DS1990R Serial Number iButton GENERAL DESCRIPTION DS199

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

DS1990R Serial Number iButton GENERAL DESCRIPTION DS199

Datasheet Thumbnail

Top Searches for this datasheet

19-4894; 8/09
DS1990R
Serial Number iButton
GENERAL DESCRIPTION
DS1990R Serial Number iButton rugged data carrier that serves electronic registration number automatic identification. Data transferred serially through 1-Wire protocol, which requires only single data lead ground return. Every DS1990R factory lasered with guaranteed unique 64-bit registration number that allows absolute traceability. durable stainless-steel iButton package highly resistant environmental hazards such dirt, moisture, shock. compact coin-shaped profile self-aligning with mating receptacles, allowing DS1990R used easily human operators. Accessories permit DS1990R iButton mounted almost object, including containers, pallets, bags. DS1990R fully compatible variant DS1990A. applications where presence pulse contact critical DS1990R should preferred over DS1990A.
SPECIAL FEATURES
Upgrade DS1990A Guarantees Presence Pulse Contact Read Less Than Operating Range: 2.8V 6.0V, -40°C +85°C
COMMON iButton FEATURES
Unique Factory-Lasered 64-Bit Registration Number Assures Error-Free Device Selection Absolute Traceability Because Parts Alike Built-In Multidrop Controller 1-Wire Digital Identification Momentary Contact Data Accessed While Affixed Object Economically Communicates Master with Single Digital Signal 16.3kbps Button Shape Self-Aligning with Cup-Shaped Probes Durable Stainless-Steel Case Engraved with Registration Number Withstands Harsh Environments Easily Affixed with Self-Stick Adhesive Backing, Latched Flange, Locked with Ring Pressed Onto Presence Detector Acknowledges when Reader First Applies Voltage
APPLICATIONS
Access Control Work-In-Progress Tracking Tool Management Inventory Control
MicroCAN
size
3.10 0.51
ORDERING INFORMATION
Branding
0.51
size
5.89
PART DS1990R-F5# DS1990R-F3#
16.25
TEMP RANGE -40°C +85°C -40°C +85°C
PIN-PACKAGE iButton iButton
#Denotes RoHS-compliant device that include lead(Pb) that exempt under RoHS requirements.
000000FBC52B
1-Wire
EXAMPLES ACCESSORIES
17.35
PART DS9096P DS9101 DS9093RA DS9093A DS9092
DESCRIPTION Self-Stick Adhesive Multipurpose Clip Mounting Lock Ring Snap-In iButton Probe
dimensions shown millimeters.
iButton 1-Wire registered trademarks Maxim Integrated Products, Inc.
Note: Some revisions this device incorporate deviations from published specifications known errata. Multiple revisions device simultaneously available through various sales channels. information about device errata, click here: www.maxim-ic.com/errata.
DS1990R: Serial Number iButton
PHYSICAL SPECIFICATION
Size Weight DS1990R Mechanical Drawing grams
ABSOLUTE MAXIMUM RATINGS
Voltage Sink Current Junction Temperature Storage Temperature Range -0.5V, +6.0V 20mA +125°C -55°C +125°C
Stresses beyond those listed under "Absolute Maximum Ratings" cause permanent damage device. These stress ratings only, functional operation device these other conditions beyond those indicated operational sections specifications implied. Exposure absolute maximum rating conditions extended periods affect device.
ELECTRICAL CHARACTERISTICS
PARAMETER SYMBOL CONDITIONS General Data 1-Wire Pullup Resistance RPUP (Notes Input Capacitance (Note Input Load Current (Note Input Voltage (Notes Input High Voltage (Notes Output-Low Voltage (Note Output-High Voltage (Notes Operating Charge (Note Recovery Time tREC (Note Timeslot Duration tSLOT (Note Pin, 1-Wire Reset, Presence Detect Cycle Reset Time tRSTL (Notes Reset High Time tRSTH (Notes Presence Detect High Time tPDH Presence Detect Time tPDL (Note Presence Detect Sample tMSP (Note Time Pin, 1-Wire Write Write-0 Time tW0L (Note Write-1 Time tW1L (Notes Pin, 1-Wire Read Read Time (Notes Read Sample Time tMSR (Notes (VPUP 2.8V 6.0V, -40°C +85°C.) UNITS 0.25 VPUP
DS1990R: Serial Number iButton
Note Note
Note Note Note Note Note Note Note Note Note Note Note Note Note
System requirement. Full Rpup range guaranteed design simulation, production tested. Production testing performed fixed Rpup value. Maximum allowable pullup resistance function number 1-Wire devices system 1-Wire recovery times. specified value here applies systems with only device with minimum 1-Wire recovery times. more heavily loaded systems, active pullup such that found DS2480 required. Capacitance could when power first applied. resistor used pull line VPUP, after power been applied parasite capacitance will affect normal communications. Guaranteed design, simulation only. production tested. Input load ground. voltage needs less equal VILMAX whenever master drives line low. Under certain voltage conditions, VILMAX have reduced much 0.5V always guarantee Presence Pulse. voltages referenced ground. function internal supply voltage. VPUP external pullup voltage. 30nC time slots 5.0V pullup voltage with pullup resistor tSLOT 120µs. reset time (tRSTL) should restricted maximum 960µs, allow interrupt signaling; longer duration could mask conceal interrupt pulses this device used parallel with DS1994. additional reset communication sequence cannot begin until reset high time expired. Presence pulse after guaranteed design, production tested. represents time required pullup circuitry pull voltage from VIH. represents time required pullup circuitry pull voltage from input-high threshold master.
