Datasheet

 2010-2015 Microchip Technology Inc. DS20002266G-page 1
MCP79410/MCP79411/MCP79412
Device Selection Table
Timekeeping Features:
• Real-Time Clock/Calendar (RTCC):
- Hours, minutes, seconds, day of week, day,
month, year
- Leap year compensated to 2399
- 12/24-hour modes
• Oscillator for 32.768 kHz Crystals:
- Optimized for 6-9 pF crystals
• On-Chip Digital Trimming/Calibration:
- ±1 ppm resolution
- ±129 ppm range
• Dual Programmable Alarms
• Versatile Output Pin:
- Clock output with selectable frequency
- Alarm output
- General purpose output
• Power-Fail Time-Stamp:
- Time logged on switchover to and from Battery
mode
Low-Power Features:
• Wide Voltage Range:
- Operating voltage range of 1.8V to 5.5V
- Backup voltage range of 1.3V to 5.5V
• Low Typical Timekeeping Current:
- Operating from V
CC: 1.2 µA at 3.3V
- Operating from V
BAT: 925 nA at 3.0V
• Automatic Switchover to Battery Backup
User Memory:
• 64-byte Battery-Backed SRAM
• 1 Kbit EEPROM Memory:
- Software write-protect
- Page write up to 8 bytes
- Endurance: 1M Erase/Write cycles
• 64-bit Protected EEPROM Area:
- Robust write unlock sequence
-EUI-48
™
MAC address (MCP79411)
-EUI-64
™
MAC address (MCP79412)
Operating Ranges:
• 2-Wire Serial Interface, I
2
C™ Compatible:
-I
2
C clock rate up to 400 kHz
• Temperature Range:
- Industrial (I): -40°C to +85°C
Packages:
• 8-Lead SOIC, MSOP, TSSOP and 2x3 TDFN
General Description:
The MCP7941X Real-Time Clock/Calendar (RTCC)
tracks time using internal counters for hours, minutes,
seconds, days, months, years, and day of week. Alarms
can be configured on all counters up to and including
months. For usage and configuration, the MCP7941X
supports I
2
C communications up to 400 kHz.
The open-drain, multi-functional output can be
configured to assert on an alarm match, to output a
selectable frequency square wave or as a general
purpose output.
The MCP7941X is designed to operate using a
32.768 kHz tuning fork crystal with external crystal load
capacitors. On-chip digital trimming can be used to
adjust for frequency variance caused by crystal
tolerance and temperature.
SRAM and timekeeping circuitry are powered from the
backup supply when main power is lost, allowing the
device to maintain accurate time and the SRAM
contents. The times when the device switches over to
the back-up supply and when primary power returns are
both logged by the power-fail time-stamp.
The MCP7941X features 1 Kbit of internal nonvolatile
EEPROM with software write-protectable regions. There
is an additional 64 bits of protected nonvolatile memory
which is only writable after an unlock sequence, making
it ideal for storing a unique ID or other critical informa-
tion. The MCP79411 and MCP79412 are
pre-programmed with EUI-48 and EUI-64 addresses,
respectively. Custom programming is also available.
Package Types
Part Number Protected EEPROM
MCP79410 Unprogrammed
MCP79411 EUI-48
™
MCP79412 EUI-64
™
SOIC, TSSOP, MSOP
X1
X2
V
BAT
VSS
1
2
3
4
8
7
6
5
V
CC
MFP
SCL
SDA
TDFN
X1
X2
V
SS
MFP
SDA
V
CC8
7
5
1
2
4
VBAT 3SCL6
Battery-Backed I
2
C™ Real-Time Clock/Calendar with
SRAM, EEPROM and Protected EEPROM