U.S. patent application number 15/190254 was filed with the patent office on 2017-07-13 for methods and control systems of resistance adjustment of resistors.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Anthony I. Chou, Arvind Kumar, Sungjae Lee.
Application Number | 20170199532 15/190254 |
Document ID | / |
Family ID | 56411102 |
Filed Date | 2017-07-13 |
United States Patent
Application |
20170199532 |
Kind Code |
A1 |
Chou; Anthony I. ; et
al. |
July 13, 2017 |
METHODS AND CONTROL SYSTEMS OF RESISTANCE ADJUSTMENT OF
RESISTORS
Abstract
Embodiments include methods, computer systems and computer
program products for controlling resistance value of a resistor in
a circuit. Aspects include: retrieving, via a controller, a set of
parameters of the resistor from a non-volatile memory in the
circuit, detecting, via the controller, an operating temperature of
the resistor during circuit operation in field using a temperature
sensor, generating, by the controller, a temperature difference
between operating temperature detected and a target temperature at
which the resistor has a target resistance value, producing, by the
controller, a control signal responsive to the temperature
difference generated, and transmitting the control signal to a
temperature regulator placed adjacent to the resistor to adjust the
resistance value of the resistor. Resistance value of resistor
varies in response to temperature changes around resistor according
to a temperature coefficient of the resistance of the resistor. The
temperature regulator may include a precision resistive heater.
Inventors: |
Chou; Anthony I.; (Beacon,
NY) ; Kumar; Arvind; (Beacon, NY) ; Lee;
Sungjae; (Schenectady, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
56411102 |
Appl. No.: |
15/190254 |
Filed: |
June 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14990034 |
Jan 7, 2016 |
9400511 |
|
|
15190254 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01C 17/267 20130101;
H01C 3/04 20130101; H01C 17/232 20130101; H01L 22/14 20130101; G05D
23/24 20130101; G01K 7/16 20130101 |
International
Class: |
G05D 23/24 20060101
G05D023/24; G01K 7/16 20060101 G01K007/16 |
Claims
1. A method for controlling resistance value of a resistor in a
circuit comprising: retrieving, via a controller, a plurality of
parameters of the resistor from a non-volatile memory in the
circuit; detecting, via the controller, an operating temperature of
the resistor during circuit operation in field; generating, by the
controller, a temperature difference between the operating
temperature detected and a target temperature at which the resistor
has a target resistance value; producing, by the controller, a
control signal responsive to the temperature difference generated;
and transmitting the control signal to a temperature regulator
placed adjacent to the resistor to control the resistance value of
the resistor, wherein the temperature regulator comprises a front
end of the line (FEOL) cooler configured to change temperature of
the resistor in response to the control signal received from the
controller.
2. The method of claim 1, wherein the plurality of parameters of
the resistor comprises: an initial resistance value measured at
wafer test; an initial temperature associated with the initial
resistance value measured at the wafer test; the target resistance
value; and a temperature coefficient of the resistance measured at
the wafer test.
3. The method of claim 2, wherein the resistance value of the
resistor varies in response to temperature changes around the
resistor according to the temperature coefficient of the resistance
of the resistor.
4. The method of claim 1, wherein the detecting comprises detecting
the operating temperature of the resistor using a temperature
sensor.
5. (canceled)
6. (canceled)
7. The method of claim 1, wherein the generating comprises
calculating the target temperature of the resistor at which the
resistor has the target resistance value according to the initial
resistance value and the temperature coefficient of resistance of
the resistor measured at wafer test.
8. A control system for adjusting a resistance value of a resistor
in a circuit comprising: the resistor having a plurality of
parameters of the resistor stored in a non-volatile memory in the
circuit, wherein the plurality of parameters comprises an initial
resistance value measured at wafer test, an initial temperature
associated with the initial resistance value measured at the wafer
test, a target resistance value, and a temperature coefficient of
the resistance measured at the wafer test; a temperature regulator
located adjacent to the resistor; and a controller configured to:
retrieve the plurality of parameters of the resistor from the
non-volatile memory in the circuit; detect an operating temperature
of the resistor during circuit operation in field; generate a
temperature difference between the operating temperature and a
target temperature at which the resistor has the target resistance
value; produce a control signal responsive to the temperature
difference generated; and transmit the control signal to the
temperature regulator to adjust the resistance value of the
resistor, wherein the temperature regulator comprises a front end
of the line (FEOL) cooler configured to change temperature in
response to the control signal received from the controller.
