Precision RTC Module with I2C Interface for Timekeeping and Memory Applications

Low-cost, highly accurate I2C real-time clock (RTC) with integrated temperature-compensated crystal oscillator (TCXO) and crystal. Features battery input to maintain accurate timekeeping when main power is disconnected. Integrated oscillator improves long-term accuracy and reduces component count. Available in commercial and industrial temperature ranges; packaged in a 16-pin 300-mil SOIC. Maintains seconds, minutes, hours, day, date, month, and year information. Automatically adjusts for months with fewer than 31 days, including leap year correction. Operates in either 24-hour or 12-hour format with AM/PM indicator. Includes two configurable alarms and a programmable square-wave output. Address and data transferred serially via I2C bidirectional bus. Precision temperature-compensated voltage reference and comparator monitor VCC to detect power failure, provide reset output, and automatically switch to backup power. /RST pin supports manual microprocessor reset. Integrated digital temperature sensor accessible via I2C interface (same bus as time data); accuracy ±3°C. On-chip power supply control circuit automatically detects and manages main and backup power sources (e.g., low-voltage battery). Continues accurate timekeeping and temperature measurement during main power failure. On-chip reset function restarts the system microprocessor when main power is restored or voltage returns to the valid range. Module specifications: Size: 38 mm (L) × 22 mm (W) × 14 mm (H) Operating voltage: 3.3 V to 5.5 V RTC chip: DS3231 Clock accuracy: ±2 ppm from 0°C to 40°C (approximately ±1 minute per year) Calendar and alarm functions with two alarms Programmable square-wave output Real-time clock generator for seconds, minutes, hours, day, date, month, and year; valid through year 2100 with leap-year compensation Integrated temperature sensor with ±3°C accuracy Memory chip: AT24C32 (32 Kbit EEPROM) I2C interface with maximum speed of 400 kHz (at 5 V) Supports I2C bus addressing via A0/A1/A2 pins; default address 0x57 Includes rechargeable LIR2032 battery to maintain timekeeping during power loss Standard I2C pinout: SCL → A5, SDA → A4, VCC → 5 V, GND → GND Quantity: 1 unit