描述 Description

The PCF2127 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 PCF2127has 512 bytes of general-purpose static RAM, a selectable I2C-bus or SPI-bus, a backupbattery switch-over circuit, a programmable watchdog function, a timestamp function, andmany other features.

特性 Features

UL Recognized Component
Operating temperature range from -40 °C to +85 °C
Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors
Typical accuracy:PCF2127AT: ±3 ppm from -15 °C to +60 °C
PCF2127T: ±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
512 bytes of general-purpose static RAM
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
Extra power fail detection function with input and output pins
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 wave output pin
Programmable countdown timer with interrupt
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