CN1661910A - Gain control circuit and relevant amplifier - Google Patents
Gain control circuit and relevant amplifier Download PDFInfo
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- CN1661910A CN1661910A CN 200410006604 CN200410006604A CN1661910A CN 1661910 A CN1661910 A CN 1661910A CN 200410006604 CN200410006604 CN 200410006604 CN 200410006604 A CN200410006604 A CN 200410006604A CN 1661910 A CN1661910 A CN 1661910A
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- 238000010586 diagram Methods 0.000 description 3
- 101150064138 MAP1 gene Proteins 0.000 description 1
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- 230000007935 neutral effect Effects 0.000 description 1
- 230000001915 proofreading effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000002277 temperature effect Effects 0.000 description 1
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Abstract
The gain amplifier includes following parts: a gain control circuit generates a gain control voltage based on a control voltage; variable gain amplifying unit is connected to the gain control circuit; and an input voltage adjusts an output signal outputted to a load based on gain control voltage. The said gain control circuit includes following parts: level adjustment possessing a fixing current source generates a first voltage based on control voltage; at least one first temperature compensation unit possessing first temp control (PTAT) current source generates a second voltage based on current operation temp; and a voltage conversion unit generates the said gain control voltage based on first and second voltages.
Description
Technical field
The present invention is relevant for a kind of control circuit, and relevant especially a kind of gain control circuit reaches relevant gain controller.
Background technology
As shown in fig. 1, be traditional variable gain amplifier (variable gainamplifier) 50, wherein a gain-controlled voltage V
CTRLIn order to control by transistor T
9, T
10The differential current ratio that is constituted to (differential pair), and then adjust the electric current I of the load LD that flows through
LSize.In addition, electric current I
LCan be tried to achieve by following equation one, wherein gm is the gain size of variable gain amplifier 50, V
RFBe an input voltage, V
TIt is a parameter.
I
rf＝gm×V
RF
Fig. 2, Fig. 3 represent in the amplifier 50, the gain-controlled voltage V of a linearity
CTRLAnd the relation between the gain.As shown in Figure 2, in this scope of 0dB-20dB, gain-controlled voltage V
CTRLAnd the relation curve RC between the gain is not linear.In order to obtain this relation curve RC, need a gain control circuit, in order to produce the gain-controlled voltage V of a correspondence according to an external control voltage
CTRL, and be a logarithm linear relationship (log-linearrelationship) between the gain of this outside control voltage and amplifier 50.
In addition, shown in equation one, electric current I
LWith V parameter
TRelevant, and
Wherein k is that ripple is grown graceful constant, and T is an absolute temperature, and q is a quantities of charge.Therefore, when temperature change, the current switching characteristic will change.
Summary of the invention
In view of this, primary and foremost purpose of the present invention is to cause the external control voltage of variable gain amplifier and gain to present a logarithm linear relationship (log-linear relationship).
Another object of the present invention is subjected to the change of temperature effect in order to the gain controlling of proofreading and correct variable gain amplifier.
For reaching described purpose, the invention provides a kind of gain control circuit, comprise a level adjustment unit, have a fixed current source, produce one first voltage according to a control voltage; At least one first temperature compensation unit has one first temperature control (Proportional To Absolute Temperature; PTAT) current source in order to according to present working temperature, produces one second voltage; And a voltage conversion unit, in order to first, second voltage, produce a gain-controlled voltage.
According to described purpose, the present invention more provides a gain amplifier, comprise a foregoing gain control circuit, in order to control voltage according to one, produce a gain-controlled voltage, and a variable gain amplifying unit, a gain control circuit and an input voltage connected, according to gain-controlled voltage, adjust the output signal that exports load to.
For described and other purposes of the present invention, feature and advantage can be become apparent, a preferred embodiment cited below particularly, and cooperate appended diagram, be described in detail below:
Description of drawings
Fig. 1 shows a traditional variable gain amplifier:
Relation between the amplifier neutral line gain-controlled voltage of Fig. 2, Fig. 3 displayed map 1 and the gain.
Fig. 4 is the schematic diagram of variable gain amplifier of the present invention.
Fig. 5 shows among the present invention, the relation curve between control voltage and gain-controlled voltage, and the relation curve between control voltage and its gain.
Fig. 6 is first embodiment of gain control circuit of the present invention
Fig. 7 is second embodiment of gain control circuit of the present invention.
