1°C Triple SMBus Temperature Sensor

Datasheet

SMSC EMCT03

15

Revision 2.3 (04-19-05)

DATASHEET

2. The lowest emitter and base resistance values will also be helpful as a matter of series input

resistance

4.1.2.2

Compensating for Ideality of the diode

The remote diode may have an ideality factor based on the manufacturing process. Inaccuracy in the

temperature measurement resulting from this ideality factor may be eliminated by calibrating the

remote diode with the temperature sensor. The EMCT03 is trimmed to an ideality factor of 1.008.

4.1.2.3

Circuit Connections

The more negative terminal for the remote temperature diode, DN, is internally biased with a forward

diode voltage. Terminal DN is not referenced to ground. Remote temperature diodes can be

constructed as shown in Figure 4.2 Remote Temperature Diode Examples on page 15.

Figure 4.2 Remote Temperature Diode Examples

Environmental Monitoring and Control (EMC) devices supplied by SMSC are designed to make

accurate temperature measurements. Careful design of the printed circuit board and proper selection

of the remote sensing diode will help to maintain the accuracy.

To DP

To DN

Local Ground

Typical Remote Parasitic

Substrate Transistor

e.g. CPU substrate PNP

To DP

To DN

To DP

To DN

Typical Remote

Discrete PNP Transistor

e.g 2N3906

Typical Remote

Discrete NPN Transistor

e.g. 2N3904