Real Time Clocks

What is a Real Time Clock?

A Real Time Clock (RTC) is a computer clock which is usually in the form of an integrated circuit. They have been designed to keep track of time, in real time - hence the product name. A Real Time Clock is usually an integral part of the computer motherboard. More often than not, an RTC will also include a calendar and an alarm

How do Real Time Clocks work?

The memory on the clocks system stores system descriptions and set up values such as "Current Time Value". The information that is held in the RTC is read with a microprocessor, commonly over a serial interface which facilitates the performance of the software functions that are time dependant.

Designed to run on ultra-low power consumption, RTCs often run on a lithium battery source but can also run on normal power. This power source allows them to continue running and generating real time when a system is down. The newer models of RTC use super-capacitors as a source of power that can be recharged and soldered to the board. Some Real Time Clocks feature synchronisation to an external signal, such as a compensated power line frequency. It allows the device to provide an accurate result without having an on-board temperature compensation scheme.

RTC Time Values

  • Year
  • Month
  • Date
  • Hours
  • Minutes
  • Seconds

...
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Viewing 1 - 20 of 295 products
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Description Price Functions Date Format Time Format User RAM Bus Type Mounting Type Package Type Pin Count Dimensions Length Width Height Maximum Operating Supply Voltage
RS Stock No. 624-8466
Mfr. Part No.M48T35Y-70PC1
kr 412,03
Each
Units
Battery Backup, Calendar, Chip Deselect, Switch Over, Write Protection DW:DM:M:Y HH:MM:SS 32768B Parallel Through Hole PCDIP 28 39.88 x 18.34 x 8.89mm 39.88mm 18.34mm 8.89mm 5.5 V
RS Stock No. 166-1602
Mfr. Part No.PCF8563TS/4,118
BrandNXP
kr 17,005
Each (On a Reel of 2500)
Units
Alarm, Battery Backup, Calendar, Watchdog Timer DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount TSSOP 8 3.1 x 3.1 x 0.95mm 3.1mm 3.1mm 0.95mm 5.5 V
RS Stock No. 168-8017
Mfr. Part No.M48T12-70PC1
kr 281,484
Each (In a Tube of 14)
Units
Timekeeper SRAM D:M:Y HH:MM:SS 16kbit - Through Hole PCDIP 24 34.8 x 18.34 x 8.89mm 34.8mm 18.34mm 8.89mm 5.5 V
RS Stock No. 511-103
Mfr. Part No.PCF8563TS/4,118
BrandNXP
kr 26,634
Each (In a Pack of 5)
Units
Alarm, Battery Backup, Calendar, Watchdog Timer DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount TSSOP 8 3.1 x 3.1 x 0.95mm 3.1mm 3.1mm 0.95mm 5.5 V
RS Stock No. 729-3237
Mfr. Part No.RV-4162-C7-TA-020
kr 60,55
Each
Units
Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SMD 8 3.2 x 1.5 x 0.8mm 3.2mm 1.5mm 0.8mm 4.4 V
RS Stock No. 828-9977
Mfr. Part No.M48T12-70PC1
kr 305,49
Each
Units
