Any RTC recommendation?

[wanchope]

Hi, all,
Please kindly recommend any RTC you tested before that is cheap(around 1US$), i2c interfacing, 8 pins, <=3 volt VCC, <=1 volt battery backup?
Thanks.
Wanchope

 

[cesare]

Both Philips and STM has several chip that matches your requirements. STM provides also solutions with integrated battery and crystal.

 

[sp]

i would recommend the DS1302... use it wth uC like PIC is so easy but no build in battery and crystal...


regards,
sp

 

[kupper]

Hi Try searching for Richol, their rtc are used in alot of machines
Spi, i2c interface ...
heard its cheap too ;-)

 

[Jack// ani]

i would recommend the DS1302... use it wth uC like PIC is so easy but no build in battery and crystal...
sp

Do those build in battery need charging.....how long is its backup time!!

 

[kupper]

Sorry typo
Check this link
https://www.ricoh.com/LSI/product_rtc/

 

[dainis]

STMicroelectronics M41T11
https://www.st.com/stonline/books/pdf/docs/6103.pdf

FEATURES SUMMARY
■ 2.0 TO 5.5V CLOCK OPERATING VOLTAGE
■ COUNTERS FOR SECONDS, MINUTES,
HOURS, DAY, DATE, MONTH, YEARS AND
CENTURY
■ YEAR 2000 COMPLIANT
■ SOFTWARE CLOCK CALIBRATION
■ AUTOMATIC SWITCH-OVER AND
DESELECT CIRCUITRY
■ I2C BUS COMPATIBLE
■ 56 BYTES of GENERAL PURPOSE RAM
■ ULTRA-LOW BATTERY SUPPLY CURRENT
OF 1µA
■ LOW OPERATING CURRENT OF 300µA
■ BATTERY OR SUPER-CAP BACK-UP
■ BATTERY BACK-UP NOT RECOMMENDED
FOR 3.0V APPLICATIONS (CAPACITOR
BACK-UP ONLY)
■ OPERATING TEMPERATURE OF –40 TO
85°C
■ AUTOMATIC LEAP YEAR COMPENSATION
■ SPECIAL SOFTWARE PROGRAMMABLE
OUTPUT

 

[e_eja]

to get low cost RTC tou must order in large quantity, otherwise you wouldnot be abble to have it,
try RTC on old computer, some used DS12C887 but this not IIC interface, and you migh have it freely
regards