TCN75-3.3MPA TELCOM [TelCom Semiconductor, Inc], TCN75-3.3MPA Datasheet - Page 5

• Manufacturer Part Number: TCN75-3.3MPA
• Description: 2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR
• Manufacturer: TELCOM [TelCom Semiconductor, Inc]

2-WIRE SERIAL TEMPERATURE
SENSOR AND THERMAL MONITOR
Address Byte
next transmit the address byte to the TCN75. The four most
significant bits of the Address Byte (A6, A5, A4, A3) are fixed
to 1001(B). The states of A2, A1 and A0 in the serial bit
stream must match the states of the A2, A1 and A0 address
inputs for the TCN75 to respond with an Acknowledge
(indicating the TCN75 is on the bus and ready to accept
data). The eighth bit in the Address Byte is a Read-Write Bit.
This bit is a 1 for a read operation or 0 for a write operation.
Acknowledge (ACK)
between the host and the TCN75. The host releases SDA
after transmitting eight bits then generates a ninth clock
cycle to allow the TCN75 to pull the SDA line LOW to
acknowledge that it successfully received the previous eight
bits of data or address.
Data Byte
must next transmit the data byte to be written or clock out the
data to be read. (See the appropriate timing diagrams.) ACK
will be generated after a successful write of a data byte into
the TCN75.
Stop Condition (STOP)
tion (a LOW to HIGH transition of SDA while SCL is HIGH).
The Stop Condition must be communicated by the transmit-
ter to the TCN75.
Power Supply
To minimize temperature measurement error, the
TCN75VO_-3 is factory calibrated at a supply voltage of
3.3V 5V and the TCN75CO_-5 is factory calibrated at a
supply voltage of 5V 5%. Either device is fully operational
TCN75-04 6/16/97
(Set as Desired)
I
2
C Interface
Address
Immediately following the Start Condition, the host must
Acknowledge (ACK) provides a positive handshake
After a successful ACK of the address byte, the host
Communications must be terminated by a stop condi-
SDA
SCL
A
A
A
0
1
2
Figure 1. Typical Application
7
6
5
1
2
TCN75
+V
8
4
DD
(3V to 5.5V)
C
Bypass
3
INT/CMPTR
0.1 F Recommended
Unless Device is Mounted
Close to CPU
TO PROCESSOR
5
over the power supply voltage range of 2.7V to 5.5V, but
with a lower measurement accuracy. Figure 2 shows the
worst case temperature measurement error for the
TCN75CO_-3 operated at a power supply voltage of 5V
10%. Figure 3 shows the worst case temperature measure-
ment error for the TCN75CO_-3 operated at a power supply
voltage of 3.3V 10%.
Figure 3. TCN75CO_-5 Measurement Error at V
Figure 2. TCN75CO_-3 Measurement Error at V
5
4
3
2
1
5
4
3
2
1
20
20
35
35
TCN75 Case Temeprature ( C)
TCN75 Case Temeprature ( C)
PRELIMINARY INFORMATION
50
50
65
65
80
80
95
95
DD
DD
= 3.3V
110
= 5V
110
TCN75
10%
10%
125
125