MCP79412T-I/MS Microchip Technology, MCP79412T-I/MS Datasheet - Page 15

• Manufacturer Part Number: MCP79412T-I/MS
• Description: Real Time Clock I2C GP RTCC 1Kb EE 64B SRAM EUI-64
• Manufacturer: Microchip Technology
• Series: -r
• Type: Clock/Calendarr

Specifications of MCP79412T-I/MS

• Function: Clock/Calendar
• Rtc Memory Size: 64 Byte
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Rtc Bus Interface: I2C
• Supply Current: 1 uA
• Features: Alarm, Leap Year, NVSRAM, Square Wave Output, Unique ID
• Memory Size: 64B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C
• Voltage - Supply: 1.8 V ~ 5.5 V
• Voltage - Supply, Battery: 1.3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

In the case where the MSB of the Calibration register
is set to ‘1’, the MFP output waveforms that appear
when bits RS1 and RS0 are set to ‘01’ or ‘10’ are not
as responsive to the setting of the Calibration register.
For example, when outputting the 4.096 kHz
waveform (RS1, RS0 set to ‘01’), the output waveform
is generated using only eight input clock cycles.
Consequently, attempting to subtract more than eight
input clock cycles from this output does not have a
meaningful effect on the resulting waveform. Any
effect on the output will appear as a modification in
both the frequency and duty cycle of the waveform
appearing on the MFP output pin.
B. RS2 BIT SET TO ‘1’
With the RS2 bit set to ‘1’, the following internal timing
signal is output on the MFP pin:
The frequency listed in the table presumes an input
clock source of exactly 32.768 kHz. In terms of the
equivalent number of input clock cycles, the table
becomes:
Unlike
calibration setting is continuously applied and affects
every cycle of the output waveform. This results in the
modulation of the frequency of the output waveform
based upon the setting of the Calibration register.
Using this setting, the calibration function can be
expressed as:
Since the calibration is done every cycle, the frequency
of the output MFP waveform is constant.
 2010-2011 Microchip Technology Inc.
where:
CALREG
RS2
RS2
1
1
T
T
T
output
output
input
the
RS1
RS1
x
x
=
=
=
=
method
(2 * (256 +/- (2 * CALREG))) T
clock period of MFP output signal
clock period of input signal
decimal value of the Calibration
register setting, and the sign is
determined by the MSB of the
Calibration register.
RS0
RS0
x
x
previously
Output Signal
Output Signal
64.0 Hz
described,
512
input
the
4.2.4
Pin 7 is a multi-function pin and supports the following
functions:
• The value of the OUT bit determines the logic
• Alarm Outputs – Available in V
• FOUT mode – driven from a FOSC divider – Not
The internal control logic for the MFP is connected to
the switched internal supply bus, this allows operation
in V
operates in V
4.2.5
The MCP7941X features an internal switch that will
power the clock and the SRAM. In the event that the
V
V
series resistor is recommended between the external
battery and the V
internal switch circuit.
The V
switch operates the device from the V
is typically 1.5V (V
When V
operate the RTCC and SRAM using the V
The following conditions apply:
TABLE 4-2:
If the V
be connected to GND. For more information on V
conditions see the RTCC Best Practices Application
Note, AN1365.
V
V
V
CC
BAT
level of the I/O. This is only available when oper-
ating from V
available in V
CC
CC
CC
BAT
supply is not available, the voltage applied to the
< V
> V
> V
pin serves as the backup supply. A low-value
BAT
BAT
mode. The Alarm Output is the only mode that
DD
Condition
TRIP
TRIP
TRIP
Supply
trip point is the point at which the internal
feature is not being used, the V
falls below 1.5V the system will continue to
MFP
V
, V
, V
, V
BAT
BAT
CC
BAT
CC
CC
CC
.
mode, other modes are suspended.
BAT
< V
< V
> V
mode
TRIP
BAT
BAT
BAT
pin to limit the current to the
MCP7941X
specification D12) typical.
Read/Write
Access
BAT
Yes
Yes
No
DS22266C-page 15
mode
BAT
BAT
BAT
supply and
Powered
pin must
V
V
V
supply.
By
BAT
CC
CC
BAT