9. The control system of claim 8, wherein the resistance value of
the resistor varies in response to temperature changes around the
resistor according to the temperature coefficient of the resistance
of the resistor.
10. The control system of claim 8, wherein the controller is
configured to detect the operating temperature of the resistor
using a temperature sensor.
11. (canceled)
12. (canceled)
13. The control system of claim 8, wherein the controller is
configured to calculate the target temperature of the resistor at
which the resistor has the target resistance value according to the
initial resistance value and the temperature coefficient of
resistance of the resistor measured at wafer test.
14. A circuit comprising the control system of claim 8.
15. A non-transitory computer storage medium having instructions
stored thereon which, when executed by a controller in a circuit,
cause the controller to perform: retrieving a plurality of
parameters of a resistor from a non-volatile memory in the circuit;
detecting an operating temperature of the resistor during circuit
operation in field; generating a temperature difference between the
operating temperature and a target temperature at which the
resistor has a target resistance value; producing a control signal
responsive to the temperature difference generated; and
transmitting the control signal to a temperature regulator placed
adjacent to the resistor to adjust the resistance value of the
resistor, wherein the temperature regulator comprises a front end
of the line (FEOL) cooler configured to change temperature in
response to the control signal received from the controller.
16. The non-transitory computer storage medium of claim 15, wherein
the plurality of parameters of the resistor comprises: the target
resistance value; an initial resistance value measured at wafer
test; an initial temperature associated with the initial resistance
value measured at the wafer test; and a temperature coefficient of
the resistance at the wafer test.
17. The non-transitory computer storage medium of claim 16, wherein
the resistance value of the resistor varies in response to
temperature changes around the resistor according to the
temperature coefficient of the resistance of the resistor.
18. The non-transitory computer storage medium of claim 15, wherein
the detecting comprises detecting the operating temperature of the
resistor using a temperature sensor.
19. (canceled)
20. The non-transitory computer storage medium of claim 15, wherein
the generating comprises calculating the target temperature of the
resistor at which the resistor has the target resistance value
according to the initial resistance value and the temperature
coefficient of resistance of the resistor measured at wafer test.
Description
DOMESTIC PRIORITY
[0001] This application is a continuation of and claims priority
from U.S. patent application Ser. No. 14/990,034, filed on Jan. 7,
2016, entitled "METHODS AND CONTROL SYSTEMS OF RESISTANCE
ADJUSTMENT OF RESISTORS", the entire contents of which are
incorporated herein by reference.
BACKGROUND
[0002] The present disclosure relates generally to integrated
circuits, and more particularly to methods and control systems of
resistance adjustment of resistors.
[0003] Resistors are important components of many analog electronic
circuits, digital electronic circuits, discrete electronic
circuits, and integrated circuits (IC). During the production of
these resistors, variations in the resistance values of these
resistors are generally unavoidable. These variations may cause
performance variations for the corresponding electronic circuits,
or differences of outputs of these electronic circuits. For
example, performance variation of a high-speed analog circuit such
as differential amplifier with a resistive load are mainly
determined by the process, voltage, and temperature (PVT)
variations of the precision resistors used in such high-speed
analog circuit. Consistent and precise resistance values of the
resistors used in these electronic circuits ensure consistent,
reliable and dependable performance of these electronic
circuits.
[0004] Therefore, heretofore unaddressed needs still exist in the
art to address the aforementioned deficiencies and
inadequacies.
SUMMARY
[0005] In an embodiment of the present invention, a method for
controlling a resistance value of a resistor in a circuit may
include: retrieving, via a controller, a set of parameters of the
resistor from a non-volatile memory in the circuit, detecting, via
the controller, an operating temperature of the resistor during
circuit operation in field using a temperature sensor, generating a
temperature difference between the operating temperature detected
and a target temperature at which the resistor has a target
resistance value, producing, via the controller, a control signal
responsive to the temperature difference generated, and applying
the control signal to a temperature regulator placed adjacent to
the resistor to adjust the resistance value of the resistor. The
resistance value of the resistor varies in response to temperature
changes around the resistor according to a temperature coefficient
of the resistance of the resistor. In certain embodiments, the
temperature regulator may include a precision resistive heater for
changing temperature in response to the control signal received
from the controller, and a front end of the line (FEOL) cooler for
changing temperature in response to the control signal received
from the controller.
