CN105577134B - Transmission line drive circuit for adaptive correction impedance matching - Google Patents
Transmission line drive circuit for adaptive correction impedance matching Download PDFInfo
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- CN105577134B CN105577134B CN201410527907.3A CN201410527907A CN105577134B CN 105577134 B CN105577134 B CN 105577134B CN 201410527907 A CN201410527907 A CN 201410527907A CN 105577134 B CN105577134 B CN 105577134B
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Abstract
The present invention proposes a kind of transmission line drive circuit for adaptive correction impedance matching.The transmission line drive circuit includes: the transmission line driving amplifier with the first transmission end and the second transmission end；First signal node；Second signal node；The first adjustable resistance between the first transmission end and the first signal node；The second adjustable resistance between the second transmission end and second signal node；Internal node；The first divider resistance between the first signal node and internal node；The second divider resistance between second signal node and internal node；Comparison circuit, for the partial pressure on comparison reference voltage and internal node, to generate comparison signal；And adjustment circuit, for at least one of resistance value according to comparison signal adjustment the first adjustable resistance and the second adjustable resistance, so that the transmission line drive circuit and the equivalent load circuit reach the state of impedance matching.
Description
Technical field
It is the present invention relates to transmission line drive circuit technical field, in particular to a kind of for adaptive correction impedance matching
Transmission line drive circuit.
Background technique
In order to transmit signal and energy efficient, ideally circuit of output terminal and inlet circuit preferably work in impedance
Matching status.Also that is, the internal resistance of circuit of output terminal should be equal to the input impedance of circuit of output terminal, and the output of circuit of output terminal
Impedance should be equal to the impedance of inlet circuit (general also known as to load).When the resistance of both circuit of output terminal and inlet circuit
It is anti-when matching each other, maximum power transmission will be obtained.Conversely, when both circuit of output terminal and inlet circuit impedance not
Timing not only cannot get maximum power transmission, it is also possible to generate damage to circuit.
For example, when the impedance mismatch of both circuit of output terminal and inlet circuit, the differential input of circuit of output terminal
Out electric current have it is asymmetric happen, and then the problem of lead to electromagnetic interference (EMI).In addition, when circuit of output terminal with it is defeated
When the impedance mismatch of both input circuits, the reflection loss (Return Loss) of system also be will increase.
Summary of the invention
In view of this, the case where circuit of output terminal and inlet circuit impedance mismatch how is effectively mitigated or eliminated, with
Reduce electromagnetic interference and the problem of reflection loss, actually industry problem to be solved.
This specification provides a kind of embodiment of transmission line drive circuit for adaptive correction impedance matching, packet
Contain: there is a transmission line driving amplifier one first transmission end for providing a pair of differential formula transmission signal to pass with one second
Defeated end；One first signal node, for coupling one first load end signal node of an equivalent load circuit；One second signal section
Point, for coupling one second load end signal node of the equivalent load circuit；One first adjustable resistance is located at first transmission
On signal path between end and first signal node；One second adjustable resistance is located at second transmission end and second letter
On signal path between number node；One internal node；One first divider resistance, wherein the one first of first divider resistance
End is coupled on the signal path between first adjustable resistance and first signal node, and the 1 of first divider resistance the
Two ends are coupled to the internal node；One second divider resistance, wherein a first end of second divider resistance be coupled to this second
On signal path between adjustable resistance and the second signal node, and to be coupled to this interior for a second end of second divider resistance
Portion's node；One comparison circuit is coupled to the internal node, is arranged to compare one point on a reference voltage and the internal node
Pressure, to generate a comparison signal；And an adjustment circuit, be coupled to first adjustable resistance, second adjustable resistance, with the ratio
Compared with circuit, it is arranged to adjust at least one of of first adjustable resistance and second adjustable resistance according to the comparison signal
Resistance value, so that the transmission line drive circuit and the equivalent load circuit reach the state of impedance matching.
One of the advantages of above-described embodiment is that transmission line drive circuit can reduce or eliminate the first signal node and the second letter
The asymmetric situation of output electric current between number node, and then the problem of reduce electromagnetic interference and reflection loss.
Another advantage of above-described embodiment is transmission line drive circuit adaptability, effectively correction and equivalent load electricity
Impedance mismatch situation between road, and suitable for the framework of various circuit of output terminal, therefore its application range is quite extensive.