DESCRIPTION
diagram Figure shows major function blocks device. DS1990R takes energy needs operate from line, indicated Parasite Power block. Function Control units includes 1Wire interface logic implement function commands, which access bits lasered ROM.
Figure DS1990R BLOCK DIAGRAM
Parasite Power
Function Control
64-bit Lasered
64-BIT LASERED
Each DS1990R contains unique code that bits long. first bits 1-Wire family code. next bits unique serial number. last bits first bits. Figure details. 1Wire generated using polynomial generator consisting Shift gates shown Figure polynomial Additional information about Dallas 1-Wire Cyclic Redundancy Check available Application Note Shift register bits initialized Then starting with least significant family code, time shifted After family code been entered, then serial number entered. After 48th serial number been entered, Shift register contains value. Shifting bits returns Shift register
DS1990R: Serial Number iButton
Figure 64-BIT LASERED
8-BIT CODE 48-BIT SERIAL NUMBER 8-BIT FAMILY CODE (01h)
Figure 1-WIRE GENERATOR
POLYNOMIAL
STAGE
STAGE
STAGE
STAGE
STAGE
STAGE
STAGE
STAGE
INPUT DATA
1-Wire SYSTEM
1-Wire system, which single master more slaves. instances DS1990R slave device. master typically microcontroller small configurations 1-Wire communication signals generated under software control using single port pin. Alternatively, DS2480B 1-Wire line driver chip serial port adapters based this chip (DS9097U series) used. This simplifies hardware design frees microprocessor from responding real-time. discussion this system broken down into three topics: hardware configuration, transaction sequence, 1-Wire signaling (signal types timing). 1-Wire protocol defines transactions terms state during specific time slots that initiated falling edge sync pulses from master. more detailed protocol description, refer Chapter Book DS19xx iButton Standards.
HARDWARE CONFIGURATION
1-Wire only single line definition; important that each device able drive appropriate time. facilitate this, each device attached 1-Wire must have open drain tri-state outputs. 1-Wire port DS1990R open-drain with internal circuit equivalent that shown Figure multidrop consists 1-Wire with multiple slaves attached. standard speed 1-Wire maximum data rate 16.3kbps. value pullup resistor primarily depends network size load conditions. most applications optimal value pullup resistor approximately 2.2k. idle state 1-Wire high. reason transaction needs suspended, MUST left idle state transaction resume. this does occur left more than 120µs, more devices reset.
TRANSACTION SEQUENCE
protocol accessing DS1990R through 1-Wire port follows: Initialization Function Command
DS1990R: Serial Number iButton
Figure HARDWARE CONFIGURATION
SIMPLE MASTER VPUP RPUP DATA MOSFET DS1990R 1-Wire PORT
Open Drain Port
Receive Transmit
DS2480B MASTER HOST Serial Port serial serial 1-Wire data
DS2480B
INITIALIZATION
transactions 1-Wire begin with initialization sequence. initialization sequence consists reset pulse transmitted master followed presence pulse(s) transmitted slave(s). presence pulse lets master know that DS1990R ready operate. more details, 1-Wire Signaling section.
1-Wire FUNCTION COMMANDS
Once master detected presence, issue function commands that DS1990R supports. function commands bits long. list these commands follows (see flowchart Figure
READ [33h] [0Fh]
This command allows master read DS1990R's 8-bit family code, unique 48-bit serial number, 8bit CRC. This command only used there single slave device bus. more than slave present bus, data collision will occur when slaves transmit same time (open drain will produce wired-AND result). resultant family code 48-bit serial number will result mismatch CRC.
SEARCH [F0h]
When system initially brought master might know number devices 1-Wire their registration numbers. taking advantage wired-AND property bus, master process elimination identify registration numbers slave devices. each registration number, starting with least significant bit, master issues triplet time slots. first slot, each slave device participating search outputs true value registration number bit. second slot, each slave device participating search outputs complemented value registration number bit. third slot, master writes true value selected. slave devices that match written master stop participating search. both read bits zero, master knows that slave devices exist with both states bit. choosing which state write, master branches code tree. After complete pass, master knows registration number single device. Additional passes identify registration numbers remaining devices. Refer Note 187: 1-Wire Search Algorithm detailed discussion, including example.
