DS1972 m Y Y o W c W . Z Z Z n 19-4888 Rev 4 1/12 1024-Bit EEPROM iButton General Description Features The DS1972 is a 1024-bit, 1-Wire EEPROM chip orga- 1024 Bits of EEPROM Memory Partitioned Into nized as four memory pages of 256 bits each in a Four Pages of 256 Bits rugged iButton package. Data is written to an 8-byte Individual Memory Pages Can Be Permanently scratchpad, verified, and then copied to the EEPROM Write Protected or Put in EPROM-Emulation Mode memory. As a special feature, the four memory pages (Write to 0) can individually be write protected or put in EPROM- emulation mode, where bits can only be changed from Switchpoint Hysteresis and Filtering to Optimize a 1 to a 0 state. The DS1972 communicates over the Performance in the Presence of Noise single-conductor 1-Wire bus. The communication fol- IEC 1000-4-2 Level 4 ESD Protection (8kV lows the standard 1-Wire protocol. Each device has its Contact, 15kV Air, Typical) own unalterable and unique 64-bit ROM registration Reads and Writes Over a Wide Voltage Range number that is factory lasered into the device. The reg- istration number is used to address the device in a mul- from 2.8V to 5.25V from -40C to +85C tidrop, 1-Wire net environment. Communicates to Host with a Single Digital Signal at 15.4kbps or 125kbps Using 1-Wire Applications Protocol Access Control/Parking Meter Common iButton Features Work-in-Progress Tracking Unique Factory-Lasered 64-Bit Registration Tool Management Number Ensures Error-Free Device Selection and Inventory Control Absolute Traceability Because No Two Parts are Maintenance/Inspection Data Storage Alike Built-In Multidrop Controller for 1-Wire Net Examples of Accessories Chip-Based Data Carrier Stores Digital PART ACCESSORY Identification and Information, Armored in a DS9096P Self-Stick Adhesive Pad Durable Stainless-Steel Case DS9101 Multipurpose Clip Data Can Be Accessed While Affixed to Object DS9093RA Mounting Lock Ring Button Shape is Self-Aligning with Cup-Shaped DS9093A Snap-In Fob Probes DS9092 iButton Probe Easily Affixed with Self-Stick Adhesive Backing, Latched by its Flange, or Locked with a Ring Pin Configurations Pressed Onto its Rim Presence Detector Acknowledges When Reader F3 SIZE F5 SIZE First Applies Voltage 3.10mm 5.89mm 0.51mm 0.51mm BRANDING Ordering Information PART TEMP RANGE PIN-PACKAGE 16.25mm DS1972-F5+ -40C to +85C F5 iButton 52 2D DS1972-F3+ -40C to +85C F3 iButton 0000006234FB +Denotes a lead(Pb)-free/RoHS-compliant package. 1-Wire 17.35mm IO IO GND GND 1-Wire and iButton are registered trademarks of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. D o S 1 t 9 t 7 2 u - F B 5 i1024-Bit EEPROM iButton ABSOLUTE MAXIMUM RATINGS IO Voltage Range to GND .......................................-0.5V to +6V Junction Temperature......................................................+150C IO Sink Current ...................................................................20mA Storage Temperature Range .............................-55C to +125C Operating Temperature Range ...........................-40C to +85C 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 specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (T = -40C to +85C, unless otherwise noted.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS IO PIN: GENERAL DATA 1-Wire Pullup Voltage V (Note 2) 2.8 5.25 V PUP 1-Wire Pullup Resistance R (Notes 2, 3) 0.3 2.2 k PUP Input Capacitance C (Notes 4, 5) 1000 pF IO Input Load Current I IO pin at V 0.05 6.7 A L PUP V - PUP High-to-Low Switching Threshold V (Notes 5, 6, 7) 0.5 V TL 1.8 Input Low Voltage V (Notes 2, 8) 0.5 V IL V - PUP Low-to-High Switching Threshold V (Notes 5, 6, 9) 1.0 V TH 1.0 Switching Hysteresis V (Notes 5, 6, 10) 0.21 1.70 V HY Output Low Voltage V At 4mA (Note 11) 0.4 V OL Standard speed, R = 2.2k 5 PUP Overdrive speed, R = 2.2k 2 Recovery Time PUP t s REC (Notes 2, 12) Overdrive speed, directly prior to reset 5 pulse R = 2.2k PUP Standard speed 0.5 5.0 Rising-Edge Hold-Off Time t s REH (Notes 5, 13) Overdrive speed Not applicable (0) Standard speed 65 Time Slot Duration t s SLOT (Notes 2, 14) Overdrive speed 8 IO PIN: 1-Wire RESET, PRESENCE-DETECT CYCLE Standard speed 480 640 Reset Low Time (Note 2) t s RSTL Overdrive speed 48 80 Standard speed 15 60 Presence-Detect High Time t s PDH Overdrive speed 2 6 Standard speed 60 240 Presence-Detect Low Time t s PDL Overdrive speed 8 24 Standard speed 60 75 Presence-Detect Sample Time t s MSP (Notes 2, 15) Overdrive speed 6 10 2 DS1972