Fig. 8 is the 3rd embodiment of gain control circuit of the present invention.
Symbol description
50: variable gain amplifier; V
CTRL: gain-controlled voltage;
R
0: resistance; LD: load;
T
9-T
11: transistor; V
RF: input voltage;
I
L, I
Ac: electric current.
100,100a, 100b, 100c: gain control circuit;
200: the variable gain amplifying unit; 300: variable gain amplifier;
10: the level adjustment unit; 12: bleeder circuit;
20: temperature compensation unit; 30: voltage conversion unit;
V
AGC: control voltage; V
CTRL: gain-controlled voltage;
V
RF: input voltage; LD: load;
T
1-T
11: transistor; I
Tc: the fixed current source;
I
E1, I
E7: current source; V
0: branch pressure voltage;
R
E1, R
E2: resistance element; V
Dd: supply voltage;
V
1: first voltage; V
2: second voltage;
V
3: tertiary voltage; V
4: the 4th voltage;
N
1-N
6: node; Gm1-Gm3: trsanscondutor;
R
0-R
7, R
Tc, R
Ptat: resistance;
I
L, I
Re1, I
Re2, I
1-I
6: electric current;
I
Ptat, I
Ptat1, I
Ptat2, I
Ptat3: temperature Control current source
Embodiment
Fig. 4 is the schematic diagram of variable gain amplifier of the present invention.As shown in Figure 4, variable gain amplifier 300 of the present invention comprises a gain control circuit 100 and a variable gain amplifying unit 200.Gain control circuit 100 is according to a control voltage V
AGC, produce a gain-controlled voltage V
CTRLVariable gain amplifying unit 200 connects a gain control circuit 100 and an input voltage V
RF, according to gain-controlled voltage V
CTRL, adjust and export the output signal of load to, as the electric current I of the load LD that flows through
LFor instance, gain-controlled voltage V
CTRLIn order to control by transistor T
9, T
10The differential current ratio that is constituted to (differentialpair), and then adjust the electric current I of the load LD that flows through
LSize is promptly adjusted the gain size of variable amplifying unit 200.
Fig. 5 is in order to represent in the variable gain amplifier 300 of the present invention control voltage V
AGCWith gain-controlled voltage V
CTRLBetween relation curve RC
1, and control voltage V
AGCAnd the relation curve RC between the gain of amplifying unit 200 (gain)
2In the present invention, input to the control voltage V of gain control circuit 100
AGCAnd can present a logarithm linear relationship (log-linearrelationship) between the gain (gain) of gain amplifying unit 200, make gain-controlled voltage V
CTRLWith the relation of gain (gain) of gain amplifying unit 200, can be as shown in the curve RC among Fig. 2.
In addition, constant in order to keep gain control features, when temperature change, gain-controlled voltage V
CTRLAlso will be with the temperature adjustment.Therefore, use two kinds of different current sources in the present invention, a kind of is the fixed current source, can be with temperature change, and another kind is temperature control (PTAT) current source, can change with temperature.Therefore, when temperature rises, gain-controlled voltage V
CTRLAlso with change is big, in order to compensation V
TThe influence that parameter causes, constant to keep gain control features.
First embodiment
Fig. 6 is first embodiment of gain control circuit 100 of the present invention.As shown in Figure 6, gain control circuit 100a comprises a level adjustment unit 10, has a fixed current source I
Tc, according to control voltage V
AGCProduce one first voltage V
1One temperature compensation unit 20 has a temperature Control current source I
Ptat,, produce one second voltage V in order to according to present working temperature
2And a voltage conversion unit 30, in order to according to first, second voltage V
1, V
2, produce gain-controlled voltage V
CTRL
Therefore, when temperature rises, temperature Control current source I
PataCan change the second voltage V
2Size, to improve gain-controlled voltage V
CTRL,, use that to keep gain control features constant in order to the influence that compensation VT parameter causes.
Second embodiment
Fig. 7 is second embodiment of gain control circuit 100 of the present invention.As shown in Figure 7, gain control circuit 100b comprises a level adjustment unit 10, has a fixed current source I
Tc, according to control voltage V
AGCProduce one first voltage V
1One temperature compensation unit 20 has a temperature Control current source I
Ptat,, produce one second voltage V in order to according to present working temperature
2And a voltage conversion unit 30, in order to according to first, second voltage V
1, V
2, produce gain-controlled voltage V
CTRLIn present embodiment, level adjustment unit 10 is identical in first embodiment with temperature compensation unit 20, is not repeated at this.
