V4082 Datasheet, PDF (1/7 Pages) EM Microelectronic - MARIN SA – Identification ROM

EM MICROELECTRONIC - MARIN SA
V4082
Identification ROM
Description
The V4082 is a 64-bit read only memory (ROM) which
contains a unique laser engraved serial number. The
data in the ROM is partitioned into three sections: An 8-
bit identifier code, a 48-bit serial number and an 8-bit
cyclical redundancy check (CRC). The serial number is
incremented in fabrication such that no two parts have the
same code. Communication for reading and writing is
done serially via a single data lead (and ground return)
using a single wire protocol. Power for reading is derived
from the data line itself with no need for an extra power
source. The circuit is available in SOT 223 or TO 92
package.
Typical Operating Configuration
Vcc
R_PUP
5k
on chip supply
DATA
TX
RX
Cext
SYSTEM
1M
VSS
100 ohm
MOSFET
V4082
Control
Logic
+ ROM
Features
ƒ Unique 48-bit silicon serial number gives 10¹⁴
combinations
ƒ Factory lasered and tested, no two parts alike
ƒ 8-bit cyclic redundancy check ensures error-free reading
ƒ Presence detect indicates to the system when first
contact is made
ƒ Zero standby power required
ƒ Custom serial numbers available
ƒ Pin compatible with DS 2400, DS 2401 in TO-92 and
SOT-223
Applications
ƒ Socket identification
ƒ PCB identification
ƒ Equipment registration
Pin Assignment
TO -92
View
Fla t Front
V4082
1 23
SO T-223
4
V4082
1
2
3
Fig. 1
Pin
Pin Name
TO92 SOT-223
1
2
VSS
2
1
DATA
3
3
NC
4*
VSS
* Internally connected to pin 2
Function
Ground return
Serial data pin
Ground return
Fig. 2
Copyright © 2004, EM Microelectronic-Marin SA
1
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