PCF8566T

PCF8566T is an I2C real-time clock/calendar IC from NXP (Philips) used to keep accurate time in embedded systems.
Key points
- Timekeeping: seconds, minutes, hours, day, date, month, year with leap-year handling; supports 12/24-hour modes.
- Alarm and timer: configurable alerts and timing functions.
- Clock source: external 32.768 kHz crystal; designed for low power.
- Power backup: battery/supercapacitor backup with a trickle-charge circuit to maintain time when main power is off.
- Interface and use: register-based I2C interface; typically low-voltage operation suitable for many microcontroller projects.
- Applications: digital clocks, data loggers, appliances, consumer electronics, industrial controllers.
Notes
- Check the datasheet for exact I2C address, register map, voltage range, packaging, and any variant-specific features.

Do you mean PCF8566T (exact part) or PCF8563T (common I²C RTC)? I don’t want to give incorrect substitutes—please confirm the chip’s function/package or paste its datasheet link and I’ll list direct equivalents (manufacturers and cross‑references) concisely.

Here are the typical features of the PCF8566T (RTC/Calendar with I2C):
- I2C-bus real-time clock/calendar
- 32.768 kHz crystal oscillator input
- Battery-backed operation with automatic VBAT switchover
- 12/24-hour timekeeping; BCD data format; leap-year handling
- Full calendar: seconds, minutes, hours, day, date, month, year
- Alarm functions and a programmable timer
- Programmable square-wave output
- Battery-backed RAM/non-volatile storage for data
- Interruption output with configurable polarity
- I2C interface up to 400 kHz
- Operating voltage: 2.0–5.5 V
- Low-power modes; suitable for wide temperature range
- Packages: 8-pin (e.g., SO8/SOIC)
Note: exact RAM size and certain pin-dedicated functions can vary by package variant; consult the datasheet for the specific 8-pin option you plan to use.

The PCF8566T is manufactured by NXP Semiconductors (originally Philips Semiconductors). NXP is a Dutch multinational semiconductor company that designs and manufactures integrated circuits and system solutions—covering microcontrollers, analog/mixed-signal ICs, RF/connectivity, security, and power devices—serving automotive, industrial, IoT, mobile and communications markets.

PCF8566T is an I2C real-time clock/calendar IC optimized for low-power timekeeping. Common applications:
- Timekeeping, scheduling, and time stamping in microcontroller-based products
- Alarm, wake-up, and periodic interrupt generation for low-power systems
- Data logging and metering with event timestamps
- Automotive dashboards and instrument clusters
- Consumer electronics (appliances, wearables, set-top boxes)
- Industrial and building automation controllers
- Medical portable devices and sensors
- IoT nodes requiring an accurate time base

The "T" in PCF8566T denotes tape-and-reel packaging for automated assembly. The exact physical package (pin count/type and case outline) is specified in the manufacturer's datasheet—check the NXP/Philips PCF8566 datasheet for the precise package variant and dimensions.