In present embodiment, voltage conversion unit 30 comprises three trsanscondutor Gm
1, Gm
2And Gm
3, and two resistance element R
E1, R
E2, three trsanscondutor Gm wherein
1, Gm
2And Gm
3Has different threshold voltages.Trsanscondutor Gm
1-Gm
3In order to will be from the first voltage V of level adjustment unit 10
1Reach the second voltage V from temperature compensation unit 20
2, convert the one first to the 6th electric current I to
1-I
6Resistance element R
E1, R
E2Can be according to first to second electric current I
1-I
6, produce voltage drop, node N
3With node N
4Between voltage difference, as gain-controlled voltage V
CTRL, export variable gain amplifying unit 200 to.
Trsanscondutor Gm
1Comprise one by transistor T
3, T
4Become the differential of structure to (differentialpair), resistance R
3, R
6And two current source I
E1, I
E2Transistor T
3, T
4Control end connect first, second voltage V respectively
1, V
2, differential right current ratio can be according to first, second voltage V
1, V
2And change, flow to resistance element R with adjustment
E1, R
E2Electric current I
1, I
2Trsanscondutor Gm
2Comprise one by transistor T
5, T
6Become the differential of structure to (differential pair), resistance R
4, R
7And two current source I
E3, I
E4Transistor T
5, T
6Control end connect first, second voltage V respectively
1, V
2, and differential right current ratio can be according to first, second voltage V
1, V
2And change, flow to resistance element R with adjustment
E1, R
E2Electric current I
3, I
4Trsanscondutor Gm
3Comprise one by transistor T
7, T
8Become the differential of structure to (differentialpair), resistance R
5, R
8And two current source I
E5, I
E6Transistor T
7, T
8Control end connect first, second voltage V respectively
1, V
2, and differential right current ratio can be according to first, second voltage V
1, V
2And change, flow to resistance element R with adjustment
E1, R
E2Electric current I
5, I
6
In present embodiment, because resistance R
6, R
7Difference, trsanscondutor Gm
1, Gm
2And Gm
3Can not have one first, second, third threshold voltage.For instance, as first, second voltage V
1, V
2Voltage difference when surpassing one first predetermined level, have only trsanscondutor Gm
1Can be according to first, second voltage V
1, V
2, produce first, second electric current I
1, I
2, and trsanscondutor Gm
2, Gm
3And inoperative, this moment electric current I
Re1Can equal first electric current I
1, and this moment electric current I
Re2Can equal second electric current I
2
If first, second voltage V
1, V
2Voltage difference when surpassing one second predetermined level, have only trsanscondutor Gm
1, Gm
2Can work, with according to first, second voltage V
1, V
2, produce first, second, third, fourth electric current I
1, I
2, I
3And I
4, and trsanscondutor Gm
3And inoperative, this moment electric current I
Re1Can equal first electric current I
1With the 3rd electric current I
3Summation, and this moment electric current I
Re2Can equal second electric current I
2With the 4th electric current I
4Summation.
If first, second voltage V
1, V
2Voltage difference when surpassing one the 3rd predetermined level, trsanscondutor Gm
1, Gm
2, Gm
3All can work, with according to first, second voltage V
1, V
2, produce the first, second, third, fourth, the 5th, the 6th electric current I
1, I
2, I
3, I
4, I
5And I
6, this moment electric current I
Re1Can equal first electric current I
1, the 3rd electric current I
3With the 5th electric current I
5Summation, and this moment electric current I
Re2Can equal second electric current I
2, the 4th electric current I
4With the 6th electric current I
6Summation.
As shown in Figure 3, in that low gain is interval when changing, 0-5dB for example, pairing gain-controlled voltage V
CTRLNeed bigger variation slope, and when between high gain region, changing, 10-20dB for example, pairing gain-controlled voltage V
CTRLNeed less variation slope.Therefore, the present invention uses a plurality of trsanscondutors with different threshold voltages, little by little starts when gain changes, and makes to control voltage V
AGCWith corresponding gain-controlled voltage V
CTRLBetween the slope steepening, with retentive control voltage V
AGCAnd the relation of logarithm-linearity (log-linear) between gain.
In addition, when temperature rises, temperature Control current source I
PataCan change the second voltage V
2Size, to improve gain-controlled voltage V
CTRL,, constant to keep gain control features in order to the influence that compensation VT parameter causes.