Timekeeper SRAM D:M:Y HH:MM:SS 16kbit - Through Hole PCDIP 24 34.8 x 18.34 x 8.89mm 34.8mm 18.34mm 8.89mm 5.5 V
RS Stock No. 865-2208
Mfr. Part No.PCF8563T/5,518
BrandNXP
kr 14,111
Each (In a Pack of 10)
Units
Calendar, Clock YY:MM:DD:dd HH:MM:SS - Serial-2 Wire, Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.45mm 5mm 4mm 1.45mm 5.5 V
RS Stock No. 774-7403
Mfr. Part No.MCP7940M-I/P
BrandMicrochip
kr 8,154
Each (In a Bag of 10)
Units
Alarm, Calendar DW:DM:M:Y HH:MM:SS 64B Serial-I2C Through Hole PDIP 8 10.16 x 7.11 x 4.95mm 10.16mm 7.11mm 4.95mm 5.5 V
RS Stock No. 171-1643
Mfr. Part No.RV-8564-C2-TA-010
kr 55,89
Each (On a Tape of 100)
Units
Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SON 10 5 x 3.2 x 1.2mm 5mm 3.2mm 1.2mm 5.5 V
RS Stock No. 823-7954
Mfr. Part No.MCP79511-I/MS
BrandMicrochip
kr 14,916
Each (In a Pack of 5)
Units
Calendar D:W:M:Y, LY HH, HS, MM, SS 64B Serial-SPI Surface Mount MSOP 10 3 x 3 x 0.95mm 3mm 3mm 0.95mm 3.6 V
RS Stock No. 729-3230
Mfr. Part No.RV-8564-C2-TA-010
kr 65,34
Each
Units
Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SON 10 5 x 3.2 x 1.2mm 5mm 3.2mm 1.2mm 5.5 V
RS Stock No. 124-2362
Mfr. Part No.PCF8563T/5,518
BrandNXP
kr 9,25
Each (On a Reel of 2500)
Units
Calendar, Clock YY:MM:DD:dd HH:MM:SS - Serial-2 Wire, Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.45mm 5mm 4mm 1.45mm 5.5 V
RS Stock No. 729-3234
Mfr. Part No.RV-8564-C3-TA-020
kr 50,33
Each
Units
Alarm, Interrupt, Timer - - - Serial-I2C Surface Mount SON 10 - 3.7mm 3.7mm 2.5mm 5.5 V
RS Stock No. 171-1646
Mfr. Part No.RV-4162-C7-TA-020
kr 44,762
Each (On a Tape of 100)
Units
Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SMD 8 3.2 x 1.5 x 0.8mm 3.2mm 1.5mm 0.8mm 4.4 V
RS Stock No. 920-9001
Mfr. Part No.M48T35Y-70PC1
kr 380,862
Each (In a Tube of 12)
Units
Battery Backup, Calendar, Chip Deselect, Switch Over, Write Protection DW:DM:M:Y HH:MM:SS 32768B Parallel Through Hole PCDIP 28 39.88 x 18.34 x 8.89mm 39.88mm 18.34mm 8.89mm 5.5 V
RS Stock No. 165-2097
Mfr. Part No.MCP79511-I/MS
BrandMicrochip
kr 14,487
Each (In a Tube of 100)
Units
Calendar D:W:M:Y, LY HH, HS, MM, SS 64B Serial-SPI Surface Mount MSOP 10 3 x 3 x 0.95mm 3mm 3mm 0.95mm 3.6 V
RS Stock No. 146-0203
Mfr. Part No.MCP7940M-I/P
BrandMicrochip
kr 7,942
Each (In a Tube of 60)
Units
Alarm, Calendar DW:DM:M:Y HH:MM:SS 64B Serial-I2C Through Hole PDIP 8 10.16 x 7.11 x 4.95mm 10.16mm 7.11mm 4.95mm 5.5 V
RS Stock No. 171-1645
Mfr. Part No.RV-8564-C3-TA-020
kr 33,351
Each (On a Tape of 100)
Units
Alarm, Interrupt, Timer - - - Serial-I2C Surface Mount SON 10 - 3.7mm 3.7mm 2.5mm 5.5 V
RS Stock No. 192-1541
Mfr. Part No.DS1338Z-18+
kr 70,23
Each (In a Pack of 2)
Units
Calendar YY:MM:DD HH:MM:SS 56B Serial-2 Wire, Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V
RS Stock No. 145-9302
Mfr. Part No.M41T0M6F
kr 17,423
Each (On a Reel of 2500)
Units
Real Time Clock DW:DM:M:Y HH:MM:SS 8B Serial-2 Wire, Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V