Real Time Clock – Mouser South Africa

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Real Time Clocks for Thermostats

Real Time Clocks (RTCs) are IC devices that keep track of time. A typical RTC can provide the time of day as well as the date via a serial bus such as I2C or SPI

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Image	Part #	Mfr.	Description	Datasheet	Availability	Pricing (USD) Filter the results in the table by unit price based on your quantity.	Qty.	Interface Type	Date Format	Time Format	Package/Case	Battery Backup Switching	Supply Voltage - Min	Supply Voltage - Max	Minimum Operating Temperature	Maximum Operating Temperature	Series	Mounting Style	Packaging
Real Time Clock I C Serial Real-Time Clock DS1339U-3+ Analog Devices / Maxim Integrated 1: $3.87 1,309In Stock	Mfr. Part No. DS1339U-3+ Mouser Part No 700-DS1339U-3	Analog Devices / Maxim Integrated	Real Time Clock I C Serial Real-Time Clock Learn More about Analog Devices / Maxim Integrated maxim hvac solutions	Datasheet	1,309In Stock	$3.87 $3.79 $3.77	Min.: 1 Mult.: 1 Max.: 1,047	Serial 2-Wire, I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	uSOP-8	Backup Switching	2.7 V	3.3 V	- 40 C	+ 85 C	DS1339U	SMD/SMT	Tube
Real Time Clock I2C GP RTCC 64B SRAM MCP7940N-I/MS Microchip Technology 1: $0.90 2,005In Stock	Mfr. Part No. MCP7940N-I/MS Mouser Part No 579-MCP7940N-I/MS	Microchip Technology	Real Time Clock I2C GP RTCC 64B SRAM Learn More about Microchip Technology microchip mcp7940n calendar	Datasheet	2,005In Stock	$0.90 $0.832	Min.: 1 Mult.: 1	Serial 2-Wire, I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	MSOP-8	Backup Switching	1.8 V	5.5 V	- 40 C	+ 85 C		SMD/SMT	Tube
Real Time Clock I2C GP RTCC 64B SRAM MCP7940N-I/ST Microchip Technology 1: $0.90 90In Stock 500Expected 2026/10/27	Mfr. Part No. MCP7940N-I/ST Mouser Part No 579-MCP7940N-I/ST	Microchip Technology	Real Time Clock I2C GP RTCC 64B SRAM Learn More about Microchip Technology microchip mcp7940n calendar	Datasheet	90In Stock 500Expected 2026/10/27	$0.90 $0.832	Min.: 1 Mult.: 1	Serial 2-Wire, I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	TSSOP-8	Backup Switching	1.8 V	5.5 V	- 40 C	+ 85 C		SMD/SMT	Tube
Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM ID MCP79410-I/MS Microchip Technology 1: $1.08 247In Stock 1,400Expected 2026/11/02	Mfr. Part No. MCP79410-I/MS Mouser Part No 579-MCP79410-I/MS	Microchip Technology	Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM ID Learn More about Microchip Technology microchip mcp794xx calendars	Datasheet	247In Stock 1,400Expected 2026/11/02	$1.08 $1.01 $1.00	Min.: 1 Mult.: 1	I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	MSOP-8	Backup Switching	1.8 V	5.5 V	- 40 C	+ 85 C		SMD/SMT	Tube
Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM ID MCP79410-I/ST Microchip Technology 1: $1.08 767In Stock	Mfr. Part No. MCP79410-I/ST Mouser Part No 579-MCP79410-I/ST	Microchip Technology	Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM ID Learn More about Microchip Technology microchip mcp794xx calendars	Datasheet	767In Stock	$1.08 $1.01 $1.00	Min.: 1 Mult.: 1	I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	TSSOP-8	Backup Switching	1.8 V	5.5 V	- 40 C	+ 85 C		SMD/SMT	Tube
Real Time Clock I C RTC with 56-Byte NV RAM DS1338U-33+ Analog Devices / Maxim Integrated 1: $6.23 410In Stock	Mfr. Part No. DS1338U-33+ Mouser Part No 700-DS1338U-33	Analog Devices / Maxim Integrated	Real Time Clock I C RTC with 56-Byte NV RAM	Datasheet	410In Stock	$6.23 $5.09 $4.33 $4.27 $4.06	Min.: 1 Mult.: 1 Max.: 328	I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	uSOP-8	Backup Switching	3 V	5.5 V	- 40 C	+ 85 C	DS1338U	SMD/SMT	Tube
