Datasheet

 2010 Microchip Technology Inc. DS21909D-page 9
MCP9800/1/2/3
3.0 PIN DESCRIPTION
The descriptions of the pins are listed in Tab l e 3-1.
TABLE 3-1: PIN FUNCTION TABLE
3.1 Serial Data Pin (SDA)
The SDA is a bidirectional input/output pin, used to
serially transmit data to and from the host controller.
This pin requires a pull-up resistor to output data.
3.2 Serial Clock Pin (SCLK)
The SCLK is a clock input pin. All communication and
timing is relative to the signal on this pin. The clock is
generated by the host controller on the bus.
3.3 Power Supply Input (V
DD
)
The V
DD
pin is the power pin. The operating voltage, as
specified in the DC electrical specification table, is
applied on this pin.
3.4 Ground (GND)
The GND pin is the system ground pin.
3.5 ALERT Output
The MCP9800/1/2/3’s ALERT pin is an open-drain
output pin. The device outputs an alert signal when the
ambient temperature goes beyond the
user-programmed temperature limit.
3.6 Address Pins (A2, A1, A0)
These pins are device or slave address input pins and
are available only with the MCP9801/03. The device
addresses for the MCP9800/02 are factory-set.
The address pins are the Least Significant bits (LSb) of
the device address bits. The Most Significant bits
(MSb) (A6, A5, A4, A3) are factory-set to <1001>. This
is illustrated in Tab le 3 - 2 .
MCP9800
MCP9802
SOT-23-5
MCP9801
MCP9803
MSOP, SOIC
Symbol Function
5 1 SDA Bidirectional Serial Data
4 2 SCLK Serial Clock Input
3 3 ALERT Temperature Alert Output
2 4 GND Ground
— 5 A2 Address Select Pin (bit 2)
— 6 A1 Address Select Pin (bit 1)
— 7 A0 Address Select Pin (bit 0)
18V
DD
Power Supply Input
TABLE 3-2: SLAVE ADDRESS
Device A6 A5 A4 A3 A2 A1 A0
MCP9800/02A0 1001000
MCP9800/02A1 1001001
MCP9800/02A2 1001010
MCP9800/02A3 1001011
MCP9800/02A4 1001100
MCP9800/02A5 1001101
MCP9800/02A6 1001110
MCP9800/02A7 1001111
MCP9801/03 1001XXX
Note: User-selectable address is shown by X.