TMP411CD datasheet(16/32 Pages) TI

16 / 32 page

TMP411

SBOS383C − DECEMBER 2006 − REVISED MAY 2008

www.ti.com

SERIAL INTERFACE

The TMP411 operates only as a slave device on either the

Two-Wire bus or the SMBus. Connections to either bus are

made via the open-drain I/O lines, SDA and SCL. The SDA

and SCL pins feature integrated spike suppression filters

and Schmitt triggers to minimize the effects of input spikes

and bus noise. The TMP411 supports the transmission

protocol for fast (1kHz to 400kHz) and high-speed (1kHz

to 3.4MHz) modes. All data bytes are transmitted MSB

first.

SERIAL BUS ADDRESS

To communicate with the TMP411, the master must first

address slave devices via a slave address byte. The slave

address byte consists of seven address bits, and a

direction bit indicating the intent of executing a read or

write operation.

The address of the TMP411A is 4Ch (1001100b). The

address of the TMP411B is 4Dh (1001101b). The address

of the TMP411C is 4Eh (1001110b).

READ/WRITE OPERATIONS

Accessing a particular register on the TMP411 is

accomplished by writing the appropriate value to the

Pointer Register. The value for the Pointer Register is the

first byte transferred after the slave address byte with the

R/W bit low. Every write operation to the TMP411 requires

a value for the Pointer Register (see Figure 14).

When reading from the TMP411, the last value stored in

the Pointer Register by a write operation is used to

determine which register is read by a read operation. To

change the register pointer for a read operation, a new

value must be written to the Pointer Register. This

transaction is accomplished by issuing a slave address

byte with the R/W bit low, followed by the Pointer Register

byte. No additional data are required. The master can then

generate a START condition and send the slave address

byte with the R/W bit high to initiate the read command.

See Figure 15 for details of this sequence. If repeated

reads from the same register are desired, it is not

necessary to continually send the Pointer Register bytes,

because the TMP411 retains the Pointer Register value

until it is changed by the next write operation. Note that

Table 11. THERM Hysteresis Register Format

THERM HYSTERESIS REGISTER (Read = 21h, Write = 21h, POR = 0Ah)

BIT #

BIT NAME

TH11

TH10

TH9

TH8

TH7

TH6

TH5

TH4

POR VALUE

TMP411CD Datasheet(PDF) 16 Page - Texas Instruments

TMP411CD Datasheet(HTML) 16 Page - Texas Instruments

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

Datasheet Download

Link URL