Other advantages of the invention will be described in detail by the following description and attached drawing.
Detailed description of the invention
Fig. 1 is the simplified functional block diagram of transmission line drive circuit of one embodiment of the invention.
Description of symbols:
100 transmission line drive circuits
110 transmission line driving amplifiers
122,124 signal node
132,134 adjustable resistance
140 internal nodes
152,154 divider resistance
160 comparison circuits
170 adjustment circuits
180 equivalent load circuits
181,182 load end signal node
183,184 load end equivalent capacity
185,186 load end equivalent impedance
Specific embodiment
Illustrate the embodiment of the present invention below in conjunction with relevant drawings.In the accompanying drawings, identical label indicate it is identical or
Similar element or method flow.
Fig. 1 is the transmission line drive circuit (transmission line driver circuit) of one embodiment of the invention
100 simplified functional block diagrams.As shown in Figure 1, transmission line drive circuit 100 includes a transmission line driving amplifier
(transmission line driving amplifier) 110, one first signal node (signal node) 122,1
Binary signal node 124, one first adjustable resistance 132, one second adjustable resistance 134, an internal node 140, one first partial pressure electricity
Hinder (divider resistor) 152, one second divider resistance 154, a comparison circuit 160 and an adjustment circuit 170.
Transmission line driving amplifier 110 has for providing one first transmission end and one the of a pair of differential formula transmission signal
Two transmission end.In the present embodiment, the first transmission end above-mentioned is the positive output end of transmission line driving amplifier 110, and aforementioned
The second transmission end be transmission line driving amplifier 110 negative output terminal.First signal node 122 is for coupling an equivalent load
The one first load end signal node (load-end signal node) of circuit (equivalent load circuit) 180
181.Second signal node 124 is used to couple one second load end signal node 182 of equivalent load circuit 180.Practical operation
In, the first signal node 122 can be respectively coupled to the first load by various pairs of signal wires with second signal node 124
End signal node 181 and the second load end signal node 182.In running, the first signal node 122 and second signal node
124 differential types that can generate transmission line driving amplifier 110 transmit signal, are respectively sent to the of equivalent load circuit 180
One load end signal node 181 and the second load end signal node 182.
" equivalent load circuit " word in the application documents of present patent application, can be amplification in practical application
The various inlet circuits such as device, circuit under test, antenna or receiver.It, especially will be equivalent in Fig. 1 for the sake of for convenience of description
The function block of load circuit 180 is by simplifying.In equivalent load circuit 180, it is negative that load end equivalent capacity 183 represents first
The equivalent capacity on the signal path at 181 place of end signal node is carried, load end equivalent impedance 185 represents the first load end signal
The equivalent impedance on signal path where node 181.Similarly, load end equivalent capacity 184 represents the second load end signal
The equivalent capacity on signal path where node 182, load end equivalent impedance 186 represent the second load end signal node 182
Equivalent impedance on the signal path at place.
In addition, the first signal node 122 above-mentioned and second signal node 124, can be a medium in practical application
A pair of differential formula signal node in relevant interface (medium dependent interface, MDI), can be a cross connection type
A pair of differential formula signal section in medium dependent interfaces (medium dependent interface crossover, MDIX)
Point, a pair of differential formula signal node being also possible in other signal transmission interfaces.Similarly, the first load end signal above-mentioned
Node 181 and the second load end signal node 182 can be a pair of differential formula letter in medium dependent interfaces in practical application
Number node, can be a pair of differential formula signal node in cross connection type medium dependent interfaces, is also possible to the transmission of other signals and connects
A pair of differential formula signal node in mouthful.
In the present embodiment, a first end of the first adjustable resistance 132 is coupled to the first of transmission line driving amplifier 110
Transmission end, and a second end of the first adjustable resistance 132 is coupled to the first signal node 122.The one of second adjustable resistance 134
One end is coupled to the second transmission end of transmission line driving amplifier 110, and a second end of the second adjustable resistance 134 is coupled to
Binary signal node 124.One first end of the first divider resistance 152 is coupled to the first adjustable resistance 132 and the first signal node 122
Between signal path on, and a second end of the first divider resistance 152 is coupled to internal node 140.Second divider resistance 154
A first end be coupled on the signal path between the second adjustable resistance 134 and second signal node 124, and second partial pressure electricity
One second end of resistance 154 is coupled to internal node 140.
