NXP RTC Demo PCF2123

Future Designs and Digi-Key introduce the Real Time Clock Demo for PCF2123

Future Designs, Inc. RTC Demo PCF2123 Image

The NXP RTC Demo PCF2123 is a reference design for a low power Real Time Clock and LCD solution with an available I2C temperature sensor. The Demo Board is controlled by a simple two-button user interface (MODE and SELECT). Example code for several sample applications: a programmable time and date display, a programmable countdown timer, and a repeating pattern of text lines, can all be found on the Future Designs Inc. website. The user can edit this code and download it the reprogrammable Flash microcontroller via a 10-pin header included on the board using any external ICP style programmer.

Digi-Key P/N	ADI P/N	Description
622-1027-ND	RTC-DEMO-PCF2123	BOARD RTC DEMO PCF2123

Features
PCF2123 / PCA2125 Low Power SPI based RTC
	•	Resolution - sec, minutes, hours, weekday, day, month, year
	•	Operating voltage 1.2 to 5.5V
	•	Low standby current for SuperCap
	•	Three-line SPI with separate data I/O
	•	Programmable timer / alarm functions with interrupt capability
	•	Internal power-on reset
	•	32.768 KHz quartz crystal
LM75B Low Power Temp Sensor
	•	Temperature resolution of 0.125 °C
	•	Pin-for-Pin Replacement for LM75 and LM75A standards
	•	Temperatures range from -55 °C to +125 °C
P89LPC932A1 8-bit, 2-clock, 80C51 MCU
	•	8 KB Flash, 256 bytes RAM
	•	28-pin PLCC package with Internal RC Oscillator
	•	UART, ADC, DAC, two 16-bit timers & RTC, KBI
	•	WDT with on chip 400kHz oscillator

Highlights
	•	Low power, SPI based Real Time Clock driven by a 32.768 KHz quartz crystal
	•	Supports Two Different RTC Options in a TSSOP-14 Package (PCF2123 and PCA2125)
	•	Available Low Power LM75B I2C Temperature Sensor
	•	Powered by a single 3V coin cell battery
	•	8-character alphanumeric LCD
	•	I2C based LCD driver with 128 segment support
	•	Two miniature push-buttons for user control; additional User Interface via header
	•	User reprogrammable via 10-pin ICP header