Extremely Accurate SPI Bus RTC DS3234 with Integrated Crystal and SRAM General Description Benefits and Features The DS3234 is a low-cost, extremely accurate SPI bus Highly Accurate RTC with Integrated Crystal and real-time clock (RTC) with an integrated temperature-com- SRAM Completely Manages All Timekeeping pensated crystal oscillator (TCXO) and crystal. The Functions DS3234 incorporates a precision, temperature-compen- Accuracy 2ppm from 0C to +40C sated voltage reference and comparator circuit to monitor Accuracy 3.5ppm from -40C to +85C V . When V drops below the power-fail voltage (V ), CC CC PF Real-Time Clock Counts Seconds, Minutes, Hours, the device asserts the RST output and also disables read Day, Date, Month, and Year, with Leap Year and write access to the part when V drops below both CC Compensation Valid Up to 2099 V and V . The RST pin is monitored as a pushbutton PF BAT Digital Temp Sensor Output: 3C Accuracy input for generating a P reset. The device switches to the Register for Aging Trim backup supply input and maintains accurate timekeeping RST Input/Output when main power to the device is interrupted. The integra- Two Time-of-Day Alarms tion of the crystal resonator enhances the long-term accu- Programmable Square-Wave Output racy of the device as well as reduces the piece-part count in a manufacturing line. The DS3234 is available in com- Simple Serial Interface Connects to Most mercial and industrial temperature ranges, and is offered Microcontrollers in an industry-standard 300-mil, 20-pin SO package. 4MHz SPI Bus Supports Modes 1 and 3 The DS3234 also integrates 256 bytes of battery-backed Battery-Backup Input for Continuous Timekeeping SRAM. In the event of main power loss, the contents of Low Power Operation Extends Battery Backup Run the memory are maintained by the power source con- Time nected to the V pin. The RTC maintains seconds, BAT Operating Temperature Ranges: Commercial: 0C to minutes, hours, day, date, month, and year information. +70C, Industrial: -40C to +85C The date at the end of the month is automatically adjust- 300-Mil, 20-Pin SO Package ed for months with fewer than 31 days, including correc- Underwriters Laboratories (UL) Recognized tions for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. Two Ordering Information programmable time-of-day alarms and a programmable square-wave output are provided. Address and data PIN- TOP PART TEMP RANGE are transferred serially by an SPI bidirectional bus. PACKAGE MARK DS3234S 0C to +70C 20 SO DS3234S Applications DS3234SN -40C to +85C 20 SO DS3234SN Servers Utility Power Meters Telematics GPS Denotes an RoHS-compliant device that may include lead(Pb) that is exempt under the RoHS requirements. Lead finish is JESD97 Category e3, and is compatible with both lead-based and lead-free soldering processes. A anywhere on the top mark denotes an RoHS-compliant device. Typical Operating Circuit V V CC PU V CC V CC SS CS SCLK SCLK INT/SQW MOSI DIN MISO DOUT 32kHz RST RST V BAT P N.C. DS3234 N.C. N.C. PUSH- N.C. N.C. BUTTON N.C. N.C. RESET N.C. N.C. GND Underwriters Laboratories Inc. is a registered certification mark of Underwriters Laboratories Inc. 19-5339 Rev 4 3/15Extremely Accurate SPI Bus RTC DS3234 with Integrated Crystal and SRAM Absolute Maximum Ratings Voltage Range on Any Pin Relative to Ground......-0.3V to +6.0V Junction Temperature......................................................+125C Junction-to-Ambient Thermal Resistance ( ) (Note 1) ...55C/W Storage Temperature Range ...............................-40C to +85C JA Junction-to-Case Thermal Resistance ( ) (Note 1) ........24C/W Lead Temperature (soldering, 10s) .................................+260C JC Operating Temperature Range Soldering Temperature (reflow, 2 times max) ....................+260C (noncondensing) .............................................-40C to +85C (See the Handling, PC Board Layout, and Assembly section.) 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. Recommended Operating Conditions (T = -40C to +85C, unless otherwise noted.) (Notes 2, 3) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V 2.0 3.3 5.5 CC Supply Voltage V V 2.0 3.0 3.8 BAT 0.7 x V + CC Logic 1 Input CS, SCLK, DIN V V IH V 0.3 CC +0.2 x 2.0V V 3.63V -0.3 Logic 0 Input CS, SCLK, DIN, CC V V CC V IL RST 3.63V < V 5.5V -0.3 +0.7 CC Electrical Characteristics (V = 2.0V to 5.5V, V = active supply (see Table 1), T = -40C to +85C, unless otherwise noted.) (Typical values are at V = CC CC CC A 3.3V, V = 3.0V, and T = +25C, unless otherwise noted. TCXO operation guaranteed from 2.3V to 5.5V on V and 2.3V to 3.8V on BAT A CC V .) (Notes 2, 3) BAT PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V = 3.63V 400 SCLK = 4MHz, BSY = 0 CC Active Supply Current I A CCA (Notes 4, 5) V = 5.5V 700 CC CS = V , 32kHz output off, V = 3.63V 120 IH CC Standby Supply Current I A CCS SQW output off (Note 5) V = 5.5V 160 CC V = 3.63V 500 SPI bus inactive, 32kHz CC Temperature Conversion Current I A CCSCONV output off, SQW output off V = 5.5V 600 CC Power-Fail Voltage V 2.45 2.575 2.70 V PF V Leakage Current I 25 100 nA BAT BATLKG (V = 2.0V to 5.5V, T = -40C to +85C, unless otherwise noted.) (Notes 2 and 3) CC A Logic 1 Output, 32kHz V > 3.63V, CC I = -500A 3.63V > V > 2.7V, OH CC V 0.85 x V V OH CC I = -250A 2.7V > (V or V ) > 2.0V OH CC BAT I = -125A (BB32kHz = 1) OH www.maximintegrated.com Maxim Integrated 2