Read/Write
Protocols Ensures Integrity of Data Transfer
ƒ 200k Write/Erase Cycle Endurance at +25°C
ƒ Unique Factory-Programmed 64-Bit Registration
Number Ensures Error-Free Device Selection
and Absolute Part Identity
ƒ Switchpoint Hysteresis and Filtering to Optimize
Performance in the Presence of Noise
ƒ Communicates to Host at 15.4kbps or 125kbps
Using 1-Wire Protocol
ƒ Low-Cost TO-92 Package
ƒ Operating Range: 5V ±5%, -40°C to +85°C
ƒ IEC 1000-4-2 Level 4 ESD Protection (8kV
Contact, 15kV Air, Typical) for I/O Pin
PIN CONFIGURATION
DALLAS
28EC20
PIN 1 ---------- GND
PIN 2 ---------- I/O
PIN 3 ---------- N.C.
123
FOR TAPE-AND-
REEL THE LEADS
ARE FORMED TO
100 MILS (2.54mm)
SPACING VERSUS
50 MILS (1.27mm)
FOR BULK.
123
BOTTOM VIEW
Commands, bytes, and modes are capitalized for
clarity.
1-Wire is a registered trademark of Dallas Semiconductor Corp., a
wholly owned subsidiary of Maxim Integrated products, Inc.
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REV: 071007