[0006] In another embodiment of the present invention, a control
system for adjusting a resistance value of a resistor in a circuit
is provided. In certain embodiments, the control system may include
the resistor, and a controller. The resistance value of the
resistor varies in response to temperature changes around the
resistor according to the temperature coefficient of the resistance
of the resistor. In certain embodiments, the controller is
configured to: retrieve the set of parameters of the resistor from
the non-volatile memory in the circuit, detect an operating
temperature of the resistor during circuit operation in field,
generate a temperature difference between the operating temperature
and a target temperature at which the resistor has the target
resistance value, produce a control signal responsive to the
temperature difference generated, and apply the control signal to a
temperature regulator placed adjacent to the resistor to adjust the
resistance value of the resistor.
[0007] In yet another embodiment of the present invention, the
present disclosure relates to a non-transitory computer storage
medium. In certain embodiments, the non-transitory computer storage
medium stores instructions. When these instructions are executed by
a controller in a circuit, these instructions cause the controller
to perform: retrieving a set of parameters of a resistor from a
non-volatile memory in the circuit, detecting an operating
temperature of the resistor during circuit operation in field,
generating a temperature difference between the operating
temperature and a target temperature at which the resistor has a
target resistance value, producing a control signal responsive to
the temperature difference generated, and applying the control
signal to a temperature regulator placed adjacent to the resistor
to adjust the resistance value of the resistor.
[0008] These and other aspects of the present disclosure will
become apparent from the following description of the preferred
embodiment taken in conjunction with the following drawings and
their captions, although variations and modifications therein may
be affected without departing from the spirit and scope of the
novel concepts of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0010] FIG. 1 is a graphical illustration of a positive temperature
coefficient of resistance (TCR) of a resistor and a negative TCR of
another resistor in accordance with exemplary embodiments of the
present disclosure;
[0011] FIG. 2 is a structural view of an exemplary control system
for adjusting resistance value of a resistor in accordance with one
exemplary embodiment of the present disclosure;
[0012] FIG. 3 is a structural view of another exemplary control
system for adjusting resistance value of a resistor in accordance
with another exemplary embodiment of the present disclosure;
and
[0013] FIG. 4 is a flow chart of an exemplary method of practicing
an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0014] The present disclosure is more particularly described in the
following examples that are intended as illustrative only since
numerous modifications and variations therein will be apparent to
those skilled in the art. Various embodiments of the disclosure are
now described in detail. Referring to the drawings, like numbers,
if any, indicate like components throughout the views. As used in
the description herein and throughout the claims that follow, the
meaning of "a", "an", and "the" includes plural reference unless
the context clearly dictates otherwise. Also, as used in the
description herein and throughout the claims that follow, the
meaning of "in" includes "in" and "on" unless the context clearly
dictates otherwise. Moreover, titles or subtitles may be used in
the specification for the convenience of a reader, which shall have
no influence on the scope of the present disclosure. Additionally,
some terms used in this specification are more specifically defined
below.
[0015] The terms used in this specification generally have their
ordinary meanings in the art, within the context of the disclosure,
and in the specific context where each term is used. Certain terms
that are used to describe the disclosure are discussed below, or
elsewhere in the specification, to provide additional guidance to
the practitioner regarding the description of the disclosure. It
will be appreciated that same thing can be said in more than one
way. Consequently, alternative language and synonyms may be used
for any one or more of the terms discussed herein, nor is any
special significance to be placed upon whether or not a term is
elaborated or discussed herein. The use of examples anywhere in
this specification including examples of any terms discussed herein
is illustrative only, and in no way limits the scope and meaning of
the disclosure or of any exemplified term. Likewise, the disclosure
is not limited to various embodiments given in this
specification.
[0016] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure pertains. In the
case of conflict, the present document, including definitions will
control.
[0017] As used herein, "plurality" means two or more. The terms
"comprising," "including," "carrying," "having," "containing,"
"involving," and the like are to be understood to be open-ended,
i.e., to mean including but not limited to.
[0018] The term computer program, as used above, may include
software, firmware, and/or microcode, and may refer to programs,
routines, functions, classes, and/or objects. The term shared, as
used above, means that some or all code from multiple modules may
be executed using a single (shared) processor.
[0019] The term "TCR" is temperature coefficient of resistance of a
resistor.
