EMC1043 Standard Microsystems Corp., EMC1043 Datasheet - Page 13

• Manufacturer Part Number: EMC1043
• Description: 1 Degree C Triple Temperature Sensor With Beta Compensation And Hotter Of Two Zones
• Manufacturer: Standard Microsystems Corp.

1°C Triple Temperature Sensor with Beta Compensation and Hotter of Two Zones
Datasheet
SMSC EMC1043
3.4
Substrate
PNP
Δ
V
BE
In general, thermal diode temperature measurements are based on the change in forward bias voltage
of a diode when operated at two different currents. This ΔV
temperature as shown in the following equation:
Figure 3.2
the remote temperature diode, DN, is internally biased with a forward diode voltage referenced to
ground.
The EMC1043-1, EMC1043-2, EMC1043-3 and EMC1043-4 are designed to work with the PNP
substrate transistor in a CPU. The External Diode 2 channel in the EMC1043-5 has beta compensation
disabled by default.
The external diodes in all versions of the EMC1043 are compatible with a broad range of thermal
diodes that may be connected as shown in
using diode-connected transistors as the external diodes).
Temperature Monitors
=
V
I
LOW
Resistance
Correction
BE
_
Error
HIGH
shows a block diagram of the temperature measurement circuit. The negative terminal for
Figure 3.2 Block Diagram of Temperature Monitoring Circuit
−
V
BE
_
LOW
=
I
HIGH
η
kT
q
DN
DP
ln
DATASHEET
⎛
⎜ ⎜
⎝
I
I
HIGH
LOW
Aliasing
Filter
Anti-
13
Figure 3.3
⎞
⎟ ⎟
⎠
where:
k = Boltzmann’s constant
T = absolute temperature in Kelvin
q = electron charge
η
(see
= diode ideality factor
Section 4.8
BE
is then proportional to absolute
for programming details when
ADC
Revision 1.44 (04-14-08)
ΔΣ
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