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 212 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 Maximum Operating Temperature
RS Stock No. 732-7315
Mfr. Part No.DS1302ZN+
SGD6.31
Each
units
Calendar, NV RAM, Trickle Charger DW:DM:M:Y HH:MM:SS 31B Serial Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V +85 °C
RS Stock No. 761-9755
Mfr. Part No.DS1302ZN+T&R
SGD6.53
Each
units
Battery Backup, Calendar, NV RAM YY:MM:DD HH:MM:SS 31B Serial-3 Wire Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V +85 °C
RS Stock No. 732-7327
Mfr. Part No.DS1305EN+
SGD9.07
Each
units
Battery Backup, Calendar, NV RAM DW:DM:M:Y HH:MM:SS 96B Serial-SPI Surface Mount TSSOP 20 6.6 x 4.5 x 0.95mm 6.6mm 4.5mm 0.95mm 5.5 V +85 °C
RS Stock No. 192-1456
Mfr. Part No.DS12C887A+
SGD15.57
Each
units
Alarm, Calendar YY:MM:DD HH:MM:SS 128B Multiplexed Through Hole EDIP 24 38.1 x 18.29 x 10.67mm 38.1mm 18.29mm 10.67mm 5.5 V +85 °C
RS Stock No. 190-5149
Mfr. Part No.DS1670E+
SGD13.97
Each
units
Real Time Clock, SRAM DM:M:DW:Y SS:MM:HH - Multiplexed Surface Mount TSSOP 20 6.6 x 4.5 x 0.95mm 6.6mm 4.5mm 0.95mm 3.63 V +70 °C
RS Stock No. 923-7778
Mfr. Part No.DS1747-70+
SGD56.588
Each (In a Tube of 10)
units
Calendar YY:MM:DD HH:MM:SS 512 x 8bit Parallel Through Hole EDIP 32 44.2 x 18.8 x 10.92mm 44.2mm 18.8mm 10.92mm 0.8 V, 5.3 V +70 °C
RS Stock No. 189-8388
Mfr. Part No.DS2417P+
SGD3.864
Each (In a Pack of 5)
units
Battery Backup, Calendar, ROM Binary Binary - Serial Surface Mount TSOC 6 4 x 3.89 x 1.5mm 4mm 3.89mm 1.5mm 5.5 V +85 °C
RS Stock No. 923-5781
Mfr. Part No.DS1306E+
SGD7.11
Each (In a Tube of 74)
units
Battery Backup, Calendar, NV RAM DW:DM:M:Y HH:MM:SS 96B Serial-SPI Surface Mount TSSOP 20 6.6 x 4.5 x 0.95mm 6.6mm 4.5mm 0.95mm 5.5 V +70 °C
RS Stock No. 732-7573
Mfr. Part No.DS3231S#
SGD13.71
Each
units
Battery Backup, Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SOIC 16 10.5 x 7.6 x 2.35mm 10.5mm 7.6mm 2.35mm 5.5 V +70 °C
RS Stock No. 923-7462
Mfr. Part No.DS1305EN+T&R
SGD4.123
Each (On a Reel of 2500)
units
Battery Backup, Calendar, NV RAM YY:MM:DD HH:MM:SS 96B Serial-3 Wire Surface Mount TSSOP 20 6.6 x 4.5 x 0.95mm 6.6mm 4.5mm 0.95mm 5.5 V +85 °C
RS Stock No. 192-1246
Mfr. Part No.DS1744W-120+
SGD36.36
Each (In a Tube of 12)
units
Calendar YY:MM:DD HH:MM:SS 32 x 8B Parallel Through Hole EDIP 28 39.37 x 18.8 x 10.67mm 39.37mm 18.8mm 10.67mm 0.6 V, 3.6 V +70 °C
RS Stock No. 189-7194
Mfr. Part No.DS12887+
SGD14.689
Each (In a Tube of 14)
units
Alarm, Battery Backup, Calendar, Power Fail Binary, DW:DM:M:Y Binary, HH:MM:SS 114B Multiplexed Through Hole EDIP 24 34.04 x 18.8 x 9.4mm 34.04mm 18.8mm 9.4mm 5.5 V +70 °C
RS Stock No. 189-8635
Mfr. Part No.DS1337S+
SGD4.488
Each (In a Pack of 5)
units
Calendar DW:DM:M:Y HH:MM:SS - Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V +85 °C
RS Stock No. 190-5143
Mfr. Part No.DS1340Z-33+T&R
SGD5.104
Each (In a Pack of 5)
units
Real Time Clock, Trickle Charger D:D:M:Y SS:MM:HH - Serial-I2C Surface Mount SO 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V +85 °C
RS Stock No. 192-1230
Mfr. Part No.DS12C887A+
SGD13.831
Each (In a Tube of 14)
units
Alarm, Calendar YY:MM:DD HH:MM:SS 128B Multiplexed Through Hole EDIP 24 38.1 x 18.29 x 10.67mm 38.1mm 18.29mm 10.67mm 5.5 V +85 °C
RS Stock No. 192-1449
Mfr. Part No.DS1685E-3+
SGD9.29
Each (In a Pack of 2)
units
Alarm, Calendar YY:MM:DD HH:MM:SS 128B Multiplexed Surface Mount TSSOP 24 7.9 x 4.5 x 0.95mm 7.9mm 4.5mm 0.95mm 5 V +70 °C
RS Stock No. 190-4731
Mfr. Part No.DS1338U-33+T&R
SGD2.858
Each (On a Reel of 3000)
units
NV SRAM, Real Time Clock DM:M:DW:Y SS:MM:HH - Serial-I2C Surface Mount μSOP 8 3.1 x 0.65 x 0.95mm 3.1mm 0.65mm 0.95mm 5.5 V +85 °C
RS Stock No. 189-8548
Mfr. Part No.DS1307Z+T&R
SGD4.774
Each (In a Pack of 5)
units
Battery Backup, Calendar, NV RAM YY:MM:DD HH:MM:SS 56B Serial-I2C Surface Mount SOIC 8 5 x 4 x 1.5mm 5mm 4mm 1.5mm 5.5 V +70 °C
RS Stock No. 189-8563
Mfr. Part No.DS12887+
SGD16.25
Each
units
Alarm, Battery Backup, Calendar, Power Fail Binary, DW:DM:M:Y Binary, HH:MM:SS 114B Multiplexed Through Hole EDIP 24 34.04 x 18.8 x 9.4mm 34.04mm 18.8mm 9.4mm 5.5 V +70 °C
RS Stock No. 189-8345
Mfr. Part No.DS1394U-33+
SGD5.71
Each (In a Pack of 5)
units
Trickle Charger DD:M:Y SS:MM:HH - Serial-SPI Surface Mount μMAX 10 3.05 x 3.05 x 0.95mm 3.05mm 3.05mm 0.95mm 5.5 V +85 °C