Module operating voltage: 3.3V / 5V can be connected with 5V or 3.3V microcontroller; Operating temperature: 0~ 70'C - DS1302 main performance index - The real time clock has the ability of calculating prior to the 2100 second minute hour day week month year and the ability to adjust a leap year -Wide working voltage: 2.0~5.5 V - When The working voltage is 2.0V the current is less than 300nA - Read/write clock or RAM data have two transmission way: Single-byte / many bytes group - 8 feet DIP assembly or optional 8 feet SOIC encapsulation according to surface assembly - Simple 3 line interface Pin definitions: VCC: +5V/3.3V GND: GND CLK: P02 DAT: P01 RST: P00