NXP Semiconductors PCF85053A CMOS Real-Time Clock (RTC)
NXP Semiconductors PCF85053A CMOS Real-Time Clock (RTC) is optimized for low power consumption and automatic switching to battery on primary power loss. The NXP Semiconductors PCF85053A features clock output, alert interrupt output, a 128-byte battery backed-up SRAM, and two I2C buses. Its clock output calibration-related registers set the PCF85053A apart from other RTCs, which allows for crystal capacitive load (CL) configuration and offset register setting.
Features
- 1.7V to 3.6V supply voltage
- 1.55V to 3.6V battery supply voltage
- Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768kHz quartz crystal
- Device addresses
- 1101 111 RTC
- 1010 111 SRAM
- Two independent I2C with speed 400kHz max
- I2C clock timeout 35ms max
- Primary I2C bus
- Read/write capability on RTC and SRAM registers
- Active low ALRT (interrupt) output
- Second I2C bus
- Read/write capability on RTC and SRAM registers enabled by primary I2C
- I2C bus not active during battery switchover
- Real-time clock and calendar
- Align to MC146818B register definition for offset 0 to 09h
- Supports both binary mode and BCD mode
- Supports 24-hour and 12-hour mode
- Support daylight saving mode
- Interrupt flag support
- RTC_CLR flag
- Alarm flag
- RTC fail flag
- Oscillator fail flag
- Battery-backed 128-byte SRAM
- SRAM clear to ‘0’ by RTC_CLR Pin
- Frequency adjustment via programmable offset register
- Configurable oscillator circuit for a wide variety of quartzes like CL = 6pF, CL = 7pF, and CL = 12.5pF
- -40°C to 85°C operating temperature range
Applications
- Server and computer precision timekeeping
- Network-powered and industrial electronics
- Products with long automated unattended operation time
- White goods
Block Diagram
Evaluation Board
NXP Semiconductors PCF85053ATK-ARD Evaluation Board
Used to test and evaluate the functions and performances of the PCF85053A CMOS Real-Time Clock.
Published: 2023-05-09
| Updated: 2023-05-12