[0020] The term "CML" stands for current mode logic, and it is
generally used to represent differential amplifier having current
source for biasing, pair of transistors and their corresponding
load resistors to amplify differential signal.
[0021] The apparatuses and methods described herein may be
implemented by one or more computer programs executed by one or
more processors. The computer programs include processor-executable
instructions that are stored on a non-transitory tangible computer
readable medium. The computer programs may also include stored
data. Non-limiting examples of the non-transitory tangible computer
readable medium are nonvolatile memory, magnetic storage, and
optical storage.
[0022] The present disclosure will now be described more fully
hereinafter with reference to the accompanying drawings FIGS. 1-4,
in which certain exemplary embodiments of the present disclosure
are shown. The present disclosure may, however, be embodied in many
different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the disclosure to those skilled in
the art.
[0023] Resistors are usually important components of any analog
electronic circuits, digital electronic circuits, discrete
electronic circuit, and integrated circuits (IC). During the
production of these resistors either as discrete components, or as
a part of an integrated circuit, variations in resistance values of
these resistors are generally unavoidable. These variations may
cause performance variations for the corresponding electronic
circuits, or differences of outputs of these electronic circuits.
For example, performance variation of a high-speed analog circuit
such as differential amplifier with resistive load are mainly
determined by the process, voltage, and temperature (PVT)
variations of precision resistors used in such high-speed analog
circuit. Consistent and precise resistance values of the resistors
used in these electronic circuits ensure consistent, reliable and
dependable performance of these electronic circuits.
[0024] Since the variations in resistance values of these resistors
are generally unavoidable during the production process, it is
desirable to have certain built-in mechanism to compensate the
variations to ensure the resistance values are consistent and
precise when the resistors are used during circuit operation in
field.
[0025] A temperature coefficient describes the relative change of a
physical property that is associated with a given change in
temperature. For a property resistance R that changes by dR when
the temperature changes by dT, the temperature coefficient .alpha.
is defined by
dR R = .alpha. dT . ##EQU00001##
[0026] wherein .alpha. has the dimension of an inverse temperature
and can be expressed e.g. in 1/K or K.sup.-1.
[0027] If the temperature coefficient itself does not vary too much
with temperature, a linear approximation can be used to determine
the value R of a property at a temperature T, given its value
R.sub.0 at a reference temperature T.sub.0:
R(T)=R(T.sub.0)(1+.alpha..DELTA.T),
[0028] where .DELTA.T is the difference between T and T.sub.0. For
strongly temperature-dependent .alpha., this approximation is only
useful for small temperature differences .DELTA.T.
[0029] Referring now to FIG. 1, a graphical illustration of a
positive TCR curve 102 of a resistor and a negative TCR curve 104
of another resistor are shown in accordance with exemplary
embodiments of the present disclosure. The positive TCR curve 102
refers to materials that experience an increase in electrical
resistance when their temperature is raised. Materials which have
useful engineering applications usually show a relatively rapid
increase with temperature, i.e. a higher coefficient. The higher
the coefficient, the greater an increase in electrical resistance
for a given temperature increase. The negative TCR curve 104 refers
to materials that experience a decrease in electrical resistance
when their temperature is raised. Materials which have useful
engineering applications usually show a relatively rapid decrease
with temperature, i.e. a lower coefficient. The lower the
coefficient, the greater a decrease in electrical resistance for a
given temperature increase.
[0030] A resistor that exhibits either positive TCR or negative TCR
may be used to adjust the resistance value of the resistor by
adjusting the surrounding temperature of the resistor within a
certain temperature range.
[0031] In one aspect, the present disclosure relates to a control
system 200 for adjusting a resistance value of a resistor 220 in a
circuit. FIG. 2 shows a structural view of the exemplary control
system 200 for adjusting resistance value of a resistor 220 in
accordance with one exemplary embodiment of the present disclosure.
The control system 200 may include: a resistor 220, a temperature
regulator 210, a controller 260, and a substrate 240. The resistor
220 has a first terminal electrically coupled to a first via 222,
and an opposite, second terminal electrically coupled to a second
via 224. The first via 222 is electrically coupled to a first
terminal 232 of the resistor 220, and the second via 224 is
electrically coupled to a second terminal 234 of the resistor 220.
The resistor 220 is a part of an electronic circuit. The electronic
circuit may be a discrete electronic circuit, or an integrated
circuit.
