Cart

Shop / Accessories

PCF8563 Low-Power RTC

ET-A12

PCF8563 Low-Power RTC

Real-time clock using only 0.25 µA, Qwiic

AED 15.00

Out of stock
✓ TestedEvery board is checked before it ships
🚚 Fast shippingUAE 1–3 days · GCC & worldwide
💬 Engineer supportQuestions answered by the designers

Download datasheet (PDF)

OverviewKey featuresSpecificationsPerformancePinout

Overview

Real-time clock using only 0.25 µA, Qwiic

The ET-A12 is built around the NXP PCF8563 — 0.25µA timekeeping, alarm, timer, programmable clock out. It talks over I2C 0x51.

Two Qwiic / STEMMA QT connectors let you chain it with other boards without soldering, and the 2.54 mm header fits a breadboard.

Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.

Good for

  • Battery loggers
  • Alarm wake-ups
  • Budget clocks

Key features

What makes it different

RTC

NXP PCF8563: 0.25µA timekeeping, alarm, timer, programmable clock out

Accuracy

Crystal-limited ±20ppm (≈1 min/month)

Interface

I2C 0x51

Backup

CR1220 via diode-OR

Qwiic / STEMMA QT

Two JST-SH connectors plus a 2.54 mm header — 3.3 V and 5 V hosts.

Open documentation

Schematic, BOM and layout notes published for every board.

Specifications

Technical specifications

Device
RTCNXP PCF8563: 0.25µA timekeeping, alarm, timer, programmable clock out
AccuracyCrystal-limited ±20ppm (≈1 min/month)
InterfaceI2C 0x51
BackupCR1220 via diode-OR
Board
Size25.4 × 20.3 mm
Mounting2 mounting holes (M2.5)
Connectors2 × Qwiic / STEMMA QT (JST SH 4-pin) · 6-pin 2.54 mm header
Main ICPCF8563TS/5,118 (LCSC C27397)
RevisionRev A
Software
LibrariesRTClib (PCF8563), ESPHome pcf8563
Solder jumpers
JP1 (default Closed)Cut to turn off the LED
JP2 (default Closed)Cut to remove the host-side I2C pull-ups

Performance

Power

Timekeeping currentDatasheet typical battery currents.

Pinout

Pin map and connections

PCF8563 Low-Power RTC pinout: VIN, GND, SCL, SDA, INT, CLKOUT
PinNameTypeFunction
1VINPowerSensor supply = host logic level
2GNDGroundGround
3SCLI²CI²C clock
4SDAI²CI²C data
5INTOutputAlarm/timer, open-drain
6CLKOUTOutput32k/1k/32/1Hz, open-drain

Qwiic / STEMMA QT pins: GND, VIN, SDA, SCL (same on both connectors). I²C pull-ups (10 kΩ) are on the board; cut JP2 to remove them.

Mechanical

Dimensions and what's in the box

Board 25.4 × 20.3 mm with M2.5 holes
Top view · 25.4 × 20.3 mm

In the box

  • 1 × ET-A12 PCF8563 Low-Power RTC (assembled)
  • 1 × 6-pin 2.54 mm male header, unsoldered

Getting started

  • Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
  • Libraries: RTClib (PCF8563), ESPHome pcf8563
  • Run an I²C scanner to confirm the address: 0x51

Compare

Which real-time clock?

PCF8563 Low-Power RTC (this board)This boardET-A11 DS3231 Precision RTC
What it doesReal-time clock using only 0.25 µA, Qwiic±2 ppm temperature-compensated clock with coin-cell backup, Qwiic
InterfaceI²C 0x51I²C fixed 0x68
Best forBattery loggersClocks that keep time for years
Price15 AED39 AED

Downloads

Documents and design files

PDFET-A12 schematicRev ALCSCPCF8563TS/5,118 datasheet and stockC27397
STEP3D modelComing soon

Need a custom version of this board?

Different connector, size or sensor? We design and build custom variants.

Get a design quote Talk to an engineer