PCF2127A
Overview
The PCF2127A is a CMOS1 Real Time Clock (RTC) and calendar with an integrated Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and very low power consumption. The PCF2127A has 512 bytes of general purpose static RAM, a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features.
- Features and benefits * * * * *
- Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors Typical accuracy: ±3 ppm from -15 °C to +60 °C Integration of a 32.768 kHz quartz crystal and oscillator in the same package Provides year, month, day, weekday, hours, minutes, and seconds 512 bytes of general purpose static RAM Timestamp function
- with interrupt capability
- detection of two different events on one multilevel input pin (e.g. for tamper detection) Two line bidirectional 400 kHz Fast-mode I2C-bus interface (IOL = 3 mA at pin SDA/CE) 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 pin 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 and system reset pin (open-drain) Programmable 1 second or 1 minute interrupt Programmable countdown timer with interrupt capability Programmable watchdog timer with interrupt and reset capability Programmable alarm function with interrupt capability Programmable square wave open-drain output pin Clock operating voltage: 1.2 V to 4.2 V Low supply current: typical 0.65 μA at VDD = 3.0 V and Tamb = 25 °C * * * * * * * * * * * * * * * *
- The definition of the abbreviations and
