Rainbow Electronics DS2422 - Manual

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FEATURES
§ 4096 bits of SRAM (DS2423), 1024 bits with
the DS2422
§ Four 32-bit, read-only counters (DS2423),
three counters with the DS2422
§ Active-low external trigger inputs for two of
the counters with on-chip debouncing
compatible with reed and Wiegand switches
§ 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 16 256-bit pages in
DS2423 (4 pages in DS2422) for packetizing
data
§ 256-bit scratchpad with strict read/write
protocols ensures integrity of data transfer
§ On-chip 16-bit CRC generator for
safeguarding data transfers
§ Built-in multidrop controller ensures
compatibility with other MicroLAN products
§ Directly connects to a single port pin of a
microprocessor and communicates at up to
16.3kbits per second
§ Overdrive mode boosts communication speed
to 142kbits per second
§ 8-bit family code specifies device
communication requirements to reader
§ Presence detector acknowledges when reader
first applies voltage
§ Compact, low cost 6-pin TSOC surface mount
package
§ Reads, writes and counts over a wide voltage
range of 2.8V to 5.5V from -40°C to +85°C
PIN ASSIGNMENT
PIN DESCRIPTION
Pin 1 Ground
Pin 2 Data
Pin 3 Vbat
Pin 4 NC
Pin 5 Input channel B
Pin 6 Input channel A
ORDERING INFORMATION
DS2423P 6-pin TSOC package
DS2423P/T&R Tape & Reel Version of
DS2423P
DS2423X Chip Scale Pkg., Tape &
Reel
DS2422P Contact Factory
DESCRIPTION
The DS2422/DS2423 1-Wire ® RAM with Counters (hereafter referred to as DS242X) is a fully static,
read/write memory for battery operation in a low-cost, six-lead TSOC, surface-mount package. The
memory is organized as 16 pages (DS2423) or four pages (DS2422) of 256 bits each. In addition, the
device has four (DS2423) or three (DS2422) counters, two of them with external trigger inputs called A
and B. Each of the counters is associated with a memory page. A counter without external trigger input
increments each time data is written to the page it is associated with (write cycle counter). The counters
DS2422/DS2423
1kbit/4kbit 1-Wire
RAM with Counter
www.maxim-ic.com
1
2
3
6
5
4
TOP VIEW
3.7mm x 4.0mm x 1.5mm
SIDE VIEW
TSOC PACKAGE
1-Wire is a registered trademark of Dallas Semiconductor.