Real Time Clock I C Serial Real-Time Clock DS1339U-33+ Analog Devices / Maxim Integrated 1: $7.04 818In Stock	Mfr. Part No. DS1339U-33+ Mouser Part No 700-DS1339U-33	Analog Devices / Maxim Integrated	Real Time Clock I C Serial Real-Time Clock Learn More about Analog Devices / Maxim Integrated maxim hvac solutions	Datasheet	818In Stock	$7.04 $5.40 $4.58 $4.54 View $4.31 $4.18	Min.: 1 Mult.: 1 Max.: 654	Serial 2-Wire, I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	uSOP-8	Backup Switching	2.97 V	5.5 V	- 40 C	+ 85 C	DS1339U	SMD/SMT	Tube
Real Time Clock 128 NVRAM Serial RTC 3.0 to 3.6 Vcc M41ST87WSS6F STMicroelectronics 1: $7.77 23In Stock 1,350On Order	Mfr. Part No. M41ST87WSS6F Mouser Part No 511-M41ST87WSS6F	STMicroelectronics	Real Time Clock 128 NVRAM Serial RTC 3.0 to 3.6 Vcc	Datasheet	23In Stock 1,350On Order	Cut Tape $7.77 $6.00 $5.55 $5.07 Reel $4.35 View $4.76 $4.14 MouseReel Available	Min.: 1 Mult.: 1 : 1,350	Serial 2-Wire, I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	SSOP-20	Backup Switching	2.7 V	3.6 V	- 40 C	+ 85 C	M41ST87W	SMD/SMT	Reel, Cut Tape, MouseReel
Real Time Clock RTC IC with 400 kHz I2C interface in TSSOP8 package. PCF8563TS/5,118 NXP Semiconductors 1: $1.90 394In Stock 15,000On Order	Mfr. Part No. PCF8563TS/5,118 Mouser Part No 771-PCF8563TS/5118	NXP Semiconductors	Real Time Clock RTC IC with 400 kHz I2C interface in TSSOP8 package.	Datasheet	394In Stock 15,000On Order On Order Ship Dates Mfr. No: PCF8563TS/5,118 Stock: 394 Can Dispatch Immediately On Order: 7,500 Expected 2026/10/23 7,500 Expected 2026/10/28 Factory Lead Time: 27 Weeks	Cut Tape $1.90 $1.40 $1.28 $1.14 View Reel $0.939 $1.07 $1.04 $1.03 $0.939 MouseReel Available	Min.: 1 Mult.: 1 : 2,500	I2C	YY-MM-DD-dd	HH:MM:SS (24 hr)	TSSOP-8	No Backup Switching	1 V	5.5 V	- 40 C	+ 85 C	PCF8563	SMD/SMT	Reel, Cut Tape, MouseReel
Real Time Clock Parallel RTC A 595-B Q4802LYPWR A 595-BQ A 595-BQ4802LYPWR BQ4802LYPW Texas Instruments 1: $10.09 40In Stock End of Life	Mfr. Part No. BQ4802LYPW Mouser Part No 595-BQ4802LYPW End of Life	Texas Instruments	Real Time Clock Parallel RTC A 595-B Q4802LYPWR A 595-BQ A 595-BQ4802LYPWR	Datasheet	40In Stock	$10.09 $8.15 $6.92 $6.27 View $6.22 $6.11 $6.00 Quote	Min.: 1 Mult.: 1	Parallel	YY-MM-DD-dd	HH:MM:SS (24 hr)	TSSOP-28	Backup Switching	2.7 V	3.6 V	0 C	+ 70 C	BQ4802LY	SMD/SMT	Tube
Real Time Clock I C Serial Real-Time Clock DS1337U+ Analog Devices / Maxim Integrated 1: $5.02 324In Stock	Mfr. Part No. DS1337U+ Mouser Part No 700-DS1337U	Analog Devices / Maxim Integrated	Real Time Clock I C Serial Real-Time Clock Learn More about Analog Devices / Maxim Integrated maxim ds1337 rtc	Datasheet	324In Stock	$5.02 $3.79 $3.47 $3.13 $2.97	Min.: 1 Mult.: 1 Max.: 259	I2C	YY-MM-DD-dd	HH:MM:SS:hh (12 hr, 24 hr)	uSOP-8	No Backup Switching	1.8 V	5.5 V	- 40 C	+ 85 C	DS1337U	SMD/SMT	Tube
Real Time Clock I C RTC with Trickle Charger DS1340U-33+ Analog Devices / Maxim Integrated 1: $6.64 119In Stock	Mfr. Part No. DS1340U-33+ Mouser Part No 700-DS1340U-33	Analog Devices / Maxim Integrated	Real Time Clock I C RTC with Trickle Charger Learn More about Analog Devices / Maxim Integrated maximds1343	Datasheet	119In Stock	$6.64 $5.09 $4.66	Min.: 1 Mult.: 1 Max.: 95	I2C	YY-MM-DD-dd	HH:MM:SS (24 hr)	uSOP-8	Backup Switching	2.97 V	5.5 V	- 40 C	+ 85 C	DS1340U	SMD/SMT	Tube

Real Time Clocks for Thermostats

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