1°C Triple SMBus Sensor with Resistance Error Correction

Datasheet

SMSC EMC1033

11

Revision 1.1 (01-19-07)

DATASHEET

is a function of temperature. The higher the temperature measured, the greater the error introduced.

To provide maximum flexibility to the user, the EMC1033 provides a 6-bit ideality factor register for

each remote diode. The ideality factor of the remote diode is programmed in these registers to

eliminate errors across all temperatures. See section Section 4.18, "Ideality Factor Register," on

page 19 for details on programming these registers.

4.4

Temperature Measurement Results and Data

The 11-bit temperature measurement results are stored in temperature value registers. The EMC1033

has two temperature ranges and the default range is from 0 to 127

°C. This range uses binary number

format, and the most significant bit is not used. The extended range is from –64

°C to +191°C and is

binary offset by 64

°C. Table 4.1 shows the two temperature data formats with an LSB equivalent to

0.125

°C. The format is selected as described in Section 4.11, "Configuration Register," on page 16

Note 4.1

Data in Binary Format reads 0000 0000 000 for all temperatures

≤ 0.00°C

Note 4.2

Data in Offset Binary Format reads 0000 0000 000 for all temperatures

≤ -64

Note 4.3

Data in Binary Format reads 0111 1111 000 for all temperatures

≥ +127°C

Note 4.4

Data in Offset Binary Format reads 1111 1111 000 for all temperatures

≥ +191

The 11-bit temperature data is stored with the 8 most significant bits stored in the High Byte register

and the 3 least significant bits in the Low Byte register. The Low Byte register contains the three least

significant bits as outlined in Table 4.2. These bits are stored in the upper three bits of the register,

and the five LSB positions of this register always read zero. In Table 4.2, the upper case “B” shows

the bit position of a 16-bit word created by concatenating the High Byte and Low Byte, and the lower

case “b” shows the bit position in the 11-bit temperature data. The resolution of the internal temperature

is 0.5

Table 4.1 Temperature Data Format

ACTUAL TEMP.

(

°C)

DEFAULT RANGE

BINARY

EXTENDED RANGE

OFFSET BINARY

-63

0000 0000 000 Note 4.1

0000 0001 000 Note 4.2

-0.125

0000 0000 000 Note 4.1

0011 1111 111

0

0000 0000 000 Note 4.1

0100 0000 000

+0.125

0000 0000 001

0100 0000 001

+0.250

0000 0000 010

0100 0000 010

+1

0000 0001 000

0100 0001 000

+127

0111 1111 000 Note 4.3

1011 1110 000

+128

0111 1111 000 Note 4.3

1011 1111 000

+190

0111 1111 000 Note 4.3

1111 1110 000

+191

0111 1111 000 Note 4.3

1111 1111 000 Note 4.4

Table 4.2 Bit Position of Two Byte Values

HIGH BYTE

LOW BYTE

B15

B14

B13

B12

B11

B10

B9

B8

B7

B6

B5

B4

B3

B2

B1

B0

b10

b9

b8

b7

b6

b5

b4

b3

b2

b1

b0

0

0

0

0

0