NXP Real-Time Clocks

NXP's broad portfolio of tiny, full-featured real-time clocks deliver higher accuracy and lower power consumption to a variety of end applications. From battery management and alarm to time-stamp and tamper detect functionality, RTCs from NXP offer a wide range of features for your system. Automotive compliant AEC-Q100 devices are also available.

Ultra-Low
Power
Temperature Compensated with
Integrated Crystal
AEC-Q100
Qualified

Ultra-Low-Power

NXP’s ultra-low-power RTC’s provide the low power consumption that enables long battery life with regard to real-time clock functionality. PCF2123 and PCF8523 are optimized for energy critical applications. The PCF85063 devices come in tiny packages at very competitive prices. PCF85263 and PCF85363 offer an energy-efficient, autonomous timing circuit with time stamp, battery back-up, two alarms, and resolution up to 1/100 s solution. Devices are available with I2C or SPI bus interfaces.

Device Number	Key Features	Bus
PCF85263	Battery back-up switch and time stamp	I²C	Expand to Learn More
The NXP PCF85263 is a CMOS real-time clock (RTC) and calendar, optimized for low power consumption, that switches automatically to battery power when main power is lost. The PCF85263 can be configured as a stopwatch (or elapsed-time counter) with a resolution of up to 1/100 s. Three time stamps make it easy to register special events, and the device can also register tamper detection or time of battery switchover. A sophisticated battery backup circuit improves power efficiency. The circuit makes it possible to use a battery with a nominal voltage that is higher or lower than the regular supply voltage. For example, in a system that uses a V_DD of 3 V, a lithium battery of 4.2 V can be used as a backup. Key Features Multiple operating modes Clock (seconds to 99 years) Stopwatch or elapsed-time counter (1/100 s to 999 999 h) Watchdog in parallel Battery input voltage can be lower or higher than VDD Time-stamp input, three time-stamp registers Two independent alarms Electronic frequency tuning via command Large clock operating voltage range (0.9 to 5.5 V) Ideal for battery-backed operation (IDD= ~0.27 μA) 400 kHz two-line I²C interface (at VDD = 1.8 to 5.5 V) TSSOP8, TSSOP10, SO8, and tiny DFN2626 package Applications Printers, copiers Electronic metering TVs, Blu-Ray players, projectors, etc. Digital cameras White goods Accurate, high-duration timers Data loggers
PCF85363	Battery back-up switch, time stamp, and RAM	I²C	Expand to Learn More
The NXP PCF85363 is a CMOS real-time clock (RTC) and calendar, optimized for low power consumption, that switches automatically to battery power when main power is lost. The PCF85363 can be configured as a stopwatch (or elapsed- time counter) with a resolution of up to 1/100 s. Three time stamps make it easy to register special events, and the device can also register tamper detection or time of battery switchover. The integrated RAM block of 64 Bytes is ideal for storing parameters during system power-down. The battery keeps the RTC running and maintains memory content. A sophisticated battery-backup circuit improves power efficiency. The circuit makes it possible to use a battery with a nominal voltage that is higher or lower than the regular supply voltage. For example, in a system that uses a V_DD of 2.5 V, a lithium battery of 3 V can be used as a backup. Key Features Multiple operating modes Clock (seconds to 99 years) Stopwatch or elapsed-time counter (1/100 s to 999 999 h) Watchdog in parallel Battery input voltage can be higher or lower than V_DD Time-stamp input with three time-stamp registers 64 Bytes of general-purpose RAM (battery-buffered) Two independent alarms Electronic frequency tuning via command Large clock operating voltage range (0.9 to 5.5 V) Ideal for battery-backed operation (I_DD= ~0.27 μA) 400 kHz two-line I²C-bus interface (at V_DD = 1.8 to 5.5 V) TSSOP8, TSSOP10, and tiny DFN2626 package Applications Inkjet and laser printers Digital still and video cameras Handheld and mobile devices Industrial equipment Home automation Alarm systems Self-care medical devices Eco-friendly heating control