Therefore, in variable gain amplifier of the present invention, gain-controlled voltage V
CTRLThe relation of gain (gain) with the gain amplifying unit can obtain the relation as the curve RC among Fig. 2, and gain control features temperature influence not.
The 3rd embodiment
Fig. 8 is the 3rd embodiment of gain control circuit 100 of the present invention.As shown in Figure 7, gain control circuit 100c comprises a level adjustment unit 10, three temperature compensation unit 20-1-20-3 and voltage conversion units 30.
In present embodiment, voltage conversion unit 30 comprises three trsanscondutor Gm
1, Gm
2And Gm
3, and two resistance element R
E1, R
E2, wherein three trsanscondutor Gm1, Gm2 and Gm
3Has different threshold voltages, wherein trsanscondutor Gm
1-Gm
3Circuit structure and Fig. 7 in identical.
Trsanscondutor Gm
1In order to will be from the first voltage V of level adjustment unit 10
1Reach the second voltage V from temperature compensation unit 20-1
2, convert one first to second electric current I to
1, I
2Trsanscondutor Gm
2In order to will be from the first voltage V of level adjustment unit 10
1Reach tertiary voltage V from temperature compensation unit 20-2
3, convert the one the 3rd to the 4th electric current I to
3, I
4Trsanscondutor Gm
3In order to will be from the first voltage V of level adjustment unit 10
1And from the 4th voltage V of temperature compensation unit 20-3
4, convert the one the 5th to the 6th electric current I to
5, I
6In other words, trsanscondutor Gm
1Can be according to first, second voltage V
1, V
2Adjustment flow to resistance element R
E1, R
E2Electric current I
1, I
2Trsanscondutor Gm
2Can be according to first, tertiary voltage V
1, V
3Adjustment flow to resistance element R
E1, R
E2Electric current I
3, I
4Trsanscondutor Gm
3Can be according to the first, the 4th voltage V
1, V
4Adjustment flow to resistance element R
E1, R
E2Electric current I
5, I
6
For instance, trsanscondutor Gm
1, Gm
2, Gm
3With according to first to fourth voltage, under corresponding threshold voltage, produce the first, second, third, fourth, the 5th, the 6th electric current I
1, I
2, I
3, I
4, I
5And I
6Electric current I
Re1Can equal first electric current I
1, the 3rd electric current I
3With the 5th electric current I
5Summation, and electric current I
Re2Can equal second electric current I
2, the 4th electric current I
4With the 6th electric current I
6Summation.Resistance element R
E1, R
E2Can be according to electric current I
Re1, I
Re2, produce voltage drop, node N
5With node N
6Between voltage difference, as gain-controlled voltage V
CTRL, export variable gain amplifying unit 200 to.
As shown in Figure 3, in that low gain is interval when changing, 0-5dB for example, pairing gain-controlled voltage V
CTRLNeed bigger variation slope, and when between high gain region, changing, 10-20dB for example, pairing gain-controlled voltage V
CTRLNeed less variation slope.Therefore, the present invention uses a plurality of trsanscondutors with different threshold voltages, little by little starts when gain changes, and makes to control voltage V
AGCWith corresponding gain-controlled voltage V
CTRLBetween the slope steepening, with retentive control voltage V
AGCAnd the relation of logarithm-linearity (log-linear) between gain.
In addition, when temperature rises, temperature Control current source I
Pata1, I
Pata2, I
Pata3Can change respectively second, third, the 4th voltage V
2, V
3, V
4Size, to improve gain-controlled voltage V
CTRL,, use that to keep gain control features constant in order to the influence that compensation VT parameter causes.
Therefore, in variable gain amplifier of the present invention, gain-controlled voltage V
CTRLThe relation of gain (gain) with the gain amplifying unit can obtain the relation as the curve RC among Fig. 2, and gain control features temperature influence not.
In sum; though the present invention with a preferred embodiment openly as above; right its is not in order to limit the present invention; any those skilled in the art; under the situation that does not break away from the spirit and scope of the present invention; can carry out various changes and modification, so protection scope of the present invention is as the criterion when looking the claim restricted portion that is proposed.
Claims (16)
1. gain control circuit comprises:
One level adjustment unit has a fixed current source, produces one first voltage according to a control voltage;
At least one first temperature compensation unit has one first temperature Control current source, in order to according to present working temperature, produces one second voltage; And
One voltage conversion unit in order to according to described first, second voltage, produces a gain-controlled voltage.
