2 DS1341/DS1342 Low-Current I C RTCs for High-ESR Crystals General Description Features The DS1341/DS1342 low-current real-time clocks (RTCs) Low Timekeeping Current of 250nA (typ) are timekeeping devices that provide an extremely low Compatible with Crystal ESR Up to 100k standby current, which permits longer life from a power Use Crystals with C = 6pF (DS1341) or L supply. The DS1341/DS1342 support high-ESR crystals, C = 12.5pF (DS1342) L which broaden the pool of usable crystals for the devices. The DS1341 uses a 6pF crystal, while the DS1342 uses +1.8V to +5.5V Operating Voltage Range a 12.5pF crystal. These devices are accessed through Maintain Time Down to +1.15V (typ) 2 an I C serial interface. Other features include two time- 2 Fast (400kHz) I C Interface of-day alarms, two interrupt outputs, a programmable square-wave output, and a serial bus timeout mechanism. Bus Timeout for Lockup-Free Operation The clock/calendar provides seconds, minutes, hours, RTC Counts Seconds, Minutes, Hours, Day, Date, day, date, month, and year information. The date at the Month, and Year with Leap Year Compensation Valid end of the month is automatically adjusted for months with Through 2099 fewer than 31 days, including corrections for leap year. External Clock Source for Synchronization Clock The clock operates in either 24hr or 12hr format with an Reference (e.g., 32kHz, 50Hz/60Hz Power Line, AM/PM indicator. GPS 1PPS) The DS1341/DS1342 also include an input for synchroni- Two Time-of-Day Alarms with Two Interrupt Outputs zation. When a reference clock (e.g., 60Hz power line or Programmable Square-Wave Output GPS 1PPS) is present at the CLKIN pin and the enable external clock input bit (ECLK) is set to 1, the DS1341/ Industrial Temperature Range DS1342 RTCs are frequency-locked to the external clock Small 8-Pin SOP or TDFN Packages and the clock accuracy is determined by the external source. In case of external clock failure, the clock is Applications switched to the crystal oscillator. Medical Portable Instruments The devices are available in lead(Pb)-free/RoHS- Point of Sale (POS) Portable Audio compliant, 8-pin SOP or TDFN packages. The devices Telematics support a -40C to +85C extended temperature range. Ordering Information Typical Operating Circuit PIN- OSC C L PART TEMP RANGE V V CC CC PACKAGE (pF) DS1341U+ -40C to +85C 8 SOP 6 DS1341U+T&R -40C to +85C 8 SOP 6 R R R PU PU PU DS1341T+ -40C to +85C 8 TDFN-EP* 6 V CC SCL X1 DS1341T+T&R -40C to +85C 8 TDFN-EP* 6 SDA DS1342U+ -40C to +85C 8 SOP 12.5 CLKIN/INTA DS1342U+T&R -40C to +85C 8 SOP 12.5 CPU SQW/INTB X2 DS1342T+ -40C to +85C 8 TDFN-EP* 12.5 DS1341/DS1342 DS1342T+T&R -40C to +85C 8 TDFN-EP* 12.5 GND +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. *EP = Exposed pad. 19-4998 Rev 3 4/152 DS1341/DS1342 Low-Current I C RTCs for High-ESR Crystals Absolute Maximum Ratings Voltage Range on Any Pin Relative to Ground ....-0.3V to +6.0V Storage Temperature Range ............................ -55C to +125C Operating Temperature Range ........................... -40C to +85C Lead Temperature (soldering, 10s) .................................+300C Junction Temperature Maximum .....................................+150C Soldering Temperature (reflow) .......................................+260C Package Thermal Characteristics (Note 1) SOP TDFN Junction-to-Ambient Thermal Resistance ( ) .....206.3C/W Junction-to-Ambient Thermal Resistance ( ) ..........41C/W JA JA Junction-to-Case Thermal Resistance ( ) ...............42C/W Junction-to-Case Thermal Resistance ( ) .................8C/W JC JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. 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. DC Electrical Characteristics (V = +1.8V to +5.5V, T = -40C to +85C, unless otherwise noted.) (Note 2) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V Full operation (Note 3) 1.8 5.5 CC Operating Voltage Range V V Timekeeping (Notes 3, 4) 1.3 5.5 CCT Minimum Timekeeping Voltage V T = +25C (Notes 3, 4) 1.15 1.3 V CCTMIN A V = +3.0V, EGFIL = 0, DOSF = 1 220 500 CC Timekeeping Current: DS1341 V = +5.5V 250 600 CC CLKIN = GND or CLKIN = V I nA CC CCT V = +3.0V, EGFIL = 1, DOSF = 0 280 560 CC (Note 4) V = +5.5V 320 700 CC V = +3.0V, EGFIL = 0, DOSF = 1 250 600 CC Timekeeping Current: DS1342 V = +5.5V 280 700 CC CLKIN = GND or CLKIN = V I nA CC CCT V = +3.0V, EGFIL = 1, DOSF = 0 310 660 CC (Note 4) V = +5.5V 350 800 CC 0.7 x V + CC Logic 1 Input V (Note 2) V IH V 0.3 CC 0.3 x Logic 0 Input V (Note 2) -0.3 V IL V CC Input Leakage I ECLK = 1, V = 0V to V -0.1 +0.1 A LI IN CC (SCL, CLKIN/INTA) Output Leakage I ECLK = A1IE = A2IE = 0 -1.0 +1.0 A O (CLKIN/INTA, SQW/INTB) V 1.8V, INTCN = 0 -3.0 mA Output Logic 1 CC I OH V = +1.0V (SQW/INTB) V 1.3V, INTCN = 0 -250 A OH CC Output Logic 0 V 1.8V 3.0 mA CC V = +0.4V (SDA, CLKIN/INTA, I OL OL V 1.3V (Note 5) 250 A SQW/INTB) CC Maxim Integrated 2 www.maximintegrated.com