Microchip EMC1428 Handleiding

Microchip Niet gecategoriseerd EMC1428

Lees hieronder de 📖 handleiding in het Nederlandse voor Microchip EMC1428 (6 pagina's) in de categorie Niet gecategoriseerd. Deze handleiding was nuttig voor 22 personen en werd door 2 gebruikers gemiddeld met 4.5 sterren beoordeeld

Download PDF
Pagina 1/6
2005-2014 Microchip Technology Inc. DS00001852A-page 1
AN13.19
INTRODUCTION
This application note describes the Resistance Error
Correction feature available on many Microchip
temperature sensor devices.
OVERVIEW
The information presented will show system designers
that the Resistance Error Correction (REC) feature
removes the need to compensate for series resistance
in the thermal diode connection. Figure 1 shows a
typical system and the remote diode-connected
transistor could be a central processing unit (CPU)
thermal diode or a discrete transistor located where the
temperature must be measured.
FIGURE 1: Block Diagram of Typical Temperature Sensing System.
Author: Wayne Little
Microchip Technology Inc.
System Controller
with SMBus
Interface
SMBus
Interface SMBus
Remote
Sensor
DP
DN
Remote
Diode-Connected
Transistor
Resistance Error Correction
AN13.19
DS00001852A-page 2 2005-2014 Microchip Technology Inc.
POSITIVE TEMPERATURE OFFSET
RESULTING FROM SERIES
RESISTANCE
Review of Temperature Sensing Method
A typical temperature sensor forces two fixed currents
(IF1 and IF2) into the thermal diode to measure
temperature, as shown in Figure 2 below. The forward
bias voltage (VF) of the diode is measured as each of
the two fixed currents is sourced into the diode. In
Figure 2, the value of VF measured at the DP/DN pins
inside the chip is equivalent to the value of V
BE at the
remote diode-connected transistor.
FIGURE 2: Two Current Sources.
The difference between the two values of V
F
(VF2 – VF1 = VBE) is used to determine the
temperature, as shown in Equation 1.
EQUATION 1:
I
F2
I
F1
Voltage to
Temperature
Conversion
V
F
V
BE
DP
DN
Remote
Diode-Connected
Transistor
Where:
k = Boltzmann’s constant
T = Absolute temperature in Kelvin
q = Electron charge
η= Diode ideality factor
VF2 V
F1
–
kT
q
--------- IF2
IF1
-------
 
 
ln=
2005-2014 Microchip Technology Inc. DS00001852A-page 3
AN13.19
Figure 3 shows that the relationship of V
F2 – VF1 to
temperature is linear. In this plot, the Ideality Factor (ƞ) is
assumed to be 1.000 and the IF2/IF1 ratio is 17. The value
of VF2 – VF1 will change to 244 µV when the temperature
changes from 25°C to 26°C or from 100°C to 101°C.
FIGURE 3: VF2 – VF1 vs. Temperature.
Positive Temperature Offset Resulting
from Series Resistance
In the real world, series resistance will be present in the
path from the DP pin to the actual junction of the diode
and back to the DN pin of the temperature sensor.
Sources of series resistance include package leads,
Printed Circuit Board (PCB) traces, other forms of
interconnect and the physical structure of the remote
diode itself. In Figure 4, all these sources of series
resistance are combined and shown as RS.
FIGURE 4: Block Diagram of Temperature Monitoring Circuit.
When series resistance is present in the system, the V
F
value measured at the DP/DN pins inside the chip is no
longer equivalent to the value of VBE. The VF value with
series resistance is shown in Equation 2.
EQUATION 2:
This RS term will always induce a positive temperature
measurement offset error. The reported temperature
will be higher than the actual amount by the value
obtained using Equation 3.
EQUATION 3:
This means that a system could be operating at an
acceptable temperature but the sensor would report
that it is beyond critical temperature because of the
series resistance.
60
65
70
75
80
85
90
95
273 293 313 333 353 373
V
F2
– V
F1
(mV)
Temperature (K)
(VF2 – VF1) = 0.2441 X Temperature
I
F2
I
F1
Voltage to
Temperature
Conversion
V
F
V
BE
DP
DN
Remote
Diode-Connected
Transistor
RS
VFVBE IFRS
 +=
TOFFSET
q
k
-------- IF2 IF1
– RS
IF2
IF1
-------
 
 
ln
--------------------------------=

Product specificaties

Merk: Microchip
Categorie: Niet gecategoriseerd
Model: EMC1428

Heb je hulp nodig?

Als je hulp nodig hebt met Microchip EMC1428 stel dan hieronder een vraag en andere gebruikers zullen je antwoorden


Handleiding Niet gecategoriseerd Microchip

Microchip

Microchip EVB-USB2504 Handleiding

17 November 2024
Microchip

Microchip AT97SC3204 Handleiding

17 November 2024
Microchip

Microchip ATECC608B Handleiding

16 Juli 2024
Microchip

Microchip HV860 Handleiding

16 Juli 2024
Microchip

Microchip EVB-LAN9255 Handleiding

16 Juli 2024
Microchip

Microchip LX4580 Handleiding

16 Juli 2024
Microchip

Microchip LX7720 Handleiding

16 Juli 2024
Microchip

Microchip AT32UC3C0128C Handleiding

10 April 2024
Microchip

Microchip AT32UC3C1512C Handleiding

10 April 2024
Microchip

Microchip AT32UC3A3256 Handleiding

10 April 2024

Handleiding Niet gecategoriseerd

Nieuwste handleidingen voor Niet gecategoriseerd

Taga Harmony

Taga Harmony TOS-600 v.2 Handleiding

26 November 2024
Trace Elliot

Trace Elliot Pro 2x12 Cabinet Handleiding

26 November 2024
Kramer

Kramer K-Bar Camera Bracket Handleiding

26 November 2024
Kramer

Kramer RK-19 Handleiding

26 November 2024
Kramer

Kramer OSP-MM1 Handleiding

26 November 2024
Kramer

Kramer ASPEN-1616UX Handleiding

26 November 2024
Korg

Korg Pitchstrap Handleiding

26 November 2024
NeoMounts

NeoMounts WL70-450BL11 Handleiding

26 November 2024
Kramer

Kramer CLS-AOCH/60 Handleiding

26 November 2024
Klauke

Klauke EKM 6022ISM Handleiding

26 November 2024