PCF8583T/5,518

PCF8583T is an I2C-bus Real-Time Clock/Calendar with onboard RAM from Philips/NXP. It keeps time (seconds, minutes, hours, day, date, month, year) in a calendar that supports leap year and offers alarm/timing features. It also provides RAM for data storage and has a battery-backup input to preserve time when main power is removed. Interfaces via a standard I2C connection (7-bit address) and typically comes in an 8-pin package, operating around 2.5–5.5 V. Applications include microcontroller timekeeping, event logging, scheduling, and time stamping. The “T” and “5,518” suffixes denote variants (packaging/temperature or feature differences); exact register maps, RAM size, alarm modes, and timing specifications vary by variant. For precise details, consult the PCF8583T datasheet.

Key features of PCF8583T/5,518 (I2C RTC/Calendar with RAM):
- I2C-bus serial interface (two-wire, compatible with standard and fast modes).
- Real-Time Clock/Calendar: time and date with seconds, minutes, hours, day, date, month, year; leap-year aware.
- 256 x 8 RAM for user data accessible over I2C.
- Alarm/interrupt capability: programmable alarms with an interrupt (INT) output.
- Optional clock output (e.g., 1 Hz square wave) for timing reference.
- Battery-backup operation: VBAT maintains time and RAM during main-power loss.
- Low-power operation and wide supply range (typical 2.5–5.5 V; suitable for battery-powered designs).
- 16-pin package options (DIP/SOIC) for easy integration.
- Simple address auto-incrementing across RAM/RTC registers for easy access.
Notes: Always consult the specific datasheet for exact pinout, voltage range, current consumption, and timing details for the PCF8583T/5,518 variant you’re using.

Pin count: 16 pins (standard 16‑pin package).
Function: I2C real-time clock/calendar with on‑chip RAM (RTC + memory).

Manufacturer: NXP Semiconductors (originally Philips Semiconductors).
Company type: A Dutch multinational corporation that designs and manufactures semiconductors and integrated circuits for automotive, industrial, communications, and consumer electronics.

PCF8583T is an I2C real-time clock/calendar with battery-backed RAM. Suitable for:
- Time stamping, scheduling, and time-triggered control in microcontroller systems
- Data logging and metering (industrial, environmental, utilities)
- Alarm, timer, and wake-up functions in embedded devices
- Consumer electronics with calendar features
- Automotive, telecom, and industrial equipment requiring persistent timebase
- Medical devices needing accurate event timing
- Access control and security systems for event logging
- Any application needing a small, low-power clock plus RAM for nonvolatile data

Package: 16‑pin (DIP‑16 / SO‑16) variant.