Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

IRF7401 Fiches technique(PDF) 9 Page - Analog Devices

No de pièce IRF7401
Description  Thermoelectric Cooler Controller
Download  24 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  AD [Analog Devices]
Site Internet  http://www.analog.com
Logo AD - Analog Devices

IRF7401 Fiches technique(HTML) 9 Page - Analog Devices

Back Button IRF7401 Datasheet HTML 5Page - Analog Devices IRF7401 Datasheet HTML 6Page - Analog Devices IRF7401 Datasheet HTML 7Page - Analog Devices IRF7401 Datasheet HTML 8Page - Analog Devices IRF7401 Datasheet HTML 9Page - Analog Devices IRF7401 Datasheet HTML 10Page - Analog Devices IRF7401 Datasheet HTML 11Page - Analog Devices IRF7401 Datasheet HTML 12Page - Analog Devices IRF7401 Datasheet HTML 13Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 9 / 24 page
background image
REV. C
ADN8830
–9–
Although the thermistor has a nonlinear relationship to tem-
perature, near optimal linearity over a specified temperature
range can be achieved with the proper value of RX. First, the
resistance of the thermistor must be known, where
RR
T
T
RT
T
RT
T
THERM
T
LOW
TMID
T
HIGH
==
==
==
1
2
3
@
@
@
(2)
TLOW and THIGH are the endpoints of the temperature range and
TMID is the average. These resistances can be found in most
thermistor data sheets. In some cases, only the coefficients
corresponding to the Steinhart-Hart equation are given. The
Steinhart-Hart equation is
1
11
3
T
ab n R
c
n R
=+
()+
()
[]
(3)
where T is the absolute temperature of the thermistor in Kelvin
(K =
°C + 273.15), and R is the resistance of the thermistor at
that temperature. Based on the coefficients a, b, and c, RTHERM
can be calculated for a given T, albeit somewhat tediously, by
solving the cubic roots of this equation
RTHERM =+
+


++


exp
––
χχ
ψ
χχ
ψ
24
27
24
27
2
3
1
2
1
3
2
3
1
2
1
3
(4)
where
X
a
T
c
=
1
and
ψ=
b
c
RX is then found as
R
RR
R R
RR
RR
R
X
TT
T
T
TT
TT
T
=
+
+
12
2
3
13
13
2
2
2
(5)
For the best accuracy as well as the widest selection range for
resistances, RX should be 0.1% tolerance. Naturally, the smaller
the temperature range required for control, the more linear
the voltage divider will be with respect to temperature. The
voltage at THERMIN is
V
VREF
R
RR
X
THERM
THERM
X
=
+
(6)
where VREF has a typical value of 2.47 V.
The ADN8830 control loop will adjust the temperature of the
TEC until VX equals the voltage at TEMPSET (Pin 4), which
we define as VSET. Target temperature can be set by
Vm T
T
V
SET
MID
XMID
=
()+
(7)
where T equals the target temperature, and
m
VV
TT
X HIGH
X LOW
HIGH
LOW
=
,,
(8)
VX for high, mid, and low are found by using Equation 6 and
substituting RT3, RT2, and RT1, respectively, for RTHERM. The
variable m is the change in VX with respect to temperature and
is expressed in V/
°C.
The setpoint voltage can be driven from a DAC or another
voltage source, as shown in Figure 4. The reference voltage
for the DAC should be connected to VREF (Pin 7) on the
ADN8830 to ensure best accuracy from device to device.
For a fixed target temperature, a voltage divider network can be
used as shown in Figure 5. R1 is set equal to RX, and R2 is
equal to the value of RTHERM at the target temperature.
3.3V
ADN8830
8
4
7
30
AD7390
6
8
5
3.3V
7
1–4
C
Figure 4. Using a DAC to Control the Temperature
Setpoint
3.3V
ADN8830
8
7
4
30
R2
R1
Figure 5. Using a Voltage Divider to Set a Fixed
Temperature Setpoint
Design Example 1
A laser module requires a constant temperature of 25
°C. From
the manufacturer’s data sheet, we find the thermistor in the laser
module has a value of 10 k
Ω at 25°C. Because the laser is not
required to operate at a range of temperatures, the value of RX
can be set to 10 k
Ω. TEMPSET can be set by a simple resistor
divider as shown in Figure 5, with R1 and R2 both equal to 10 k
Ω.
Design Example 2
A laser module requires a continuous temperature control from
5
°C to 45°C. The manufacturer’s data sheet shows the thermistor
has a value of 10 k
Ω at 25°C, 25.4 kΩ at 5°C, and 4.37 kΩ at
45
°C. Using Equation 5, R
X is calculated to be 7.68 k
Ω to yield
the most linear temperature-to-voltage conversion. A DAC
will be used to set the TEMPSET voltage.
DAC Resolution for TEMPSET
The temperature setpoint voltage to THERMIN can be set from
a DAC. The DAC must have a sufficient number of bits to achieve
adequate temperature resolution from the system. The voltage
range for THERMIN is found by multiplying the variable m
from Equation 8 by the temperature range.
THERMIN Voltage Range
m
T
T
MAX
MIN
()
(9)
From Design Example 2, 40
°C of the control temperature range
is achieved with a voltage range of only 1 V.


Numéro de pièce similaire - IRF7401

FabricantNo de pièceFiches techniqueDescription
logo
International Rectifier
IRF7401 IRF-IRF7401 Datasheet
118Kb / 9P
   Power MOSFET(Vdss=20V, Rds(on)=0.022ohm)
logo
Analog Devices
IRF7401 AD-IRF7401 Datasheet
279Kb / 22P
   Thermoelectric Cooler Controller
REV. D
logo
Guangdong Youtai Semico...
IRF7401 UMW-IRF7401 Datasheet
408Kb / 8P
   N-Channel MOSFET
logo
International Rectifier
IRF7401PBF IRF-IRF7401PBF Datasheet
197Kb / 9P
   HEXFET짰 Power MOSFET
IRF7401PBF IRF-IRF7401PBF Datasheet
202Kb / 9P
   ULTRA LOW ON RESISTANCE
More results

Description similaire - IRF7401

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
ADN8830 AD-ADN8830_15 Datasheet
279Kb / 22P
   Thermoelectric Cooler Controller
REV. D
ADN8830ACPZ AD-ADN8830ACPZ Datasheet
279Kb / 22P
   Thermoelectric Cooler Controller
REV. D
ADN8831ACPZ-R2 AD-ADN8831ACPZ-R2 Datasheet
408Kb / 20P
   Thermoelectric Cooler (TEC) Controller
REV. A
ADN8831 AD-ADN8831 Datasheet
505Kb / 11P
   Thermoelectric Cooler (TEC) Controller
Rev. PrC
ADN8831ACP AD-ADN8831ACP Datasheet
408Kb / 20P
   Thermoelectric Cooler (TEC) Controller
REV. A
ADN8831 AD-ADN8831_15 Datasheet
408Kb / 20P
   Thermoelectric Cooler (TEC) Controller
REV. A
logo
Linear Technology
LTC1923 LINER-LTC1923_15 Datasheet
452Kb / 28P
   High Efficiency Thermoelectric Cooler Controller
LTC1923 LINER-LTC1923 Datasheet
452Kb / 28P
   High Efficiency Thermoelectric Cooler Controller
logo
Microsemi Corporation
LX1810 MICROSEMI-LX1810 Datasheet
133Kb / 6P
   ThermoElectric Cooler Drive Controller IC
logo
List of Unclassifed Man...
RC6-4 ETC2-RC6-4 Datasheet
475Kb / 2P
   Thermoelectric Cooler
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com