Click here for production status of specific part numbers. DS28EA00 1-Wire Digital Thermometer with Sequence Detect and PIO General Description Features The DS28EA00 is a digital thermometer with 9-bit (0.5C) Digital Thermometer Measures Temperatures to 12-bit (1/16C) resolution and alarm function with non- from -40C to +85C volatile (NV), user-programmable upper and lower trigger Thermometer Resolution is User Selectable from points. Each DS28EA00 has its own unique 64-bit registra- 9 to 12 Bits tion number that is factory programmed into the chip. Data Unique 1-Wire Interface Requires Only One Port is transferred serially through the 1-Wire protocol, which Pin for Communication requires only one data line and a ground reference for com- munication. The improved 1-Wire front-end with hysteresis Each Device Has a Unique 64-Bit, Factory- and glitch filter enables the DS28EA00 to perform reliably Lasered Registration Number in large 1-Wire networks. Unlike other 1-Wire thermom- Multidrop Capability Simplifies Distributed eters, the DS28EA00 has two additional pins to implement Temperature-Sensing Applications a sequence-detect function. This feature allows the user to discover the registration numbers according to the physical Improved 1-Wire Interface with Hysteresis and device location in a chain, e.g., to measure the temperature Glitch Filter in a storage tower at different height. If the sequence-detect User-Definable NV Alarm Threshold Settings/User function is not needed, these pins can be used as general- Bytes purpose input or output. The DS28EA00 can derive the Alarm Search Command to Quickly Identify power for its operation directly from the data line (parasite power), eliminating the need for an external power supply. Devices Whose Temperature is Outside of Programmed Limits Applications Standard and Overdrive 1-Wire Speed Data Communication Equipment Two General-Purpose Programmable IO (PIO) Pins Process Temperature Monitoring Chain Function Sharing the PIO Pins to Detect HVAC Systems Physical Sequence of Devices in Network Operating Range: +3.0V to +5.5V, -40C to +85C Ordering Information Can Be Powered from Data Line PART TEMP RANGE PIN-PACKAGE 8-Pin SOP Package DS28EA00U+ -40C to +85C 8 SOP DS28EA00U+T&R -40C to +85C 8 SOP Pin Configuration appears at end of data sheet. +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. Typical Operating Circuit V DD 1-Wire 1 2 3 MASTER V V V DD DD DD PX. Y IO IO IO DS28EA00 DS28EA00 DS28EA00 MICROCONTROLLER PIOB PIOA PIOB PIOA PIOB PIOA GND GND GND NOTE: SCHEMATIC SHOWS PIO PINS WIRED FOR SEQUENCE-DETECT FUNCTION. 1-Wire is a registered trademark of Maxim Integrated Products, Inc. 19-7831 Rev 2 6/19DS28EA00 1-Wire Digital Thermometer with Sequence Detect and PIO Absolute Maximum Ratings IO Voltage Range to GND .......................................-0.5V to +6V Operating Temperature Range ........................... -40C to +85C IO Sink Current...................................................................20mA Junction Temperature ......................................................+150C Maximum PIOA or PIOB Pin Current .................................20mA Storage Temperature Range ............................ -55C to +125C Maximum Current Through GND Pin .................................40mA Soldering Temperature ..........................Refer to the IPC/JEDEC J-STD-020 Specification. 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.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Supply Voltage V (Note 2) 3.0 5.5 V DD Supply Current (Note 3) I V = +5.5V 1.5 mA DD DD Standby Current I V = +5.5V 1.5 A DDS DD IO PIN: GENERAL DATA Local power 3.0 V DD 1-Wire Pullup Voltage (Note 2) V V PUP Parasite power 3.0 5.5 1-Wire Pullup Resistance R (Notes 2, 4) 0.3 2.2 k PUP Input Capacitance C (Notes 3, 5) 1000 pF IO Input Load Current I IO pin at V 0.1 1.5 A L PUP V - PUP High-to-Low Switching Threshold V (Notes 3, 6, 7) 0.46 V TL 1.9V Parasite powered 0.5 Input Low Voltage (Notes 2, 8) V V IL V powered (Note 3) 0.7 DD Low-to-High Switching Threshold V - PUP V Parasite power 1.0 V TH (Notes 3, 6, 9) 1.1V Switching Hysteresis V Parasite power 0.21 1.7 V HY (Notes 3, 6, 10) Output Low Voltage (Note 11) V At 4mA 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 Rising-Edge Hold-Off Time Standard speed 0.5 5.0 t s REH (Notes 3, 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 Maxim Integrated 2 www.maximintegrated.com