TMP141 datasheet(11/19 Pages) TI

11 / 19 page

TMP141

SBAS347 − MARCH 2005

www.ti.com

This is an 8-bit register with the following bits defined:

Bit 7, Bus Error (BER): This bit is set whenever there is

an error indication in the Acknowledge bit of either

received or transmitted data. A bus error is cleared when

the master reads the Device Status Register or sends

Device Reset.

Bits 6−5: Reserved. These bits read as ‘0’.

Bit 4, Overrun (ORUN): This flag is set when another

temperature conversion is completed before the previous

conversion has been read by the master. This error is

cleared by Device Reset, or by reading the temperature

result from the Temperature Readout register.

Bits 3−1: Reserved. These bits read as ‘0’.

Bit 0, Status Function 1 (SF1): This flag is set when a

temperature conversion is completed, and the data is

stored in the Readout register. It is reset either when the

master reads the temperature conversion, or when the

TMP141 is reset.

Bits 15−5: Reserved. These bits read as ‘0’.

Bit 4, Enable Function 1 (ENAB): This bit enables

temperature measurement; the default setting is disabled.

To begin temperature measurement, a ‘1’ must be written

to this bit. The enable sensor bit (EN_S) in the

Temperature Control register must also be set to enable

the sensor. (Bits cannot be written individually; a Write

operation affects the entire register.)

Bit 3: Reserved. This bit reads as ‘0’.

Bit 2, Low-Power Mode: When this bit is set, the

operation of all functions slow down in order to conserve

power. Default is ‘0’ for normal speed operation. (See

Table 4.)

Bit 1, Shutdown: When this bit is set, all functions are

disabled, placing the TMP141 in the lowest possible power

consumption mode. Default is ‘0’; this is normal operation.

To exit shutdown, write a ‘0’ to this location.

Bit 0, Reset: When this bit is set, the TMP141 performs a

Device Reset. During Reset, any operation is progress is

aborted, and all registers are set to their default values.

This bit self-clears when the Reset operation is completed.

It is not necessary to do a Device Reset after power-up.

Bits 1−0: These bits are the only location in the TMP141

that accepts a broadcast Write message.

Bits 15−9: Reserved. These bits read as ‘0’.

Bit 8: This bit is set, indicating that the internal temperature

sensing is the only option available.

Bit 7: This bit is ‘0’; it indicates that the TMP141 Tempera-

ture Readout register is 16 bits.

Bit 6: This bit is set to indicate that signed two’s

complement is the format of the temperature data.

Bits 5−3: These bits are 001b; they indicate that the

temperature data is 10 bits long.

Bits 2−0: These bits are 010b, and indicate that the

temperature data resolution is 0.25

°C.

The TMP141 outputs 10 bits of precision to a resolution of

0.25

°C. This 10-bit format covers a range from +127.75°C

to −128

°C. Negative numbers are in two’s complement.

Table 3 shows some examples of the Temperature Data

format.

Data is left-justified, meaning that the ten bits of data are

in the most significant bits of this register. The temperature

data is contained in Bits 15:6. Bits 5:0 always read as ‘0’.

Table 3. Data Format Example

TEMPERATURE

BINARY

HEX

+127.75

°C(1)

01 1111 1111

1FFh

+125.00

°C

01 1111 0100

1F4h

+100.0

°C

01 1001 0000

190h

+1.0

°C

00 0000 0100

004h

+0.25

°C

00 0000 0001

001h

°C

00 0000 0000

000h

−0.25

°C

11 1111 1111

3FFh

−1.0

°C

11 1111 1100

3FCh

−100

°C

10 0111 0000

270h

−128

°C(1)

10 0000 0000

200h

(1) Both −128°C and +127.75°C are beyond the specified operating

range of −40

°C to +125°C. This table only illustrates the format

of the data.

TMP141 Datasheet(PDF) 11 Page - Texas Instruments

TMP141 Datasheet(HTML) 11 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Datasheet Download

Link URL