MCP79400 Datasheet, PDF (6/38 Pages) Microchip Technology – I2C™ Real-Time Clock/Calendar with SRAM, Unique ID and Battery Switchover

MCP7940X
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
FIGURE 2-1:
DEVICE PINOUTS
SOIC/DFN/MSOP/TSSOP
X1 1
X2 2
VBAT 3
Vss 4
8 Vcc
7 MFP
6 SCL
5 SDA
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 VCC (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.
TABLE 2-1: PIN DESCRIPTIONS
Pin Name
Pin Function
Vss
SDA
SCL
X1
X2
VBAT
MFP
Vcc
Ground
Bidirectional Serial Data
Serial Clock
Xtal Input, External Oscillator Input
Xtal Output
Battery Backup Input (3V Typ)
Multi Function Pin
+1.8V to +5.5V Power Supply
DS25009A-page 6
 2011 Microchip Technology Inc.