EVALUATION KIT AVAILABLE Click here to ask about the production status of specific part numbers. DS1925 iButton High-Capacity Temperature Logger with 122KB Data-Log Memory General Description Benefits and Features The iButton temperature logger (DS1925) is a rugged, Provides High-Quality Temperature Exposure self-sufficient system that measures temperature and Assessment of an End Product records the result in a protected memory section. The Temperature Measurement Accuracy of 0.5C recording is done at a user-defined rate. A total of 122K with Storage for Up to 125,440 Timestamped 8-bit readings or 61K 16-bit readings taken at equidistant Values Flexibility to Monitor and Data-Log Long Duration intervals ranging from 5min to 273hrs can be stored. In addition, there are 512 bytes of nonvolatile memory for Exposures with Short-Duration Time Intervals Unique Factory-Lasered 64-Bit Serial Number En- storing application-specific information. A mission to col- lect data can be programmed to begin immediately, after sures Absolute Traceability Because No Two Parts Are Alike a user-defined delay, or after a temperature alarm. Access to the memory and control functions can be password Highly Configurable Options for Data Logging and protected. The DS1925 is configured and communicates Security with a host computing device through the serial 1-Wire Programmable Sample Rates from 5min to 273hrs protocol, which requires only a single data lead and a Programmable Recording Start Delay After Elapsed ground return. Every DS1925 is factory-lasered with a Time or Upon a Temperature Alarm Trip Point guaranteed unique 64-bit registration number that allows Two-Level Password Protection of All Memory and for absolute traceability. The durable stainless-steel pack- Configuration Registers age is highly resistant to environmental hazards such as Measure and Report Internal Battery Level and dirt, moisture, and shock. Accessories permit the DS1925 Output-Logged Data if a Battery is Depleted to be mounted on almost any object, including containers, Physically Robust, Operationally Efficient pallets, and bags. Durable Stainless-Steel Enclosure Withstands Harsh Environments and Conditions Applications Communicates to a Host System with the Single- Temperature Logging in Cold Chain Contact 1-Wire Interface Food Safety -40C to +85C Operating Temperature Range Bio Science Pharmaceutical and Medical Products High-Tempera- Ordering Information appears at end of data sheet. ture Logging (Process Monitoring, Industrial Monitoring) Typical Application Circuit Examples of Accessories V CC PART ACCESSORY DS9093RA Mounting Lock Ring 10k DS9093A Snap-in FOB DS9092 iButton Probe R PUP PIOX DS1402D-DR8+ Blue Dot Receptor Cable C 02 53 PIOY 000000FBC52B 1-Wire Thermochron iButton and 1-Wire are registered trademarks of Maxim Integrated Products, Inc. 19-8480 Rev 4 6/20DS1925 iButton High-Capacity Temperature Logger with 122KB Data-Log Memory Absolute Maximum Ratings IO Voltage to GND ..................................................-0.3V to +6V Junction Temperature ......................................................+150C IO Sink Current...................................................................20mA Storage Temperature Range .............................-40C to +85C* Operating Temperature Range ........................... -40C to +85C *Storage or operation above +50C significantly reduces battery life. 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 (V = 3.0V to 5.25V, unless otherwise noted.) PUP PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Temperature T (Note 1) -40 +85 C A IO PIN: GENERAL DATA 1-Wire Pullup Resistance R (Notes 2, 3) 2200 PUP Input Capacitance C (Note 4) 120 nF IO Input Leakage Current I IO pin at V 6 60 A L PUP High-to-Low Switching 0.5 x V (Notes 5, 6) V TL Threshold V PUP Input Low Voltage V (Notes 2, 7) 0.4 V IL Low-to-High Switching 0.75 x V (Notes 5, 8) V TH Threshold V PUP 0.2 x Switching Hysteresis V (Note 9) V HY V PUP Output Low Voltage V At 4mA (Note 10) 0.4 V OL Standard speed, R = 2200 5 PUP Recovery Time Overdrive speed, R = 2200 2 PUP t s REC (Note 2) Overdrive speed, directly prior to reset 5 pulse R = 2200 PUP Standard speed 65 Time Slot Duration (Note 2) t s SLOT Overdrive speed 8 Rising-Edge Hold-Off Time t (Note 11) 0.1 s REH IO PIN: 1-Wire RESET, PRESENSE-DETECT CYCLE Standard speed, V 480 640 PUP Reset Low Time (Note 2) t s RSTL Overdrive speed 48 80 Standard speed 65 75 Presence-Detect Sample t s MSP Time (Note 2) Overdrive speed 8 10 Maxim Integrated 2 www.maximintegrated.com