DS1371 2 I C, 32-Bit Binary Counter Watchdog Clock www.maxim-ic.com General Description Features The DS1371 is a 32-bit binary counter that is 32-Bit Binary Counter designed to continuously count time in seconds. 24-Bit Binary Counter Provides Periodic An additional counter that can generate a Alarm, Watchdog Timer, or RAM periodic alarm or serve as a watchdog timer is Strobe Input to Reset Watchdog Timer also provided. If enabled as a watchdog timer, Single Output Configurable as Interrupt or the watchdog strobe input pin provides a Square Wave 2 hardware reset of the counter. If disabled, this I C Serial Interface counter can be used as 3 Bytes of general- Low-Voltage Operation purpose RAM. A configurable output can be Operating Temperature Range: used as an interrupt or provide a square wave at -40C to +85C one of four selectable frequencies. The device is Available in 8-Pin SOP 2 programmed serially through a I C bidirectional bus. Ordering Information PIN- TOP PART TEMP RANGE Applications PACKAGE MARK Servers DS1371U -40C to +85C 8 SOP 1371 Point-of-Sale Equipment DS1371U+ -40C to +85C 8 SOP 1371 Portable Instruments Elapsed Time Measurements +Denotes a lead-free/RoHS-compliant package. A + appears on the top mark for lead-free packages. Typical Operating Circuit Pin Configuration TOP VIEW X1 1 8 V CC X2 2 7 SQW/INT DS1371 WDS 3 6 SCL GND 4 5 SDA SOP 1 of 15 REV: 070607 DS1371 ABSOLUTE MAXIMUM RATINGS Voltage Range on V Pin Relative to Ground..-0.3V to +6.0V CC Voltage Range on SDA, SCL, and WDS Relative to Ground..-0.3V to (V +0.5V) CC Operating Temperature Range (noncondensing)...-40C to +85C Storage Temperature Range.-55C to +125C Soldering Temperature...See IPC/JEDEC J-STD-020 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 can affect device reliability. RECOMMENDED DC OPERATING CONDITIONS (T = -40C to +85C) A PARAMETER SYMBOL MIN TYP MAX UNITS Supply Voltage (Note 1) V 1.7 3.3 5.5 V CC Input Logic 1 (Notes 2, 3) V 0.7 V V + 0.3 V IH CC CC Input Logic 0 (Notes 2, 3) V -0.3 0.3V V IL CC DC ELECTRICAL CHARACTERISTICS (V = 1.7V to 5.5V, T = -40C to +85C, unless otherwise noted.) (Note 4) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage (Note 1) V 1.7 5.5 V CC Oscillator Operating Voltage V 1.3 5.5 V OSC Range (Note 1) Input Leakage I (Note 2) 1 A LI I/O Leakage I (Note 3) 1 A LO V > 2V V = 0.4V CC OL SDA Logic 0 Output (Note 1) I 3 mA OLSDA V < 2V V = 0.2V CC OL CC V > 2V V = 0.4V 3.0 CC OL mA 1.7V < V < 2V CC SQW/INT Logic 0 Output 3.0 I V = 0.2V OLSQW OL CC (Note 1) 1.3V < V < 1.7V CC 250 A V = 0.2V OL CC Active Supply Current I (Note 5) 100 150 A CCA Timekeeping Current I (Notes 6, 7) 800 nA OSC0 (Oscillator Enabled, INTCN = 1) Timekeeping Current I (Notes 6, 7) 1300 nA OSC1 (Oscillator Enabled, INTCN = 0) Data Retention Current I (Note 6) 100 nA DDR (Oscillator Disabled) 2 of 15