Eindhoven, Netherlands NXP Semiconductors has claimed the industry's best low-power performance real-time clock (RTC) chips with a SPI bus interface. Operating at a current of less than 100 nanoAmps (0.15 uW) on a 1.5-V power supply, the PCF2123 real-time clock, housed in a 3 x 3 x 1-mm package, is well-suited for battery-operated and handheld devices to keep track of time, when the equipment is powered down.
The PCF2123 is a CMOS real-time clock and calendar optimized for low-power consumption. It functions as the time manager accurately keeping time, controlling the periodic wake-up of the microcontroller core from hibernation mode, and providing a watchdog function to independently monitor microcontroller tasks. With power consumption at less than 0.15 uW the RTC can be powered by a very small battery cell or a small supercapacitor.
Key features include a freely programmable alarm and timer function and a programmable offset register. The seconds, minutes, hours, days, weekdays, months and years registers are all coded in binary-coded decimal (BCD) format for easy conversion to decimal digits for printing or display and faster decimal calculations. Data is transferred serially via an SPI bus with a maximum data rate of 6.25 Mbits/s.
Applications include home-use medical devices such as blood pressure monitors, portable phones, PDAs and similar compact portable electronics products where space and power are critical. Other uses include industrial systems as well as white goods.
Pricing: U.S. pricing is $0.55 in high volumes.
Availability: Samples are available now. Volume shipping begins in Q2 2008.
NXP Semiconductors , www.nxp.com