Datasheet
MCP7940M
DS22292A-page 6 Preliminary 2012 Microchip Technology Inc.
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Tabl e 2- 1.
TABLE 2-1: PIN DESCRIPTIONS
FIGURE 2-1: DEVICE PINOUTS
2.1 Serial Data (SDA)
This is a bidirectional pin used to transfer addresses
and data into and out of the device. It is an open-drain
terminal, therefore, the SDA bus requires a pull-up
resistor to V
CC (typically 10 k for 100 kHz, 2 k for
400 kHz). For normal data transfer, SDA is allowed to
change only during SCL low. Changes during SCL high
are reserved for indicating the Start and Stop
conditions.
2.2 Serial Clock (SCL)
This input is used to synchronize the data transfer from
and to the device.
2.3 X1, X2
External Crystal Pins.
2.4 MFP
Open-drain pin used for alarm and clock-out.
Pin Name Pin Function
V
SS Ground
SDA Bidirectional Serial Data
SCL Serial Clock
X1 Xtal Input, External Oscillator Input
X2 Xtal Output
NC Not Connected
MFP Multi-Function Pin
V
CC +1.8V to +5.5V Power Supply
X1
X2
NC
V
SS
VCC
MFP
SCL
SDA
1
2
3
4
8
7
6
5
SOIC/DFN/MSOP/TSSOP