DS1302Z

The Trickle Charge Timekeeping Chip contains an RTC/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface. The RTC/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 an AM/PM indicator. Interfacing with a microprocessor is simplified by using synchronous serial communication. Only three wires are required to communicate with the clock/RAM: 1) RST (reset), 2) I/O (data line), and 3) SCLK (serial clock). Data can be transferred to and from the clock/RAM 1 byte at a time or in a burst of up to 31 bytes. It is designed to operate on very low power and retain data and clock information on less than 1 microwatt. It is available in standard SOP8 package.

Applications

• Clock Chip
• Mobile Telephone
• Portable Instruments

Key features

• Real-time clock (RTC) counts seconds, minutes hours, date of the month, month, day of the week, and year with leap-year compensation valid up to 2100
• 31-byte, battery-backed, nonvolatile (NV) RAM for data storage
• Serial I/O for minimum pin count
• 2.0V to 5.5V full operation
• Uses less than 300nA at 2.0V
• Burst mode for reading/writing successive addresses in clock/RAM
• Simple 3-wire interface
• TTL-compatible (VCC = 5Va)
• Optional temperature range: 0°C to +70°C