DS1990R MAXIM | Alldatasheet
Document overview
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Technical content
Features
♦ Upgrade of DS1990A Guarantees Presence Pulse on Contact ♦ Can Be Read in Less Than 5ms ♦ Operating Range: 2.8V to 6.0V, -40°C to +85°C Common iButton Features ♦ Unique Factory-Lasered 64-Bit Registration Number Ensures Error-Free Device Selection and Absolute Traceability Because No Two Parts are Alike ♦ Built-In Multidrop Controller for 1-Wire Net ♦ Digital Identification by Momentary Contact ♦ Data Can Be Accessed While Affixed to Object ♦ Economically Communicates to Bus Master with a Single Digital Signal at 16.3kbps ♦ Button Shape is 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 by its Flange, or Locked with a Ring Pressed Onto its Rim ♦ Presence Detector Acknowledges When Reader First Applies Voltage DS1990R Serial Number iButton Pin Configurations
Ordering Information
19-4894; Rev 4; 8/10 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. PART TEMP RANGE PIN-PACKAGE DS1990R-F5# -40 °C to +85°C F5 i Button DS1990R-F3# -40 °C to +85°C F3 i Button Examples of Accessories PART ACCESSORY DS9096P Self-Stick Adhesive Pad DS9101 Multipurpose Clip DS9093RA Mounting Lock Ring DS9093A Snap-In Fob DS9092 i Button Probe 16.25mm 5.89mm 0.51mm 3.10mm 0.51mm 17.35mm BRANDING F5 SIZE GNDGND IOIO F3 SIZE 89 01 000000FBC52B 1-Wire® iBut t o n® . com YYWW ZZZ DS1990R#F5 iButton and 1-Wire are registered trademarks of Maxim Integrated Products, Inc. #Denotes a RoHS-compliant device that may include lead(Pb) that is exempt under the RoHS requirements.
ELECTRICAL CHARACTERISTICS
(TA = -40°C to +85°C.) Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 1: All voltages are referenced to ground. Note 2: External pullup voltage. See Figure 4. Note 3: System requirement. Note 4: Full RPUP range is guaranteed by design and simulation and not production tested. Production testing performed at a fixed RPUP value. Maximum allowable pullup resistance is a function of the number of 1-Wire devices in the system and 1-Wire recovery times. The specified value here applies to systems with only one device and with the minimum 1-Wire recovery times. For more heavily loaded systems, an active pullup such as that found in the DS2480B may be required. Note 5: Capacitance on the IO pin could be 800pF when power is first applied. If a 5kΩ resistor is used to pull up the IO line to V PUP, 5µs after power has been applied the parasite capacitance will not affect normal communications. Note 6: Guaranteed by design, simulation only. Not production tested. Note 7: Input load is to ground. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS IO PIN: GENERAL DATA 1-Wire Pullup Voltage V PUP (Notes 1, 2) 2.8 6.0 V 1-Wire Pullup Resistance R PUP (Notes 3, 4) 0.6 5 k Input Capacitance C IO (Notes 5, 6) 100 800 pF Input Load Current I L (Note 7) 0.25 μA Input Low Voltage V IL (Notes 1, 3, 8) 0.3 V Input High Voltage V IH (Notes 1, 9) 2.2 V Output Low Voltage at 4mA V OL (Note 1) 0.4 V Operating Charge Q OP (Notes 6, 10) 30 nC Recovery Time t REC (Note 3) 1 μs Time Slot Duration t SLOT (Note 3) 61 μs IO PIN: 1-Wire RESET, PRESENCE-DETECT CYCLE Reset Low Time t RSTL (Notes 3, 11) 480 μs Reset High Time t RSTH (Notes 3, 12) 480 μs Presence-Detect High Time t PDH 15 60 μs Presence-Detect Low Time t PDL (Note 13) 60 240 μs Presence-Detect Sample Time t MSP (Note 3) 60 75 μs IO PIN: 1-Wire WRITE Write-Zero Low Time t W0L (Notes 3, 14) 60 120 μs Write-One Low Time t W1L (Notes 3, 14) 1 15 μs IO PIN: 1-Wire READ Read Low Time t RL (Notes 3, 15) 1 15 - μs Read Sample Time t MSR (Notes 3, 15) t RL + 15 μs