[0032] In certain embodiments, the temperature regulator 210 is a
precision resistive heater. The temperature regulator 210 may
include a first terminal 212 and a second terminal 214. The first
terminal 212 and the second terminal 214 of the temperature
regulator 210 are configured to connect to the controller 260 to
receive control voltage/current to adjust the temperature of the
temperature regulator 210. In certain embodiments, the precision
resistive heater may include flexible resistive foil heaters,
precision resistive heating wires, and precision resistive sheets.
The precision resistive heater may be driven by the controller 260
using direct current (DC), alternating current (AC), and low
frequent pulse-width-modulation (PWM) voltage sources.
[0033] The temperature regulator 210 may be placed under, or
adjacent to the resistor 220, and is used to generate certain
amount of heat to change the temperature of the resistor 220 when
the temperature regulator 210 is energized by the controller 260.
The control system 200 may include a temperature sensor 250 to
measure the temperature of the resistor 220 while the electronic
circuit is in operation.
[0034] In certain embodiments, the controller 260 is coplanar with
temperature regulator 210. The temperature regulator 210 may
include a precision resistive heater, or an FEOL cooler. In one
embodiment, the substrate 240 may be a bulk silicon substrate. In
another embodiment, the substrate 240 may be a silicon on insulator
(SOI) and silicon substrate.
[0035] According to the design of the electronic circuit, the
resistor 220 may be given a target resistance value, R.sub.t.
However, when the resistor 220 is chosen to be installed in a
discrete electronic circuit, or is integrated in an integrated
circuit (IC) chip, an actual resistance value R.sub.1 may not be
exactly the same as the target resistance value, R.sub.t. The
resistance discrepancy (R.sub.t-R.sub.1) may cause the performance
of the electronic circuit to deteriorate.
[0036] In one embodiment, the temperature sensor 250, the
temperature regulator 210, and the controller 260 are placed under
or adjacent to the resistor 220 to compensate the resistance
discrepancy (R.sub.t-R.sub.1). For example, in one embodiment, the
resistance discrepancy (R.sub.t-R.sub.1)>0, where the R.sub.1 is
less than the target resistance R.sub.t. The controller 260 should
raise the temperature of the resistor 220, hence raise the
resistance value of the resistor 220 to compensate the resistance
discrepancy (R.sub.t-R.sub.1). The controller 260 first retrieves a
set of parameters of the resistor 220 from a non-volatile memory of
the electronic circuit. The set of parameters of the resistor 220
may include: the target resistance value R.sub.t, an initial
resistance value R.sub.0 measured at wafer test, an initial
temperature associated with the initial resistance value measured
at wafer test, and a temperature coefficient of the resistance
(TCR) measured at the wafer test. Then the controller 260 detects
an operating temperature of the resistor 220 during circuit
operation in field using the temperature sensor 250, generates a
temperature difference between the operating temperature detected
and a target temperature at which the resistor 220 has the target
resistance value, produces a control signal responsive to the
temperature difference generated, and then applies the control
signal to the temperature regulator 210 to adjust the resistance
value of the resistor 220 by changing the temperature of the
resistor 220 to raise the resistance value of the resistor 220
until the resistance value of the resistor 220 reaches the target
resistance R.sub.t.
[0037] In another embodiment, the resistance discrepancy
(R.sub.t-R.sub.1)<0, where the R.sub.1 is greater than the
target resistance R.sub.t. The controller 260 should reduce the
temperature of the resistor 220, hence reduce the resistance value
of the resistor 220 to compensate the resistance discrepancy
(R.sub.t-R.sub.1). The controller 260 first retrieves a set of
parameters of the resistor 220 from the non-volatile memory of the
electronic circuit. Then the controller 260 detects the operating
temperature of the resistor 220 during circuit operation in field
using the temperature sensor 250, generates a temperature
difference between the operating temperature detected and a target
temperature at which the resistor 220 has the target resistance
value, produces a control signal responsive to the temperature
difference generated, and then applies the control signal to the
temperature regulator 210 to adjust the resistance value of the
resistor 220 by changing the temperature of the resistor 220 to
reduce the resistance value of the resistor 220 until the
resistance value of the resistor 220 reaches the target resistance
R.sub.t.
[0038] In the embodiments described above, a resistor that has a
positive TCR curve is used. The resistance value of the resistor
increases as the temperature of the resistor increases. Here a
precision resistive heater may be used to change the resistance
value of the resistor.