In other words, in transmission line drive circuit 100, the first adjustable resistance 132 is located at the first transmission end and the first signal
On signal path between node 122, the second adjustable resistance 134 is between the second transmission end and second signal node 124
On signal path, the first divider resistance 152 is on the signal path between the first signal node 122 and internal node 140, and
Second divider resistance 154 is on the signal path between second signal node 124 and internal node 140.It is internal in running
Node 140 can provide a partial pressure VPN, and the size of partial pressure VPN depends on the first divider resistance 152 and the second divider resistance
154 resistance proportion between the two.
Comparison circuit 160 is coupled to internal node 140, is arranged to compare on a reference voltage VCM and internal node 140
VPN is divided, to generate a comparison signal CMP.In the present embodiment, the positive input terminal of comparison circuit 160 is coupled to one with reference to electricity
VCM is pressed, and the negative input end of comparison circuit 160 is coupled to internal node 140.
In practical operation, comparison circuit 160 can be with a hysteresis comparator (hysteresis comparator) come real
It is existing, and the reference voltage VCM that the positive input terminal of comparison circuit 160 is coupled, the offer of transmission line driving amplifier 110 is provided
One common-mode voltage (common mode voltage).
Adjustment circuit 170 is coupled to the first adjustable resistance 132, the second adjustable resistance 134 and comparison circuit 160, is arranged to
At least one of resistance value according to comparison signal CMP adjustment the first adjustable resistance 132 and the second adjustable resistance 134.
In practical operation, adjustment circuit 170 can use each of various logic circuit, digital circuit, counter or aforementioned circuit
Kind combination is to realize.It in certain embodiments, also may include that can store the storage circuits of data (not draw in adjustment circuit 170
Show), for example, register, buffer, trigger, memory etc..
In ideal conditions, when the impedance matching of 180 the two of transmission line drive circuit 100 and equivalent load circuit,
Voltage absolute value of the difference between the voltage VP and VPN at 152 both ends of the first divider resistance, it should can be with the second divider resistance 154
Voltage absolute value of the difference between the voltage VN and VPN at both ends is equal.
Therefore, when the comparison signal CMP that comparison circuit 160 exports vibrates between positive and negative configuration, 170 meeting of adjustment circuit
Transmission line drive circuit 100 is not matched with the impedance of both equivalent load circuits 180 at this time for judgement.In the case, it adjusts
Circuit 170 can be by adjusting the side of at least one of resistance value of the first adjustable resistance 132 and the second adjustable resistance 134
Formula, the output impedance of Lai Jiaozheng transmission line drive circuit 100 make transmission line drive circuit 100 and equivalent load circuit whereby
Both 180 reach the state of impedance matching.
For example, when the comparison signal CMP that comparison circuit 160 exports vibrates between positive and negative configuration, 170 meeting of adjustment circuit
At least one of resistance value of the first adjustable resistance 132 and the second adjustable resistance 134 is adjusted, so that comparison circuit 160
The comparison signal CMP of output stablizes in one of positive configuration and negative configuration.
Reference voltage VCM, which is only able to display, in comparison signal CMP divides the relatively large of both VPN on internal node 140
In small some embodiments, adjustment circuit 170 can gradually adjust the resistance of the first adjustable resistance 132 in multiple calibration cycles
The resistance value of value or the second adjustable resistance 134, until comparison signal CMP stabilization is in one of positive configuration and negative configuration
Only.
The relative size of both partial pressure VPN on reference voltage VCM and internal node 140 can be shown in comparison signal CMP
And in some embodiments of measures of dispersion, adjustment circuit 170 can also be in a single calibration cycle directly by the first adjustable electric
The resistance value of resistance 132 is adjusted to a first object value, or the resistance value of the second adjustable resistance 134 is directly adjusted to one second
Target value, so that comparison signal CMP stablizes in one of positive configuration and negative configuration.For example, can by reference voltage VCM with
The measures of dispersion of partial pressure VPN on internal node 140 and the corresponding relationship of resistance value adjustment amount, in the form of the table of comparisons (not being painted)
It indicates, and has previously been stored in the storage circuit of adjustment circuit 170.In running, adjustment circuit 170 can be according to reference voltage
The measures of dispersion of partial pressure VPN on VCM and internal node 140 inquires the table of comparisons to learn resistance value adjustment amount appropriate, and according to
To adjust at least one of resistance value of the first adjustable resistance 132 and the second adjustable resistance 134.
