1°C Triple SMBus Temperature Sensor

Datasheet

SMSC EMCT03

11

Revision 2.3 (04-19-05)

DATASHEET

Table 3.7 and Table 3.8 show that temperature data is stored in 2’s complement in both Legacy and

Extended Temperature Data Format. Both extended and legacy temperature formats are updated

simultaneously after every conversion cycle. Code 8000h is reserved for diode fault signaling which

occurs when open or short conditions are present between the external DP and DN pins.

3.7

Status Register

The Status register is a read only register and returns the operational status of the part. It indicates an

external diode fault conditions through bit 0 and 1. When either D1 or D2 is set, a faulty diode

connection is detected for external diode 1 or external diode 2 respectively. Also, when diode faults

are detected, temperature readings for the faulty external diode will return 8000h. The EMCT03 detects

both open and short conditions for the DP1/2 and DN1/2 pins. Bit 7 of the status register will be set

when the internal ADC is busy converting data.

3.8

Configuration Register

Bits 0 through bit 2 of the configuration register set the ADC conversion rate of the part:

+65

1

0000 0001 0000 0000

0100

+191

127

0111 1111 0000 0000

7F00

= +191.875

127.875

0111 1111 1110 0000

7FE0

Table 3.9 Status Register

REGISTER

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

DEF

Status

Busy

-

-

-

-

-

D2

D1

00h

Table 3.10 Configuration Register

REGISTER

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

DEF

Configuration

-

nRun/Stop

-

-

-

CR2

CR1

CR0

47h

Table 3.11 Configuration Register, Conversion Rate

CR2, CR1, CR0

CONVERSION RATE

000

Reserved

001

Reserved

010

Reserved

011

1 Conversions per second

100

2 Conversions per second

101

4 Conversions per second

110

8 Conversions per second

111

16 Conversions per second

Table 3.8 Extended Temperature Data Format (continued)

ACTUAL TEMP.

(

°C)

-64

°C OFFSET

(

°C)

2’S COMPLEMENT

OF -64

°C OFFSET

HEX