[0039] In other embodiments, a resistor that has a negative TCR
curve may be used. The resistance value of the resistor decreases
as the temperature of the resistor increases. Here a front end of
line (FEOL) cooler such as forward biased PN junction Peltier
cooler may be used to change the resistance value of the
resistor.
[0040] FIG. 3 shows a structural view of another exemplary on-chip
control system 300 for adjusting resistance value of a resistor 320
in an integrated circuit in accordance with one exemplary
embodiment of the present disclosure. The control system 300 may
include: a resistor 320, a temperature regulator 310, a controller
360, and a substrate 340. The resistor 320 has a first terminal
electrically coupled to a first via 322, and an opposite, second
terminal electrically coupled to a second via 324. The first via
322 is electrically coupled to a first terminal 332 of the resistor
320, and the second via 324 is electrically coupled to a second
terminal 334 of the resistor 320. The resistor 320 is a part of the
integrated circuit.
[0041] In certain embodiments, the controller 360 is coplanar with
temperature regulator 310. The temperature regulator 310 may
include a precision resistive heater, or an FEOL cooler. In one
embodiment, the substrate 340 may be a bulk silicon substrate. In
another embodiment, the substrate 340 may be a silicon on insulator
(SOI) and silicon substrate.
[0042] In certain embodiments, the temperature regulator 310 is a
precision resistive heater. The temperature regulator 310 may
include a first terminal 312 and a second terminal 314. The first
terminal 312 and the second terminal 314 of the temperature
regulator 310 are configured to connect to the controller 360 to
receive control voltage/current to adjust the temperature of the
temperature regulator 310. The precision resistive heater may be
driven by the controller 260 using direct current (DC), alternating
current (AC), and low frequent pulse-width-modulation (PWM) voltage
sources.
[0043] The temperature regulator 310 may be placed under, or
adjacent to the resistor 320, and is used to generate certain
amount of heat to change the temperature of the resistor 320 when
the temperature regulator 310 is energized by the controller 360.
The control system 300 may include a temperature sensor 350 to
measure the temperature of the resistor 320 while the electronic
circuit is in operation. The operating principle here are parallel
to the ones described in previous sections, and will not be
repeated here for brevity reasons.
[0044] In certain embodiments, the temperature regulator 310 is
biased, and its parasitic capacitance impact can be substantial in
the integrated circuit. Due to the distributed nature of parasitic
resistance and capacitance (RC), such parasitic capacitance may be
neutralized or minimized by placing the temperature regulator 310
in certain location when the integrated circuit is designed. For
example, as shown in FIG. 3, the resistor 320 is used in a
differential amplifier such as current mode logic (CIVIL). The
first terminal 332 of the resistor 320 is electrically coupled to
an output terminal of the differential amplifier, and the second
terminal 334 of the resistor 320 is electrically coupled to an IC
power supply pin VDD or ground (GND). In order to minimize the
parasitic capacitance of the integrated circuit, the temperature
regulator 310, or the precision resistive heater, is placed near
the second terminal 334, i.e., near IC power supply pin VDD or the
ground (GND) to minimize the potential impact of the parasitic
capacitance.
[0045] In another aspect, the present disclosure relates to a
method for controlling resistance value of a resistor 220 in a
circuit. Referring now to FIGS. 2 and 4, the structural view of the
exemplary control system 200 for adjusting resistance value of the
resistor 220 and a flow chart of an exemplary method 400 of
adjusting resistance value of the resistor 220 are shown according
to certain embodiments of the present disclosure. As shown at block
402, the controller 260 retrieves a set of parameters of the
resistor 220. The set of parameters is stored in a non-volatile
memory device (not shown in FIG. 2) of the electronic circuit. In
certain embodiments, the set of parameters may include: a target
resistance value, an initial resistance value measured at wafer
test, an initial temperature associated with the initial resistance
value measured at the wafer test, and a temperature coefficient of
the resistance (TCR). The resistor 220 may be a resistor that has
positive temperature coefficient of resistance, or a thermistor.
The resistance value of the resistor varies in response to
temperature changes around the resistor 220 according to the
temperature coefficient of the resistance of the resistor 220.
[0046] Next, as shown at block 404, the controller 260 detects
current operating temperature of the resistor 220 during circuit
operation in field. The controller 260 may use the current
operating temperature of the resistor 220 to calculate current
resistance value of the resistor 220 according to the temperature
coefficient of the resistance of the resistor 220 retrieved through
block 402.