Note 8: The voltage on IO must be less than or equal to VILMAX whenever the master drives the line low. Note 9: VIH is a function of the internal supply voltage. Note 10: 30nC per 72 time slots at 5.0V pullup voltage with a 5kΩ pullup resistor and tSLOT ≤ 120µs. mask or conceal interrupt pulses if this device is used in parallel with a DS1994. Note 12: An additional reset or communication sequence cannot begin until the reset high time has expired. Note 13: Presence pulse after POR is guaranteed by design, not production tested. maximum duration for the master to pull the line low is tW1LMAX + tF - ε and tW0LMAX + tF - ε, respectively. threshold of the bus master. The actual maximum duration for the master to pull the line low is tRLMAX + tF. SIZE See the Package Information section. Figure 1. Block Diagram
the 1-Wire bus has a maximum data rate of 16.3kbps. mately 2.2kΩ. The idle state for the 1-Wire bus is high.
- Initialization
- ROM Function Command Initialization All transactions on the 1-Wire bus begin with an initial- ization sequence. The initialization sequence consists of a reset pulse transmitted by the bus master followed by presence pulse(s) transmitted by the slave(s). The presence pulse lets the bus master know that the DS1990R is on the bus and is ready to operate. For more details, see the 1-Wire Signaling section. DS1990R Serial Number iButton Rx RPUP VPUP SIMPLE BUS MASTER DS2480B BUS MASTER OPEN-DRAIN PORT PIN 100Ω MOSFET Tx Rx Tx DATA DS1990R 1-Wire PORT Rx = RECEIVE Tx = TRANSMIT VDD POL RXDSERIAL IN SERIAL OUT TXD VPP GND N.C. 1-W TO 1-Wire DATA +5V HOST CPU SERIAL PORT DS2480B
Figure 4. Hardware Configuration
Figure 7. Read/Write Timing Diagram
A read-data time slot begins like a write-one time slot. The voltage on the data line must remain below V ILMAX until the read low time t RL is expired. During the t RL window, when responding with a 0, the DS1990R starts pulling the data line low; its internal timing generator determines when this pulldown ends and the voltage starts rising again. When responding with a 1, the DS1990R does not hold the data line low at all, and the voltage starts rising as soon as t RL is over. The sum of tRL + δ (rise time) on one side and the inter- nal timing generator of the DS1990R on the other side define the master sampling window (t MSRMIN to tMSRMAX) in which the master must perform a read from the data line. For most reliable communication, t RL should be as short as permissible and the master should read close to but no later than t MSRMAX. After reading from the data line, the master must wait until t SLOT is expired. This guarantees sufficient recovery time t REC for the DS1990R to get ready for the next time slot. DS1990R Serial Number iButton
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages . Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawingpertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. F3 iButton IB#3NB 21-0252 — F5 iButton IB#5NB 21-0266 —
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
0 5/05 Initial release — 1 8/06 Reworded the UL#913 bullet to “Designed to meet...” 1 2 8/09 Updated the Ordering Information table to include RoHS-compliant packages; removed the UL#913 bullet from the Common iButton Features section 1 3 8/10 Created newer template-style data s heet; in the Electrical Characteristics table, deleted the Output High Voltage parameter, moved the 1-Wire Pullup voltage parameter from table header to table body, changed V ILMAX from 0.8V to 0.3V, added Note 14 to the t W0L specification, changed t W1LMAX from 15μs – to 15μs, and added more details to Notes 14 and 15; added the epsilon timing to the Write-Zero Time Slot in Figure 7 2, 3, 8