MCP9804-E/MS Microchip Technology, MCP9804-E/MS Datasheet - Page 13

• Manufacturer Part Number: MCP9804-E/MS
• Description: IC TEMP SENSOR I2C 2.7V 8MSOP
• Manufacturer: Microchip Technology

Specifications of MCP9804-E/MS

• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Function: Temp Monitoring System (Sensor)
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: Internal
• Sensing Temperature: -40°C ~ 125°C
• Output Type: I²C™/SMBus™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Temperature Threshold: + 150 C
• Full Temp Accuracy: +/- 0.25 %
• Digital Output - Bus Interface: 2-Wire, I2C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 200 uA
• Ic Output Type: Digital
• Sensing Accuracy Range: ± 0.25°C
• Temperature Sensing Range: -40°C To +125°C
• Supply Voltage Range: 2.7V To 5.5V
• Sensor Case Style: MSOP
• No. Of Pins: 8
• Rohs Compliant: Yes
• Supply Voltage Min: 2.7V
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

4.0
4.1
The MCP9804 serial clock input (SCL) and the
bidirectional serial data line (SDA) form a 2-wire
bidirectional
communication port (refer to the Digital Input/Output
Pin
Interface Timing Specifications table).
The following bus protocol has been defined:
TABLE 4-1:
4.1.1
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 t
This device does not support sequential register read/
write. Each register needs to be addressed using the
Register Pointer.
© 2009 Microchip Technology Inc.
Master
Slave
Transmitter Device sending data to the bus.
Receiver
START
STOP
Read/Write A read or write to the MCP9804
ACK
NAK
Busy
Not Busy
Data Valid
Term
Characteristics
SERIAL COMMUNICATION
2-Wire Standard Mode I
Protocol-Compatible Interface
DATA TRANSFER
The device that controls the serial bus,
typically a microcontroller.
The device addressed by the master,
such as the MCP9804.
Device receiving data from the bus.
A unique signal from master to initiate
serial interface with a slave.
A unique signal from the master to
terminate serial interface from a slave.
registers.
A receiver Acknowledges (ACK) the
reception of each byte by polling the
bus.
A receiver Not-Acknowledges (NAK) or
releases the bus to show End-of-Data
(EOD).
Communication is not possible
because the bus is in use.
The bus is in the idle state, both SDA
and SCL remain high.
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.
Standard
MCP9804 SERIAL BUS
PROTOCOL DESCRIPTIONS
table
Description
mode
and
I
2
Sensor
C
2
C™
B-FREE
compatible
Serial
.
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 MCP9804 retains the
previously selected register. Therefore, it outputs data
from the previously-specified register (repeated pointer
specification is not necessary).
4.1.2
The bus is controlled by a master device (typically a
microcontroller) that controls the bus access and
generates the Start and Stop conditions. The MCP9804
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
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. A
low-to-high transition of the SDA line (while SCL is
high) signifies a Stop condition.
If a Start or Stop condition is introduced during data
transmission, the MCP9804 releases the bus. All data
transfers are ended by a Stop condition from the
master.
4.1.4
Following the Start condition, the host must transmit an
8-bit address byte to the MCP9804. The address for
the
‘0011,A2,A1,A0’ in binary, where the A2, A1 and A0
bits are set externally by connecting the corresponding
pins to V
transmitted in the serial bit stream must match the
selected address for the MCP9804 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:
SDA
SCL
See
Table 3-2: "MCP9804 Address Byte"
Start
MCP9804
DD
MASTER/SLAVE
START/STOP CONDITION
ADDRESS BYTE
0
1 2 3
‘1’ or GND ‘0’. The 7-bit address
Address
Code
0
1 1 A2 A1 A0
Device Addressing.
Address Byte
Temperature
4 5
Address
Slave
MCP9804
6
MCP9804 Response
7
R/W
DS22203B-page 13
Figure
8
9
A
C
K
Sensor
4-1).
is