MCP7940NT-I-MNY Datasheet, PDF (1/42 Pages) Microchip Technology – Low-Cost I2C Real-Time Clock/Calendar with SRAM and Battery Switchover

MCP7940N
Low-Cost I²C™ Real-Time Clock/Calendar
with SRAM and Battery Switchover
Device Selection Table
Part Number
SRAM
(Bytes)
MCP7940N
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
• Automatic VCC Switchover to VBAT Backup
Supply
• Power-Fail Time-Stamp for Battery Switchover
• Low-Power CMOS Technology:
- Dynamic Current: 400 A max read
- Battery Backup Current: <700nA @ 1.8V
• 100 kHz and 400 kHz Compatibility
• ESD Protection >4,000V
• Packages include 8-Lead SOIC, TSSOP, 2x3
TDFN, MSOP
• Pb-Free and RoHS Compliant
• Temperature Ranges:
- Industrial (I): -40°C to +85°C
- Extended (E): -40°C to +125°C
Description:
The MCP7940N 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. Using a low-cost 32.768
kHz crystal, it tracks time using several internal
registers. For communication, the MCP7940N 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.
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
 2011-2013 Microchip Technology Inc.
DS25010E-page 1