MCP79400_13 Datasheet, PDF (1/42 Pages) Microchip Technology – I2C Real-Time Clock/Calendar with SRAM, Unique IDand Battery Switchover

MCP79400/MCP79401/MCP79402
I²C™ Real-Time Clock/Calendar with SRAM, Unique ID
and Battery Switchover
Device Selection Table
Part Number
SRAM
(Bytes)
Unique ID
MCP79400
64
MCP79401
64
MCP79402
64
Blank
EUI-48^™
EUI-64^™
Features:
• Real-Time Clock/Calendar (RTCC), Battery
Backed:
- Hours, Minutes, Seconds, Day of Week, Day,
Month and Year
- Dual alarm with single output
• On-Chip Digital Trimming/Calibration:
- Range -127 to +127 ppm
- Resolution 1 ppm
• Programmable Open-Drain Output Control:
- CLKOUT with 4 selectable frequencies
- Alarm output
• 64 Bytes SRAM, Battery Backed
• 64-Bit Unique ID:
- User or factory programmable
- Protected EEPROM
- EUI-48^™ or EUI-64^™ MAC address
- Custom ID programming
• Automatic VCC Switchover to VBAT Backup
Supply
• Power-Fail Time-Stamp for Battery Switchover
• Low-Power CMOS Technology:
- Dynamic Current: 400 A max read
- Dynamic Current: 400 A max SRAM
- Battery Backup Current: <700nA @ 1.8V
• 100 kHz and 400 kHz Compatibility
• ESD Protection >4,000V
• 1 Million Erase/Write Cycles for Unique ID
• Packages include 8-Lead SOIC, TSSOP, 2x3
TDFN, MSOP
• Pb-Free and RoHS Compliant
• Temperature Ranges:
- Industrial (I): -40°C to +85°C
Description:
The MCP7940X series of low-power Real-Time Clocks
(RTC) uses digital timing compensation for an accurate
clock/calendar, a programmable output control for
versatility, a power sense circuit that automatically
switches to the backup supply, and nonvolatile memory
for data storage. Using a low-cost 32.768 kHz crystal,
it tracks time using several internal registers. For
communication, the MCP7940X uses the I²C™ bus.
The clock/calendar automatically adjusts for months
with fewer than 31 days, including corrections for
leap years. The clock operates in either the 24-hour
or 12-hour format with an AM/PM indicator and
settable alarm(s) to the second, minute, hour, day of
the week, date or month. Using the programmable
CLKOUT, frequencies of 32.768, 8.192 and 4.096
kHz and 1 Hz can be generated from the external
crystal.
Along with the battery-backed SRAM memory, a 64-bit
protected EEPROM space is available for a unique ID
or MAC address to be programmed at the factory or by
the end user.
The device is fully accessible through the serial
interface while VCC is between 1.8V and 5.5V, but can
operate down to 1.3V for timekeeping and SRAM
retention only.
The RTC series of devices are available in the standard
8-lead SOIC, TSSOP, MSOP and 2x3 TDFN packages.
Package Types
MSOP
X1 1
8 VCC
X2 2
7
V_BAT 3
6
VSS 4
5
SOIC, TSSOP
X1 1
8
X2 2
7
V_BAT
3
6
VSS 4
5
MFP
SCL
X1 1
SDA
X2 2
VBAT ₃
VSS 4
VCC
TDFN
8 VCC
7 MFP
6 SCL
5 SDA
MFP
SCL
SDA
 2011 Microchip Technology Inc.
DS25009C-page 1