2. gain control circuit as claimed in claim 1, wherein said voltage conversion unit comprises:
One trsanscondutor in order to described first, second voltage, converts first, second electric current to; And
One first, second resistance element in order to described first, second electric current, converts described gain-controlled voltage to.
3. gain control circuit as claimed in claim 2, wherein said level adjustment unit also comprises:
One bleeder circuit connects described control voltage, in order to produce one first dividing potential drop; And
One the first transistor, have a control end and connect described first dividing potential drop, one first end connects an earthed voltage, and one second end connects a first node via one first resistance, and wherein said fixed current source is connected between a supply voltage and the described first node.
4. gain control circuit as claimed in claim 3, wherein said temperature compensation unit also comprises:
One transistor seconds, have one first end and be connected to a Section Point via one second resistance, and one second end and a control end be connected to described earthed voltage, the wherein said first temperature Control current source is connected between described supply voltage and the described Section Point.
5. gain control circuit as claimed in claim 4, wherein said trsanscondutor comprise that one is differential right, have differential input terminal, are connected respectively to described first, second node, and the voltage on wherein said first, second node is as described first, second voltage.
6. gain control circuit as claimed in claim 1, wherein said voltage conversion unit comprises:
One first trsanscondutor has a first threshold voltage, during greater than described first threshold voltage, produces first, second electric current in the voltage difference of described first, second voltage;
One second trsanscondutor has one second threshold voltage, during greater than described second threshold voltage, produces the one the 3rd, the 4th electric current in the voltage difference of described first, second voltage; And
One first, second resistance element in order to according to the electric current that described first, second trsanscondutor produced, produces described gain-controlled voltage.
7. gain control circuit as claimed in claim 1, also comprise one second temperature compensation unit, has one second temperature Control current source, in order to according to described present working temperature, produce a tertiary voltage, wherein said voltage conversion unit produces described gain-controlled voltage according to described first, second, third voltage.
8. gain control circuit as claimed in claim 7, wherein said voltage conversion unit comprises:
One first trsanscondutor connects described first temperature compensation unit, has a first threshold voltage, during greater than described first threshold voltage, produces first, second electric current in the voltage difference of described first, second voltage;
One second trsanscondutor connects described second temperature compensation unit, has one second threshold voltage, during greater than described second threshold voltage, produces the one the 3rd, the 4th electric current in the voltage difference of described first, tertiary voltage; And
One first, second resistance element connects described first, second trsanscondutor, in order to according to the electric current that described first, second trsanscondutor produced, produces described gain-controlled voltage.
9. gain amplifier comprises:
One gain control circuit in order to according to a control voltage, produces a gain-controlled voltage, comprising:
One level adjustment unit has a fixed current source, produces one first voltage according to described control voltage;
At least one first temperature compensation unit has one first temperature Control current source, in order to according to present working temperature, produces one second voltage; And
One voltage conversion unit in order to according to described first, second voltage, produces described gain-controlled voltage;
And
One variable gain amplifying unit connects a described gain control circuit and an input voltage, according to described gain-controlled voltage, adjusts the output signal that exports load to.
10. gain amplifier as claimed in claim 9, wherein said voltage conversion unit comprises:
One trsanscondutor in order to described first, second voltage, converts first, second electric current to; And
One first, second resistance element in order to described first, second electric current, converts described gain-controlled voltage to.
11. gain amplifier as claimed in claim 10, wherein said level adjustment unit also comprises:
One bleeder circuit connects described control voltage, in order to produce one first dividing potential drop; And
One the first transistor, have a control end and connect described first dividing potential drop, one second end connects a first node via one first resistance, and one first end connects an earthed voltage, and wherein said fixed current source is connected between a supply voltage and the described first node.
12. gain amplifier as claimed in claim 11, wherein said temperature compensation unit also comprises:
One transistor seconds, have one first end and be connected to a Section Point via one second resistance, and one second end and a control end be connected to described earthed voltage, the wherein said first temperature Control current source is connected between described supply voltage and the described Section Point.
13. gain amplifier as claimed in claim 12, wherein said trsanscondutor comprise that one is differential right, have differential input terminal, are connected respectively to described first, second node, the voltage on wherein said first, second node is as described first, second voltage.
