FRTC4100S

The FRTC4100S is a low-power serial real-time clock (RTC). It incorporates a built-in 32.768kHz oscillator (controlled by an external crystal). The first 8 bytes of RAM are used for clock/calendar functions and are configured in binary-coded decimal (BCD) format. Addresses and data are transferred serially via a two-wire bidirectional bus. The built-in address register automatically increments after each byte write or read operation. The FRTC4100S clock features an integrated power detection circuit that monitors power supply status and automatically switches to battery backup upon power failure. The energy required to maintain clock operation can be supplied by a small lithium coin cell battery. With a 50 mA/h, 3V lithium battery, typical data retention exceeds 5 years.

Applications

• Real-time clock applications
• Battery-powered devices
• Industrial control
• Consumer electronics
• Communication equipment

Key features

• 2.0 to 5.5V clock supply voltage
• Seconds, minutes, hours, day, date, month, year, and century counters
• Year 2000 compliant
• Software clock calibration to compensate for crystal deviation due to temperature
• Automatic switchover and deselect circuit
• Serial interface supporting I²C bus (400 kHz protocol)
• Ultra-low battery backup current 0.4 μA (typical at 3V)
• Low operating current 150 μA
• Supercapacitor backup battery
• 32 kHz crystal oscillator with integrated load capacitance (12.5 pF) for excellent oscillator stability and high crystal series
• Special software-programmable output
• Automatic leap year compensation
• Operating temperature –40 to 85℃