DS1305 Serial Alarm Real-Time Clock BENEFITS AND FEATURES PIN CONFIGURATIONS Completely Manages All Timekeeping TOP VIEW Functions V 1 20 V CC2 CC1 o Real-Time Clock (RTC) Counts Seconds, V 2 19 N.C. BAT Minutes, Hours, Date of the Month, DS1305 X1 3 18 PF Month, Day of the Week, and Year with N.C. 4 17 V CCIF Leap-Year Compensation Valid Up to X2 5 16 SD0 2100 N.C. 6 15 SDI o 96-Byte, Battery-Backed NV RAM for INT0 7 14 SCLK Data Storage N.C. 8 13 N.C. o Two Time-Of-Day Alarms, INT1 9 12 CE Programmable on Combination of GND 10 11 SERMODE Seconds, Minutes, Hours, and Day of the Week TSSOP (4.4mm) Standard Serial Port Interfaces with Most V 1 16 V CC2 CC1 Microcontrollers V 2 15 PF BAT o Supports SPI (Serial Peripheral Interface) DS1305 X1 3 14 V CCIF Modes 1 and 3 or Standard 3-Wire X2 4 13 SDO Interface N.C. 5 12 SDI o Burst Mode for Reading/Writing INT0 6 11 SCLK Successive Addresses in Clock/RAM INT1 7 10 CE GND 8 9 SERMODE Multiple Power Supply Pins Ease Adding Battery For Backup DIP (300 mils) o Dual-Power Supply Pins for Primary and Backup Power Supplies o Optional Trickle Charge Output to TYPICAL OPERATING CIRCUIT Backup Supply o 2.0V to 5.5V Operation 20-Pin TSSOP Minimizes Required Space Optional Industrial Temperature Range: -40C to +85C Supports Operation in a Wide Range of Applications Underwriters Laboratory (UL) Recognized UL is a registered trademark of Underwriters Laboratories Inc. 19-5055 Rev 4/15 1 of 22 DS1305 ORDERING INFORMATION PART TEMP RANGE PIN-PACKAGE TOP MARK* DS1305 0C to +70C 16 DIP (300 mils) DS1305 DS1305N -40C to +85C 16 DIP (300 mils) DS1305N DS1305E 0C to +70C 20 TSSOP (173 mils) DS1305 DS1305E+ 0C to +70C 20 TSSOP (173 mils) DS1305 DS1305E/T&R 0C to +70C 20 TSSOP (173 mils) DS1305 DS1305E+T&R 0C to +70C 20 TSSOP (173 mils) DS1305 DS1305EN -40C to +85C 20 TSSOP (173 mils) DS1305 DS1305EN+ -40C to +85C 20 TSSOP (173 mils) DS1305N DS1305EN/T&R -40C to +85C 20 TSSOP (173 mils) DS1305 DS1305EN+T&R -40C to +85C 20 TSSOP (173 mils) DS1305 +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. *An N on the top mark denotes an industrial device. DESCRIPTION The DS1305 serial alarm real-time clock provides a full binary coded decimal (BCD) clock calendar that is accessed by a simple serial interface. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. In addition, 96 bytes of NV RAM are provided for data storage. The DS1305 will maintain the time and date, provided the oscillator is enabled, as long as at least one supply is at a valid level. An interface logic power-supply input pin (V ) allows the DS1305 to drive SDO and pins to a level PF CCIF that is compatible with the interface logic. This allows an easy interface to 3V logic in mixed supply systems. The DS1305 offers dual-power supplies as well as a battery input pin. The dual power supplies support a programmable trickle charge circuit that allows a rechargeable energy source (such as a super cap or rechargeable battery) to be used for a backup supply. The V pin allows the device to be backed up by BAT a non-rechargeable battery. The DS1305 is fully operational from 2.0V to 5.5V. Two programmable time-of-day alarms are provided by the DS1305. Each alarm can generate an interrupt on a programmable combination of seconds, minutes, hours, and day. Dont care states can be inserted into one or more fields if it is desired for them to be ignored for the alarm condition. The time-of- day alarms can be programmed to assert two different interrupt outputs or to assert one common interrupt output. Both interrupt outputs operate when the device is powered by V , V , or V . CC1 CC2 BAT The DS1305 supports a direct interface to SPI serial data ports or standard 3-wire interface. A straightforward address and data format is implemented in which data transfers can occur 1 byte at a time or in multiple-byte-burst mode. 2 of 22