LM96163CISD/NOPB National Semiconductor, LM96163CISD/NOPB Datasheet - Page 37

• Manufacturer Part Number: LM96163CISD/NOPB
• Description: IC TEMP SENSOR DGTL REMOTE 10LLP
• Manufacturer: National Semiconductor
• Series: PowerWise®, TruTherm®r

Specifications of LM96163CISD/NOPB

• Function: Fan Control, Temp Monitor
• Topology: ADC (Sigma Delta), Comparator, Register Bank, Tach
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 85°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-LLP
• Temperature Sensor Function: Temp Sensor
• Interface Type: Serial (2-Wire)
• Resolution: 10+SignBit
• Package Type: LLP EP
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM96163CISDTR

3.4.1 Diode Non-Ideality Factor Effect on Accuracy
When a transistor is connected as a diode, the following re-
lationship holds for variables V
where:
•
•
•
•
•
•
•
In the active region, the -1 term is negligible and may be elim-
inated, yielding the following equation
In
was used in the fabrication of the particular diode. By forcing
two currents with a very controlled ratio(I
ing the resulting voltage difference, it is possible to eliminate
Equation
q = 1.6×10
T = Absolute Temperature in Kelvin
k = 1.38×10
η is the non-ideality factor of the process the diode is
manufactured on,
I
I
V
S
f
BE
= Forward Current through the base-emitter junction
= Saturation Current and is process dependent,
= Base-Emitter Voltage drop
2, η and I
−19
−23
Coulombs (the electron charge),
joules/K (Boltzmann's constant),
S
are dependant upon the process that
BE
, T and I
F2
F
:
/ I
FIGURE 8. Thermal Diode Current Paths
F1
) and measur-
(1)
(2)
37
the I
the relationship:
Solving
Equation 4
as the MMBT3904 is used. When this “diode” equation is ap-
plied to an integrated diode such as a processor transistor
with its collector tied to GND as shown in
a wide non-ideality spread. This wide non-ideality spread is
not due to true process variation but due to the fact that
Equation 4
TruTherm BJT beta compensation technology uses the tran-
sistor equation,
sentation of the topology of the thermal diode found in an
FPGA or processor.
TruTherm should only be enabled when measuring the tem-
perature of a transistor integrated as shown in the processor
of
Figure
S
term. Solving for the forward voltage difference yields
Equation 3
8, because
holds true when a diode connected transistor such
is an approximation.
Equation
for temperature yields:
Equation 5
30041043
5, which is a more accurate repre-
only applies to this topology.
Figure 8
www.national.com
it will yield
(3)
(4)
(5)