PCF85063	Miniaturized, state-of-the-art RTC	I²C or SPI	Expand to Learn More
The NXP PCF85063 offers precise timing in a small, low-power format. It is well suited for a wide range of applications. Aside from acting as a reference timer or tracking the actual time and date, the device can be used for power management, where the device wakes the microcontroller from hibernation mode, or as a system reference clock for a PLL input. It can serve as a watchdog or countdown timer, and can be used as an activation timer to start measurements or initiate other functions. The device is available in three versions. The TP version tracks time and date and has an I²C Fast-mode interface. It offers electronic tuning and can be configured for a frequency output and an interrupt every 30 or 60 seconds. It is housed in a HWSON8 that measures only 2 x 3 x 0.8 mm. The -A and -B versions add an alarm facility, a countdown timer, and a clock-out enable pin. The -A version is equipped with an I2C Fast-mode interface, while the -B has a 3-line SPI interface. Key Features Tiny leadless package with 0.5 mm pitch and 0.5 mm height Time and date from seconds to years Electronic frequency tuning Supports interrupts every 30 or 60 seconds General-purpose RAM byte Clock out from 1 Hz to 32.768 kHz Oscillator for low power quartz (CL = 7 pF) Wide operating voltage range, VDD = 0.9 to 5.5 V Ideal for battery-powered operation IDD = ~0.2 μA HWSON8, SO8, TSSOP8, DFN2626-10 package options Applications Ink and laser printers Self-care medical devices Digital still cameras Digital video cameras Hand held and mobile devices Gaming, toys Industrial equipment Home automation Alarm systems
PCF8523	Optimized for energy-critical applications	I²C	Expand to Learn More
The PCF8523 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption. Data is transferred serially via an I²C-bus with a maximum data rate of 1000 kbit/s. Alarm and timer functions are available with the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine-tuning of the clock. The PCF8523 has a backup battery switch-over circuit, which detects power failures and automatically switches to the battery supply when a power failure occurs. Key Features Ultra low power consumption: 120 nA @ 3 V Clock operating voltage: 1.2 V to 5.5 V 2 line bi-directional 1 MHz Fast-mode Plus I²C interface Battery backup input pin and switch-over circuitry Integrated oscillator load capacitors for CL = 7 and 12.5 pF Second countdown timer with interrupt output Applications Time keeping application Battery powered devices Metering High duration timers Daily alarms Low standby power applications
PCF2123	Optimized for low-cost, energy-critical applications	SPI	Expand to Learn More
The PCF2123 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power applications. Data is transferred serially via a Serial Peripheral Interface (SPI-bus) with a maximum data rate of 6.25 Mbit/s. An alarm and timer function is also available providing the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine tuning of the clock. Key Features Ultra low power consumption: 100 nA @ 2 V Clock operating voltage: 1.1 to 5.5 V 3-line SPI with separate, combinable data I/O Serial interface (at V_DD = 1.6 to 5.5 V) Free programmable timer and alarm with interrupt capability Integrated oscillator load capacitors for C_L = 7 pF Applications Time keeping application Battery powered devices Metering High duration timers Daily alarms Low standby power applications

