Microchip MCP7940M-I/SN, Real Time Clock (RTC), 64B RAM Serial-I2C, 8-Pin SOIC

  • RS stock no. 912-6943
  • Mfr. Part No. MCP7940M-I/SN
  • Manufacturer Microchip
Technical data sheets
Legislation and Compliance
COO (Country of Origin): TH
Product Details

MCP7940M I²C Real-Time Clock/Calendars

The Microchip MCP7940M is Real-Time Clock Calendar (RTCC) that supports I²C communications. The MCP7940M includes a digital trimming circuit for accuracy which can compensate for crystal tolerance and temperature.

The MCP7940M features a multi-functional output that can be configured as an alarm output, to output a selectable frequency square wave or as a general purpose output.


2-Wire Serial Interface, I²C™ Compatible: I²C clock rate up to 400 kHz
On-Chip Digital Trimming/Calibration: ±1 ppm resolution, ±129 ppm range
Tracks Hours, Minutes, Seconds, Day of Week, Day, Month and Year
Leap Year Compensated to 2399
12/24 Hour Modes
Oscillator for 32.768 kHz Crystals: Optimised for 6-9 pF crystals
Dual Programmable Alarms
Versatile Output Pin
Wide Operating Voltage Range: 1.8V to 5.5V
Low Typical Timekeeping Current: 1.2μA at 3.3V

Real Time Clock Peripherals - Microchip

Attribute Value
Functions Calendar, NV SRAM
Date Format DW:DM:M:Y
Time Format HH:MM:SS
User RAM 64B
Bus Type Serial-I2C
Mounting Type Surface Mount
Package Type SOIC
Pin Count 8
Dimensions 4.9 x 3.9 x 1.25mm
Length 4.9mm
Width 3.9mm
Height 1.25mm
Maximum Operating Supply Voltage 5.5 V
Minimum Operating Temperature -40 °C
Maximum Operating Temperature +85 °C
Minimum Operating Supply Voltage 1.8 V
500 Available in 4-6 working days for collection or delivery to major cities, unless heavy, bulky, hazardous or lithium metal (T&C’s Apply)
Price (Excl VAT) Each (In a Tube of 100)
R 8.208
(exc. VAT)
R 9.439
(inc. VAT)
Per unit
Per Tube*
100 +
R 8.208
R 820.80
*price indicative
Not Available for premium delivery