By preceding description it is found that the comparison circuit 160 in transmission line drive circuit 100 can detect transmission line drive circuit
Whether 100 reach the state of impedance matching with equivalent load circuit 180 between the two.If the comparison result of comparison circuit 160 is aobvious
Show that the impedance of both transmission line drive circuit 100 and equivalent load circuit 180 does not match, then adjustment circuit 170 can pass through tune
The mode of at least one of resistance value of whole first adjustable resistance 132 and the second adjustable resistance 134, Lai Jiaozheng transmission line drive
The output impedance of dynamic circuit 100.In this way, just adapting to property, effectively correct transmission line drive circuit 100 and equivalent load
Impedance mismatch situation between circuit 180, so that both transmission line drive circuit 100 and equivalent load circuit 180 reach resistance
Resist matched state.
Aforementioned adjustment circuit 170 adjusts the first adjustable resistance 132 and second according to the comparison result of comparison circuit 160 can
The running for adjusting at least one of resistance value of resistance 134, also can reduce or eliminate the first signal node 122 and second signal
The asymmetric situation of output electric current between node 124, therefore the problem of electromagnetic interference and reflection loss can be effectively reduced.
In addition, the framework of aforementioned transmission line drive circuit 100 is suitable for the framework of various circuit of output terminal, therefore it applies model
It encloses quite extensively.
Some vocabulary is used in the application documents of present patent application to censure specific element.However, affiliated technology
Technical staff in field is, it is to be appreciated that same element may be called with different nouns.Specification and claim are simultaneously
Not in such a way that the difference of title is as element is distinguished, but carry out the benchmark as differentiation with the difference of element functionally.?
"comprising" mentioned by specification and claim is open term, therefore should be construed to " including but not limited to ".Separately
Outside, " coupling " is herein comprising any direct and indirect connection means.Therefore, if it is described herein that first element is coupled to second yuan
Part, then representing first element can be directly connected by being electrically connected or being wirelessly transferred, and the signals connection type such as optical delivery
In second element, or by other elements or connection means, electrical property or signal are connected to the second element indirectly.
It is used herein " and/or " describing mode, any group comprising one of cited or multiple projects
It closes.In addition, unless specified in the instructions, otherwise the term of any singular lattice all includes the connotation of multiple grid simultaneously.
The foregoing is merely a prefered embodiment of the invention, all equivalent changes and modifications done according to the claims in the present invention, all
It should belong to the scope of the present invention.
Claims (8)
1. a kind of transmission line drive circuit for adaptive correction impedance matching, includes:
There is one transmission line driving amplifier one first transmission end for providing a pair of differential formula transmission signal to pass with one second
Defeated end；
One first signal node, for coupling one first load end signal node of an equivalent load circuit；
One second signal node, for coupling one second load end signal node of the equivalent load circuit；
One first adjustable resistance a, wherein first end of first adjustable resistance is coupled to the first of transmission line driving amplifier
Transmission end, and a second end of first adjustable resistance is coupled to the first signal node；
One second adjustable resistance a, wherein first end of second adjustable resistance is coupled to the second of transmission line driving amplifier
Transmission end, and a second end of second adjustable resistance is coupled to second signal node；
One internal node；
One first divider resistance, wherein a first end of first divider resistance be coupled to first adjustable resistance and this first
On signal path between signal node, and a second end of first divider resistance is coupled to the internal node；
One second divider resistance, wherein a first end of second divider resistance be coupled to second adjustable resistance and this second
On signal path between signal node, and a second end of second divider resistance is coupled to the internal node；
One comparison circuit is coupled to the internal node, is arranged to compare the partial pressure on a reference voltage and the internal node, with
Generate a comparison signal；And
One adjustment circuit is coupled to first adjustable resistance, second adjustable resistance and the comparison circuit, and being arranged to foundation should
Comparison signal adjusts at least one of resistance value of first adjustable resistance He second adjustable resistance, so that the transmission line
Driving circuit and the equivalent load circuit reach the state of impedance matching.
