描述 Description

The PCF2129 is a CMOS Real Time Clock (RTC) and calendar with an integratedTemperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartzcrystal optimized for very high accuracy and very low power consumption. The PCF2129has a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, aprogrammable watchdog function, a timestamp function, and many other features.

特性 Features

Operating temperature range from -40 °C to +85 °C
Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors
Typical accuracy:PCF2129AT: ±3 ppm from -15 °C to +60 °C
PCF2129T: ±3 ppm from -30 °C to +80 °C
Integration of a 32.768 kHz quartz crystal and oscillator in the same package
Provides year, month, day, weekday, hours, minutes, seconds, and leap yearcorrection
Timestamp function:with interrupt capability
detection of two different events on one multilevel input pin (for example, for tamperdetection)
Two line bidirectional 400 kHz Fast-mode I2C-bus interface
3 line SPI-bus with separate data input and output (maximum speed 6.5 Mbit/s)
Battery backup input pin and switch-over circuitry
Battery backed output voltage
Battery low detection function
Power-On Reset Override (PORO)
Oscillator stop detection function
Interrupt output (open-drain)
Programmable 1 second or 1 minute interrupt
Programmable watchdog timer with interrupt
Programmable alarm function with interrupt capability
Programmable square output
Clock operating voltage: 1.8 V to 4.2 V
Low supply current: typical 0.70 μA at VDD = 3.3 V

應用 Application

Electronic metering for electricity, water, and gas
Precision timekeeping
Access to accurate time of the day
GPS equipment to reduce time to first fix
Applications that require an accurate process timing
Products with long automated unattended operation time