14. gain amplifier as claimed in claim 9, wherein said voltage conversion unit comprises:
One first trsanscondutor has a first threshold voltage, during greater than described first threshold voltage, produces first, second electric current in the voltage difference of described first, second voltage;
One second trsanscondutor has one second threshold voltage, during greater than described second threshold voltage, produces the one the 3rd, the 4th electric current in the voltage difference of described first, second voltage; And
One first, second resistance element in order to according to described first, second, third, fourth electric current that described first, second trsanscondutor produced, produces described gain-controlled voltage.
15. gain amplifier as claimed in claim 9, also comprise one second temperature compensation unit, has one second temperature Control current source, in order to according to described present working temperature, produce a tertiary voltage, wherein said voltage conversion unit produces described gain-controlled voltage according to described first, second, third voltage.
16. gain amplifier as claimed in claim 15, wherein said voltage conversion unit comprises:
One first trsanscondutor connects described first temperature compensation unit, has a first threshold voltage, during greater than described first threshold voltage, produces first, second electric current in the voltage difference of described first, second voltage;
One second trsanscondutor connects described second temperature compensation unit, has one second threshold voltage, during greater than described second threshold voltage, produces the one the 3rd, the 4th electric current in the voltage difference of described first, tertiary voltage; And
One first, second resistance element connects described first, second trsanscondutor, in order to according to described first, second, third, fourth electric current that described first, second trsanscondutor produced, produces described gain-controlled voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100066043A CN100486112C (en) | 2004-02-24 | 2004-02-24 | Gain control circuit and relevant gain amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100066043A CN100486112C (en) | 2004-02-24 | 2004-02-24 | Gain control circuit and relevant gain amplifier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1661910A true CN1661910A (en) | 2005-08-31 |
| CN100486112C CN100486112C (en) | 2009-05-06 |
Family
ID=35011035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100066043A Expired - Lifetime CN100486112C (en) | 2004-02-24 | 2004-02-24 | Gain control circuit and relevant gain amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100486112C (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101741319A (en) * | 2008-11-17 | 2010-06-16 | 立锜科技股份有限公司 | Heat regulating device and method for D-type audio amplifier and D-type audio amplifier with heat regulation |
| CN101013911B (en) * | 2007-02-13 | 2011-06-01 | 展讯通信（上海）有限公司 | Control circuit of radio-frequency variable gain amplifier and gain control method |
| CN101697479B (en) * | 2009-10-30 | 2012-02-08 | 凌阳科技股份有限公司 | Adjustable grain low noise amplifier |
| CN102843101A (en) * | 2011-06-20 | 2012-12-26 | 苏州科山微电子科技有限公司 | Variable gain low-noise amplifier |
| CN108075739A (en) * | 2016-11-17 | 2018-05-25 | 联发科技股份有限公司 | Variable gain amplifier |
| WO2023087589A1 (en) * | 2021-11-17 | 2023-05-25 | 深圳市中兴微电子技术有限公司 | Variable gain amplifier and transmitting apparatus |
-
2004
- 2004-02-24 CN CNB2004100066043A patent/CN100486112C/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101013911B (en) * | 2007-02-13 | 2011-06-01 | 展讯通信（上海）有限公司 | Control circuit of radio-frequency variable gain amplifier and gain control method |
| CN101741319A (en) * | 2008-11-17 | 2010-06-16 | 立锜科技股份有限公司 | Heat regulating device and method for D-type audio amplifier and D-type audio amplifier with heat regulation |
| CN101741319B (en) * | 2008-11-17 | 2013-09-11 | 立锜科技股份有限公司 | Heat regulating device and method for D-type audio amplifier and D-type audio amplifier with heat regulation |
| CN101697479B (en) * | 2009-10-30 | 2012-02-08 | 凌阳科技股份有限公司 | Adjustable grain low noise amplifier |
| CN102843101A (en) * | 2011-06-20 | 2012-12-26 | 苏州科山微电子科技有限公司 | Variable gain low-noise amplifier |
| CN102843101B (en) * | 2011-06-20 | 2015-06-10 | 苏州科山微电子科技有限公司 | Variable gain low-noise amplifier |
| CN108075739A (en) * | 2016-11-17 | 2018-05-25 | 联发科技股份有限公司 | Variable gain amplifier |
| WO2023087589A1 (en) * | 2021-11-17 | 2023-05-25 | 深圳市中兴微电子技术有限公司 | Variable gain amplifier and transmitting apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100486112C (en) | 2009-05-06 |
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