The Gravity I2C SD2405 RTC module is an extremely accurate I2C real-time clock (RTC) with crystal compensation and an internal rechargeable battery. It features a dual power supply system that can automatically switch between the main power supply and the battery when the main power drops or recovers from low energy.

The power consumption is 1uA with the internal battery and can operate without external power supply for 5 to 8 years. It is capable of generating periodic interrupt pulses and has three alarm interrupt features per year, month, date, day of the week, hours, and minutes.

It comes with a selectable output clock of 32.768KHz to 1Hz for external MCU and integrates a time adjustment circuit for higher accuracy, compensating for crystal frequency errors. It includes 12 bytes of general SRAM.

As it functions as a data logger and timer, it's an ideal choice for time projects.

• Operating voltage: 3.3V~5.5V
• Low consumption: typically 1uA (internal battery, Ta=25°C)
• Date: Up to 2099 (with leap year compensation)
• Accuracy: ±5ppm from -40°C to +85°C
• Fast I2C interface (400kHz)
• Counts seconds, minutes, hours, day, date, month, and year with leap year compensation up to 2100
• Notifications for day, month, week, hour, minute, and second
• Programmable square wave output: 32768hz, 4096hz, ... 1hz, 1/16hz
• Countdown timer switch
• High precision time adjustment circuit
• Option for 12-hour or 24-hour time display
• Dimensions: 35.50 * 22.00 (mm)
• Weight: 6g