[0047] As shown at block 406, the controller 260 generates a
temperature difference between the current operating temperature
detected and a target temperature at which the resistor 220 has the
target resistance value. The target temperature is calculated based
on the initial resistance value and the temperature coefficient of
resistance of the resistor 220.
[0048] As shown at block 408, the controller 260 produces a control
signal responsive to the temperature difference generated. The
controller 260 first decides whether the temperature of the
resistor 220 should go up or down based on the temperature
difference detected. When the resistor has a positive TCR, and the
when the target resistance value is higher than the current
resistance value, then the controller 260 may increase the voltage
or current to the temperature regulator 210 to increase the
resistance value of the resistor 220. When the resistor has a
negative TCR, and the when the target resistance value is less than
the current resistance value, then the controller 260 may increase
the voltage or current to the temperature regulator 210 to decrease
the resistance value of the resistor 220.
[0049] At block 410, the controller 260 checks whether the current
resistance value of the resistor 220 has reached the target
resistance value. When the current resistance value of the resistor
220 has reached the target resistance value, then the method 400
continues to block 412. When the current resistance value of the
resistor 220 is still greater than or less than the target
resistance value, then the method 400 continues to block 406 to
continue the resistance value adjustment until the current
resistance value of the resistor 220 reaches the target resistance
value.
[0050] At block 412, the controller 260 continues to monitor and
adjust the current resistance value of the resistor 220 when
necessary, until the electronic circuit is shut down.
[0051] In yet another aspect, the present disclosure relates to a
non-transitory computer storage medium. In certain embodiments, the
non-transitory computer storage medium stores instructions. When
these instructions are executed by a controller 260 in a circuit,
these instructions cause the controller 260 to perform: retrieving
a set of parameters of a resistor 220 from a non-volatile memory in
the circuit, detecting an operating temperature of the resistor 220
during circuit operation in field, generating a temperature
difference between the operating temperature and a target
temperature at which the resistor 220 has a target resistance
value, producing a control signal responsive to the temperature
difference generated, and applying the control signal to a
temperature regulator 210 placed adjacent to the resistor 220 to
adjust the resistance value of the resistor 220.
[0052] In certain embodiments, the set of parameters of the
resistor 220 may include: the target resistance value, an actual
resistance value measured at wafer test, and a temperature
coefficient of the resistance at the wafer test. In certain
embodiments, the resistance value of the resistor 220 varies in
response to temperature changes around the resistor 220 according
to the temperature coefficient of the resistance of the resistor
220.
[0053] In certain embodiments, the non-transitory computer storage
medium may include instructions for detecting the temperature of
the resistor 220 using a temperature sensor 250. The temperature
regulator 210 may be a precision resistive heater for changing
temperature in response to the control signal received from the
controller 260, and a front end of the line (FEOL) cooler for
changing temperature in response to the control signal received
from the controller 260.
[0054] In certain embodiments, the non-transitory computer storage
medium may include instructions for calculating the target
temperature of the resistor 220 at which the resistor 220 has the
target resistance value according to the actual resistance value
and the temperature coefficient of resistance of the resistor 220
measured at wafer test.
[0055] The present invention may be a computer system, a method,
and/or a computer program product. The computer program product may
include a computer readable storage medium (or media) having
computer readable program instructions thereon for causing a
processor to carry out aspects of the present invention.
[0056] The computer readable storage medium can be a tangible
device that can retain and store instructions for use by an
instruction execution device. The computer readable storage medium
may be, for example, but is not limited to, an electronic storage
device, a magnetic storage device, an optical storage device, an
electromagnetic storage device, a semiconductor storage device, or
any suitable combination of the foregoing. A non-exhaustive list of
more specific examples of the computer readable storage medium
includes the following: a portable computer diskette, a hard disk,
a random access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), a static
random access memory (SRAM), a portable compact disc read-only
memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a
floppy disk, a mechanically encoded device such as punch-cards or
raised structures in a groove having instructions recorded thereon,
and any suitable combination of the foregoing. A computer readable
storage medium, as used herein, is not to be construed as being
transitory signals per se, such as radio waves or other freely
propagating electromagnetic waves, electromagnetic waves
propagating through a waveguide or other transmission media (e.g.,
light pulses passing through a fiber-optic cable), or electrical
signals transmitted through a wire.
