FRTC4111S

FRTC4111S is a low-power serial RTC with 56 bytes of NVRAM. It integrates a 32.768 kHz oscillator (controlled by an external crystal). The first 8 bytes of RAM are used for clock/calendar functions and are configured in BCD format. Address and data are transferred serially via a two-wire bidirectional bus. The built-in address register auto-increments after each write or read of a data byte. The FRTC4111S features an integrated power-fail detection circuit that automatically switches to battery backup upon power failure. The energy required to maintain RAM and 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

• Portable instruments
• Electronic metering
• Battery-powered products
• Telecommunications equipment

Key features

• Seconds, minutes, hours, day, date, month, year, and century counters
• 32 kHz crystal oscillator with integrated load capacitance (12.5 pF) for excellent oscillator stability and high crystal series performance
• Serial interface supporting I²C bus (400 kHz protocol)
• Ultra-low battery supply current 0.4 µA (typical at 3V)
• 2.0 to 5.5 V clock operating voltage
• Automatic switchover and deselect circuitry
• 56-byte general-purpose RAM
• Software clock calibration to compensate for crystal deviation due to temperature
• Automatic leap year compensation
• Operating temperature: -40 to 85℃