MCP9800 datasheet(11/42 Pages) MICROCHIP

Part #	MCP9800

Description	2-Wire High-Accuracy Temperature Sensor

Download	42 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

Logo

11 / 42 page

 2010 Microchip Technology Inc.

DS21909C-page 11

MCP9800/1/2/3

4.0

SERIAL COMMUNICATION

4.1

2-Wire SMBus/Standard Mode

I2C™ Protocol-Compatible

Interface

The MCP9800/1/2/3 serial clock input (SCL) and the

bidirectional serial data line (SDA) form a 2-wire

bidirectional SMBus/Standard mode I2C compatible

communication port (refer to the Digital Input/Output

Pin Characteristics Table

and Serial Interface

Timing Specifications Table

).

The following bus protocol has been defined:

TABLE 4-1:

MCP9800 SERIAL BUS

PROTOCOL DESCRIPTIONS

4.1.1

DATA TRANSFER

Data transfers are initiated by a Start condition (Start),

followed by a 7-bit device address and a read/write bit.

An Acknowledge (ACK) from the slave confirms the

reception of each byte. Each access must be

terminated by a Stop condition (Stop).

Repeated communication is initiated after tB-FREE.

This device does not support sequential register read/

write. Each register needs to be addressed using the

Register Pointer.

This device supports the Receive Protocol. The

register can be specified using the pointer for the initial

read. Each repeated read or receive begins with a Start

condition and address byte. The MCP9800/1/2/3

retains the previously selected register. Therefore, it

outputs data from the previously-specified register

(repeated pointer specification is not necessary).

4.1.2

MASTER/SLAVE

The bus is controlled by a master device (typically a

microcontroller) that controls the bus access and

generates the Start and Stop conditions. The

MCP9800/1/2/3 is a slave device and does not control

other devices in the bus. Both master and slave

devices can operate as either transmitter or receiver.

However, the master device determines which mode is

activated.

4.1.3

START/STOP CONDITION

A high-to-low transition of the SDA line (while SCL is

high) is the Start condition. All data transfers must be

preceded by a Start condition from the master. If a Start

condition is generated during data transfer, the

MCP9800/1/2/3 resets and accepts the new Start

condition.

A low-to-high transition of the SDA line (while SCL is

high) signifies a Stop condition. If a Stop condition is

introduced during data transmission, the MCP9800/1/

2/3 releases the bus. All data transfers are ended by a

Stop condition from the master.

4.1.4

ADDRESS BYTE

Following the Start condition, the host must transmit an

8-bit address byte to the MCP9800/1/2/3. The address

for

the

MCP9800

Temperature

Sensor

is

‘1001,A2,A1,A0’ in binary, where the A2, A1 and A0

bits are set externally by connecting the corresponding

pins to VDD ‘1’ or GND ‘0’. The 7-bit address

transmitted in the serial bit stream must match the

selected address for the MCP9800/1/2/3 to respond

with an ACK. Bit 8 in the address byte is a read/write

bit. Setting this bit to ‘1’ commands a read operation,

while ‘0’ commands a write operation (see Figure 4-1).

Term

Description

Master

The device that controls the serial bus,

typically a microcontroller.

Slave

The device addressed by the master,

such as the MCP9800/1/2/3.

Transmitter Device sending data to the bus.

Receiver

Device receiving data from the bus.

Start

A unique signal from master to initiate

serial interface with a slave.

Stop

A unique signal from the master to

terminate serial interface from a slave.

Read/Write A read or write to the MCP9800/1/2/3

registers.

ACK

A receiver Acknowledges (ACK) the

reception of each byte by polling the

bus.

NAK

A receiver Not-Acknowledges (NAK) or

releases the bus to show End-of-Data

(EOD).

Busy

Communication is not possible

because the bus is in use.

Not Busy

The bus is in the Idle state, both SDA

and SCL remain high.

Data Valid

SDA must remain stable before SCL

becomes high in order for a data bit to

be considered valid. During normal

data transfers, SDA only changes state

while SCL is low.

Similar Part No. - MCP9800

Manufacturer	Part #	Datasheet	Description
Microchip Technology	MCP9800	329Kb / 30P	2-Wire High-Accuracy Temperature Sensor 2010
	MCP9800	2Mb / 44P	Analog & Interface Product Selector Guide 11/29/11
	MCP9800	2Mb / 44P	Analog and Interface Product Selector Guide 11/29/11
	MCP9800	503Kb / 30P	2-Wire High-Accuracy Temperature Sensor 09/27/04
	MCP9800A0T-M/OTG	329Kb / 30P	2-Wire High-Accuracy Temperature Sensor 2010

More results

Similar Description - MCP9800

Manufacturer	Part #	Datasheet	Description
Microchip Technology	MCP9803-M	503Kb / 30P	2-Wire High-Accuracy Temperature Sensor 09/27/04
Microchip Technology	MCP9800	329Kb / 30P	2-Wire High-Accuracy Temperature Sensor 2010
Seiko Instruments Inc	S-5852ABCAC-A8T1U4	1Mb / 15P	HIGH-ACCURACY DIGITAL TEMPERATURE SENSOR
Linear Dimensions Semic...	DC2126A	724Kb / 10P	High-Accuracy Wireless Temperature Sensor
Greystone Energy System...	PS-HATSPC	204Kb / 2P	HIGH ACCURACY ROOM TEMPERATURE SENSOR
	PS-HATSRC	200Kb / 2P	HIGH ACCURACY ROOM TEMPERATURE SENSOR
	PS-HATSBB	157Kb / 2P	HIGH ACCURACY DUCT TEMPERATURE SENSOR
	PS-HATSOS	256Kb / 2P	HIGH ACCURACY OUTSIDE TEMPERATURE SENSOR
Seiko Instruments Inc	S5852A	805Kb / 15P	HIGH-ACCURACY DIGITAL TEMPERATURE SENSOR
Greystone Energy System...	PS-HATSGL	137Kb / 1P	HIGH ACCURACY GLASS TEMPERATURE SENSOR

More results

MCP9800 Datasheet(PDF) 11 Page - Microchip Technology

MCP9800 Datasheet(HTML) 11 Page - Microchip Technology

Similar Part No. - MCP9800

Similar Description - MCP9800

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Datasheet Download

Link URL