[0057] Computer readable program instructions described herein can
be downloaded to respective computing/processing devices from a
computer readable storage medium or to an external computer or
external storage device via a network, for example, the Internet, a
local area network, a wide area network and/or a wireless network.
The network may comprise copper transmission cables, optical
transmission fibers, wireless transmission, routers, firewalls,
switches, gateway computers and/or edge servers. A network adapter
card or network interface in each computing/processing device
receives computer readable program instructions from the network
and forwards the computer readable program instructions for storage
in a computer readable storage medium within the respective
computing/processing device.
[0058] Computer readable program instructions for carrying out
operations of the present invention may be assembler instructions,
instruction-set-architecture (ISA) instructions, machine
instructions, machine dependent instructions, microcode, firmware
instructions, state-setting data, or either source code or object
code written in any combination of one or more programming
languages, including an object oriented programming language such
as Smalltalk, C++ or the like, and conventional procedural
programming languages, such as the "C" programming language or
similar programming languages. The computer readable program
instructions may execute entirely on the user's computer, partly on
the user's computer, as a stand-alone software package, partly on
the user's computer and partly on a remote computer or entirely on
the remote computer or server. In the latter scenario, the remote
computer may be connected to the user's computer through any type
of network, including a local area network (LAN) or a wide area
network (WAN), or the connection may be made to an external
computer (for example, through the Internet using an Internet
Service Provider). In some embodiments, electronic circuitry
including, for example, programmable logic circuitry,
field-programmable gate arrays (FPGA), or programmable logic arrays
(PLA) may execute the computer readable program instructions by
utilizing state information of the computer readable program
instructions to personalize the electronic circuitry, in order to
perform aspects of the present invention.
[0059] Aspects of the present invention are described herein with
reference to flowchart illustrations and/or block diagrams of
methods, and computer program products according to embodiments of
the invention. It will be understood that each block of the
flowchart illustrations and/or block diagrams, and combinations of
blocks in the flowchart illustrations and/or block diagrams, can be
implemented by computer readable program instructions.
[0060] These computer readable program instructions may be provided
to a processor of a general purpose computer, special purpose
computer, or other programmable data processing apparatus to
produce a machine, such that the instructions, which execute via
the processor of the computer or other programmable data processing
apparatus, create means for implementing the functions/acts
specified in the flowchart and/or block diagram block or blocks.
These computer readable program instructions may also be stored in
a computer readable storage medium that can direct a computer, a
programmable data processing apparatus, and/or other devices to
function in a particular manner, such that the computer readable
storage medium having instructions stored therein comprises an
article of manufacture including instructions which implement
aspects of the function/act specified in the flowchart and/or block
diagram block or blocks.
[0061] The computer readable program instructions may also be
loaded onto a computer, other programmable data processing
apparatus, or other device to cause a series of operational steps
to be performed on the computer, other programmable apparatus or
other device to produce a computer implemented process, such that
the instructions which execute on the computer, other programmable
apparatus, or other device implement the functions/acts specified
in the flowchart and/or block diagram block or blocks.
[0062] The flowchart and block diagrams in the Figures illustrate
the architecture, functionality, and operation of possible
implementations of systems, methods, and computer program products
according to various embodiments of the present invention. In this
regard, each block in the flowchart or block diagrams may represent
a module, segment, or portion of instructions, which comprises one
or more executable instructions for implementing the specified
logical function(s). In some alternative implementations, the
functions noted in the block may occur out of the order noted in
the figures. For example, two blocks shown in succession may, in
fact, be executed substantially concurrently, or the blocks may
sometimes be executed in the reverse order, depending upon the
functionality involved. It will also be noted that each block of
the block diagrams and/or flowchart illustration, and combinations
of blocks in the block diagrams and/or flowchart illustration, can
be implemented by special purpose hardware-based systems that
perform the specified functions or acts or carry out combinations
of special purpose hardware and computer instructions.
[0063] The descriptions of the various embodiments of the present
invention have been presented for purposes of illustration, but are
not intended to be exhaustive or limited to the embodiments
disclosed. Many modifications and variations will be apparent to
those of ordinary skill in the art without departing from the scope
and spirit of the described embodiments. The terminology used
herein was chosen to best explain the principles of the
embodiments, the practical application or technical improvement
over technologies found in the marketplace, or to enable others of
ordinary skill in the art to understand the embodiments disclosed
herein.
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