2. transmission line drive circuit as claimed in claim 1, wherein the reference voltage is one that the transmission line driving amplifier provides
Common-mode voltage.
3. transmission line drive circuit as claimed in claim 2, wherein when the comparison signal vibrates between positive and negative configuration, the adjustment
Circuit can adjust at least one of resistance value of first adjustable resistance He second adjustable resistance, so that this compares letter
Number stablize in one of positive configuration and negative configuration.
4. transmission line drive circuit as claimed in claim 3, wherein the adjustment circuit is arranged to gradually adjust in multiple calibration cycles
The resistance value of whole first adjustable resistance or the resistance value of second adjustable resistance, stablize in positive configuration until the comparison signal and
Until one of negative configuration.
5. transmission line drive circuit as claimed in claim 3, wherein the adjustment circuit is arranged in a single calibration cycle directly
The resistance value of first adjustable resistance is cut to a first object value, or directly by the resistance value tune of second adjustable resistance
It is raised to one second target value, so that the comparison signal is stablized in one of positive configuration and negative configuration.
6. transmission line drive circuit as claimed in claim 1, wherein first signal node and the second signal node are a media
A pair of differential formula signal node in relevant interface.
7. transmission line drive circuit as claimed in claim 1, wherein first signal node and the second signal node are a bridgings
A pair of differential formula signal node in formula medium dependent interfaces.
8. transmission line drive circuit as claimed in claim 1, wherein the comparison circuit is a hysteresis comparator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410527907.3A CN105577134B (en) | 2014-10-09 | 2014-10-09 | Transmission line drive circuit for adaptive correction impedance matching |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410527907.3A CN105577134B (en) | 2014-10-09 | 2014-10-09 | Transmission line drive circuit for adaptive correction impedance matching |
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| Publication Number | Publication Date |
|---|---|
| CN105577134A CN105577134A (en) | 2016-05-11 |
| CN105577134B true CN105577134B (en) | 2019-05-07 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410527907.3A Active CN105577134B (en) | 2014-10-09 | 2014-10-09 | Transmission line drive circuit for adaptive correction impedance matching |
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Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US9893718B1 (en) * | 2016-10-17 | 2018-02-13 | Globalfoundries Inc. | Transmission driver impedance calibration circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1051426A (en) * | 1989-11-01 | 1991-05-15 | 约翰弗兰克制造公司 | Has the metering circuit of improving the ratio scale that suppresses noise |
| CN1316130A (en) * | 1999-06-28 | 2001-10-03 | 皇家菲利浦电子有限公司 | Muting circuit having controllable impedance means for soft muting |
| CN1368791A (en) * | 2001-02-10 | 2002-09-11 | 深圳赛意法微电子有限公司 | Turn-off noise suppressing circuit and method for audio amplifier |
| CN102468840A (en) * | 2010-11-04 | 2012-05-23 | 联发科技股份有限公司 | Differential driver with calibration circuit and related calibration method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030085737A1 (en) * | 2001-11-08 | 2003-05-08 | Tinsley Steven J. | Innovative high speed LVDS driver circuit |
| US7965121B2 (en) * | 2008-01-03 | 2011-06-21 | Mediatek Inc. | Multifunctional output drivers and multifunctional transmitters using the same |
-
2014
- 2014-10-09 CN CN201410527907.3A patent/CN105577134B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1051426A (en) * | 1989-11-01 | 1991-05-15 | 约翰弗兰克制造公司 | Has the metering circuit of improving the ratio scale that suppresses noise |
| CN1316130A (en) * | 1999-06-28 | 2001-10-03 | 皇家菲利浦电子有限公司 | Muting circuit having controllable impedance means for soft muting |
| CN1368791A (en) * | 2001-02-10 | 2002-09-11 | 深圳赛意法微电子有限公司 | Turn-off noise suppressing circuit and method for audio amplifier |
| CN102468840A (en) * | 2010-11-04 | 2012-05-23 | 联发科技股份有限公司 | Differential driver with calibration circuit and related calibration method |
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| CN105577134A (en) | 2016-05-11 |
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