Temperature Compensated with Integrated Crystal

NXP’s CMOS RTC’s with calendar with an integrated quartz crystal (Xtal) oscillator (TCXO) are optimized for very high accuracy and low power consumption for industrial applications. The devices sense temperature and make internal adjustments to ensure accurate time keeping over temperature range. Pin selectable I²C bus or SPI bus. PCF2127/A includes 512 bytes of general-purpose static RAM.

Device Number	Key Features	Bus
PCF2127	Integrated quartz crystal for industrial applications	I²C or SPI	Expand to Learn More
The PCF2127 is a CMOS 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 PCF2127 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. Key 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 year correction Applications 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
PCF2129	Integrated quartz crystal for industrial applications	I²C or SPI	Expand to Learn More
The PCF2129 is a CMOS 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 PCF2129 has a selectable I²C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features. Key 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 year correction Applications 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
PCA2129	Automotive accurate RTC with integrated quartz crystal	I²C or SPI	Expand to Learn More
The PCA2129 is a CMOS 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 PCA2129 has a selectable I²C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features. Key Features AEC-Q100 grade 2 compliant for automotive applications Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal Low current; typical 0.25 μA at VDD = 3.0 V and Tamb= 25 °C Programmable clock output for peripheral devices (32.768 kHz, 16.384 kHz, 8.192 kHz, 4.096 kHz, 2.048 kHz, 1.024 kHz, and 1 Hz) Alarm function Minute and half minute interrupt Applications 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

AEC-Q100 Qualified

NXP’s automotive RTC’s are designed for highest reliability and lowest power consumption. Devices are available with I2C or SPI bus interfaces. They have an extended operating temperature range of up to 125º C and AEC-Q100 automotive-compliant qualification.

Device Number	Key Features	Bus
PCA85063	Tiny Real-Time Clock/calendar with alarm function	I²C	Expand to Learn More
The PCA85063A is a CMOS1 Real-Time Clock (RTC) and calendar optimized for low power consumption. An offset register allows fine-tuning of the clock. All addresses and data are transferred serially via the two-line bidirectional I2C-bus. Maximum data rate is 400 kbit/s. The register address is incremented automatically after each written or read data byte. Key Features AEC-Q100 grade 2 compliant for automotive applications Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal Low current; typical 0.25 μA at VDD = 3.0 V and Tamb= 25 °C Programmable clock output for peripheral devices (32.768 kHz, 16.384 kHz, 8.192 kHz, 4.096 kHz, 2.048 kHz, 1.024 kHz, and 1 Hz) Alarm function Minute and half minute interrupt Applications Tracking time of the day Accurate timing Dashboard Infotainment unit Air condition Center stack Telematics Body control and battery management
PCA8565	Real-Time Clock and calendar	I²C	Expand to Learn More
The PCA8565 is a CMOS real time clock and calendar optimized for low power consumption. A programmable clock output, interrupt output and voltage-low detector are also provided. All address and data are transferred serially via a two-line bidirectional I²C-bus. Maximum bus speed is 400 kbit/s. The built-in word address register is incremented automatically after each written or read data byte. Key Features AEC-Q100 compliant (PCA8565TS) for automotive applications Provides year, month, day, weekday, hours, minutes and seconds based on a 32.768 kHz quartz crystal Clock operating voltage: 0.9 V to 5.5 V at room temperature Extended operating temperature range: -40 °C to +125 °C Low current; typical 0.65 μA at VDD = 3.0 V and Tamb= 25 °C 400 kHz two-wire I²C-bus interface (at VDD = 1.8 V to 5.5 V) Applications Automotive Industrial Other applications that require a wide operating temperature range
PCA21125	Real-Time Clock and calendar	SPI	Expand to Learn More
The PCA21125 is a CMOS Real-Time Clock (RTC) and calendar optimized for low-power consumption and an operating temperature up to 125 °C. Data is transferred via a Serial Peripheral Interface (SPI-bus) with a maximum data rate of 6.0 Mbit/s. Alarm and timer functions are also available with the possibility to generate a wake-up signal on the interrupt pin. Key Features AEC Q100 compliant for automotive applications Provides year, month, day, weekday, hours, minutes, and seconds based on 32.768 kHz quartz crystal Resolution: seconds to years Clock operating voltage: 1.3 V to 5.5 V Low supply current: typical 0.8 μA at Tamb = 25 °C 4-line SPI-bus with separate, but combinable data input and output Applications Automotive time keeping Metering
PCA2129	Automotive accurate RTC with integrated quartz crystal	I²C or SPI	Expand to Learn More
The PCA2129 is a CMOS 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 PCA2129 has a selectable I²C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features. Key Features AEC-Q100 grade 2 compliant for automotive applications Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal Low current; typical 0.25 μA at VDD = 3.0 V and Tamb= 25 °C Programmable clock output for peripheral devices (32.768 kHz, 16.384 kHz, 8.192 kHz, 4.096 kHz, 2.048 kHz, 1.024 kHz, and 1 Hz) Alarm function Minute and half minute interrupt Applications 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