±3.5ppm, IC RTC with Integrated Crystal and Power Management

The MAX31328 is a low-cost, extremely accurate, I2C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input and maintains accurate timekeeping when main power to the device is interrupted. The integration of the crystal resonator enhances the long-term accuracy of the device and eliminates the external crystal requirement in the system. The MAX31328 is available in a 10-pin LGA package.

The RTC maintains seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either 24-hour or 12-hour format with an AM/PM indicator. Two programmable time-of-day alarms and a programmable square-wave output are provided. Address and data are transferred serially through an I2C bidirectional bus. A precision temperature-compensated voltage reference and comparator circuit monitors the status of VCC to detect power failures and automatically switch to the backup supply when necessary. Additionally, the active-low RST pin is monitored as a pushbutton input for generating a microprocessor reset.

Applications

* Global Positioning System * Power Meters * Servers * Telematics

* Highly Accurate RTC with Integrated crystal Resonator Completely Manages All Timekeeping Functions

* Complete Clock Calendar Functionality Including Seconds, Minutes, Hours, Day, Date, Month, Year, and Century with Leap-Year Compensation Up to Year 2100* Low Timekeeping Battery Current of 660nA * Timekeeping Accuracy ±3.5ppm (±0.302 second/day) from -40°C to 85°C * Two Time-of-Day Alarms * Temperature-Compensated Programmable Square-Wave Output * Register for Aging Trim * Active-low RST Output/Pushbutton Reset Debounce Input * Digital Temperature Sensor with ±3°C Accuracy * +2.3V to +5.5V Supply Voltage

* Simple Serial Interface Connects to Most Microcontrollers

* I2C Interface (400kHz)

* Battery-Backup Input for Continuous Timekeeping

* Low-Power Operation Extends Battery-Backup Runtime

* 3.3V Operation

* Operating Temperature Range: -40°C to 85°C * 5mm x 5mm, 10-Pin LGA Package