Datasheet

1. General description
The PCA2129T is a CMOS
1
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 PCA2129T
has a selectable I
2
C-bus or SPI-bus, a backup battery switch-over circuit, a
programmable watchdog function, a timestamp function, and many other features.
2. Features and benefits
 AEC-Q100 compliant for automotive applications
 Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors
 Typical accuracy: 3ppm 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 year
correction
 Timestamp function
 with interrupt capability
 detection of two different events on one multilevel input pin (for example, for tamper
detection)
 Two line bidirectional 400 kHz Fast-mode I
2
C-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 A at V
DD
=3.3V
PCA2129T
Accurate RTC with integrated quartz crystal for automotive
Rev. 4 — 11 July 2013 Product data sheet
1. The definition of the abbreviations and acronyms used in this data sheet can be found in Section 20.