MCP79521

The MCP79521 SPI RTCC is highly integrated with memory and advanced features normally found in higher priced devices. By starting with a basic real-time clock, digital trimming was added for higher accuracy, a battery switchover for backup power, a timestamp to log power failures and three types of memory, which includes SRAM, EEPROM and a unique ID in a locked section of EEPROM. This ID is preprogrammed with a 48-bit MAC Address, but it can also be ordered blank for the end user to program.

Features
  • Low Power Operation VCC Min = 1.8V Icc < 5 µA (Typical Standby Current)
  • VCC Min = 1.8V
  • Icc < 5 µA (Typical Standby Current)
  • Low Backup Power VBAT Min = 1.3V Ibat < 700nA Typical Timekeeping & SRAM Retention Current
  • VBAT Min = 1.3V
  • Ibat < 700nA Typical Timekeeping & SRAM Retention Current
  • Automatic Battery Switchover with Timestamp VCC to VBAT (VCC Lost) VBAT to VCC (VCC Restored)
  • VCC to VBAT (VCC Lost)
  • VBAT to VCC (VCC Restored)
  • Dual configurable alarms with a 0.01 sec count on one alarm IRQ (VCC or VBAT)
  • IRQ (VCC or VBAT)
  • Clock Out frequencies: 32.768, 8.192 & 4.096 KHz and 1 Hz
  • Digital Trimming Range from -255 to + 255 ppm in 1 ppm steps Adjusts up to 22 seconds/day
  • Adjusts up to 22 seconds/day
  • EEPROM has 8 Bytes/Page with Block Sector write protection Protect: None, 1/4, 1/2 or all of array
  • Protect: None, 1/4, 1/2 or all of array
  • Factory standard MAC address programming or custom ID available
Parameter
Parameter Name Value Value
Max Communications Speed 10 MHz 10 MHz
Pin Count 10 10
Minimum Clock Count (seconds) 0.01 sec 0.01 sec
Battery-backed SRAM (Bytes) 64 64
EEPROM (Kbits) 2 2
Unique ID (bits) 128 128
Unique ID Programming EUI-48 EUI-48
Temperature Range (C) -40 to +85 -40 to +85
Documents
MCP795XX 3V SPI RTCC Data SheetData Sheets04/17/2012905KB
MCP795XX Family Silicon ErrataErrata12/15/201565KB
AN1365 - Recommended Usage of Microchip Serial RTCC DevicesAppNote03/28/2013267KB
AN1412 - How to Calculate UNIX Time Using a PIC18 Microcontroller and the MCP795W20 SPI RTCCAppNote01/31/2012318KB
AN1413 - Temperature Compensation of a Tuning Fork Crystal Based on MCP79410AppNote11/07/2011479KB
AN1519 - Recommended Crystals for Microchip Stand-Alone Real-Time Clock/Calendar DevicesAppNote09/16/2013397KB
AN1950 - Configuring and Using the MCP795WXX SPI RTCC for Basic Timekeeping, Based on a PIC18AppNote06/08/2015146KB
AN2027 - Backup Power Sources for Microchip's RTCCs and SRAMsAppNote12/01/2015161KB
AN2140 - Configuring and Using the Alarm Module of the MCP795WXX Real-Time Clock/CalendarsAppNote05/11/2016154KB
TB3116 - Questions and Answers Concerning MCP79XXX Serial RTCCsAppNote08/11/201475KB
Ordering Information
Part NumberLeadsPackage TypeTemp RangePacking1+26+100+1000+5000+
MCP79521-I/MS10MSOP-40C to +85CTUBE1.281.181.121.061.02
MCP79521T-I/MN10TDFN-40C to +85CT/R1.281.181.121.061.02
MCP79521T-I/MS10MSOP-40C to +85CT/R1.281.181.121.061.02
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RoHS Information
PartNumberDeviceWeightShippingWeightLeadCountPackageTypePackageWidthSolderCompositionJEDECIndicatorRoHSChinaEFUP
MCP79521-I/MS0.0232000.06000010MSOP3x3mmMatte Tine3
MCP79521T-I/MS0.0232000.20000010MSOP3x3mmMatte Tine3
MCP79521T-I/MN0.0210000.22878810TDFN3x3x0.8mmMatte Tine3
MCP795XX 3V SPI RTCC Data Sheet MCP79522
MCP795XX Family Silicon Errata MCP79522
AN1365 MCP795W22
AN1412 MCP795W22
AN1413 MCP795W22
AN1413 Source Code MCP795W22
AN1519 MCP795W22
AN1950 MCP795W21
AN1950 Source Code MCP795W21
AN2027 MCP795W22
AN2140 MCP795W22
AN2140 Source Code MCP795W22
TB3116 MCP795W22