DS1990R: Serial Number iButton
Figure FUNCTIONS FLOW CHART
Master Reset Pulse
Master Function Command
DS1990R Presence Pulse
Read Command
Search Command
DS1990R Family Code Byte)
DS1990R DS1990R Master Match DS1990R DS1990R Master Match
DS1990R Serial Number Bytes)
DS1990R Byte
DS1990R DS1990R
Master Match
MATCH [55h] SKIP [CCh]
minimum 1-Wire function commands includes Match Skip command. Since DS1990R contains only 64-bit without additional data fields, Match Skip applicable. DS1990R will remain silent (inactive) upon receiving function command that doesn't support. This allows DS1990R coexist multidrop with other 1-Wire devices that respond Match Skip (example DS1990R DS1994).
DS1990R: Serial Number iButton
1-Wire SIGNALING
DS1990R requires strict protocols ensure data integrity. protocol consists four types signaling line: Reset Sequence with Reset Pulse Presence Pulse, Write-Zero, Write-One, Read-Data. Except presence pulse master initiates these signals. from idle active, voltage 1-Wire line needs fall from VPUP below VILMAX. from active idle, voltage needs rise from VILMAX above VIHMIN. time takes voltage make this rise, referenced Figure depends value pullup resistor (RPUP) capacitance 1-Wire network attached. initialization sequence required begin communication with DS1990R shown Figure Reset Pulse followed Presence Pulse indicates DS1990R ready receive function command. master uses slew-rate control falling edge, must pull down line tRSTL compensate edge.
Figure INITIALIZATION PROCEDURE "RESET PRESENCE PULSES"
MASTER "RESET PULSE" MASTER "PRESENCE PULSE" VPUP VIHMIN VILMAX tMSP
tRSTL
tPDH MASTER
tPDL tRSTH
tREC DS1990R
RESISTOR
After master released line goes into receive mode (RX). 1-Wire pulled VPUP pullup resistor case DS2480B driver, active circuitry. When VIHMIN crossed, DS1990R waits tPDH then transmits Presence Pulse pulling line tPDL. detect presence pulse, master must test logical state 1-Wire line tMSP.
READ/WRITE TIME SLOTS
Data communication with DS1990R takes place time slots, which carry single each. Write-time slots transport data from master slave. Read-time slots transfer data from slave master. definitions write read-time slots illustrated Figure communication begins with master pulling data line low. voltage 1-Wire line falls below VILMAX, DS1990R starts internal timing generator that determines when data line will sampled during write-time slot long data will valid during read-time slot.
MASTER-TO-SLAVE
write-one time slot, voltage data line must have risen above VIHMIN after write-one time tW1LMAX expired. write-zero time slot, voltage data line must stay below VILMAX until write-zero time tW0LMIN expired. most reliable communication voltage data line should exceed VILMAX during entire tW0L window. After voltage risen above VIHMIN, DS1990R needs recovery time tREC before ready next time slot.
DS1990R: Serial Number iButton
SLAVE-TO-MASTER
read-data time slot begins like write-one time slot. voltage data line must remain below VILMAX until read time expired. During window, when responding with DS1990R will start pulling data line low; internal timing generator determines when this pulldown ends voltage starts rising again. When responding with DS1990R will hold data line all, voltage starts rising soon over. (rise rime) side internal timing generator DS1990R other side define master sampling window (tMSRMIN tMSRMAX) which master must perform read from data line. most reliable communication, should short permissible master should read close later than tMSRMAX. After reading from data line, master must wait until tSLOT expired. This guarantees sufficient recovery time tREC DS1990R ready next time slot.
Figure READ/WRITE TIMING DIAGRAM
Write-One Time Slot
VPUP VIHMASTER VIHMIN VILMAX tW1L
tSLOT RESISTOR MASTER
Write-Zero Time Slot
VPUP VIHMASTER VIHMIN VILMAX RESISTOR MASTER tSLOT tW0L
tREC
Read-Data Time Slot
VPUP VIHMASTER VIHMIN VILMAX tMSR Master Sampling Window tSLOT RESISTOR MASTER DS1990R tREC
DS1990R: Serial Number iButton
REVISION HISTORY
REVISION DATE 8/09 DESCRIPTION Updated Ordering Information table include RoHS-compliant packages. Removed UL#913 bullet from Common iButton Features section. PAGES CHANGED
Maxim cannot assume responsibility circuitry other than circuitry entirely embodied Maxim product. circuit patent licenses implied. Maxim reserves right change circuitry specifications without notice time.
Maxim Integrated Products, Gabriel Drive, Sunnyvale, 94086 408-737-7600
2009 Maxim Integrated Products Maxim registered trademark Maxim Integrated Products, Inc.

DS1990R Serial Number iButton GENERAL DESCRIPTION DS199

Top Searches for this datasheet

Other recent searches