CN102270972A - Variable-gain amplifier - Google Patents

Variable-gain amplifier Download PDF

Info

Publication number
CN102270972A
CN102270972A CN2011100971064A CN201110097106A CN102270972A CN 102270972 A CN102270972 A CN 102270972A CN 2011100971064 A CN2011100971064 A CN 2011100971064A CN 201110097106 A CN201110097106 A CN 201110097106A CN 102270972 A CN102270972 A CN 102270972A
Authority
CN
China
Prior art keywords
resistance
operational amplifier
gain
circuit
amplifier
Prior art date
Application number
CN2011100971064A
Other languages
Chinese (zh)
Inventor
闫涛涛
沈晓斌
周健军
Original Assignee
上海信朴臻微电子有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海信朴臻微电子有限公司 filed Critical 上海信朴臻微电子有限公司
Priority to CN2011100971064A priority Critical patent/CN102270972A/en
Publication of CN102270972A publication Critical patent/CN102270972A/en

Links

Abstract

The invention provides a variable-gain amplifier which comprises an operational amplifier, at least one series resistance circuit, a switching circuit and a decoding circuit, wherein one end of the series resistance circuit serves as a signal input terminal and the other end thereof is connected with an output terminal of the operational amplifier, and the series resistance circuit is formed by series connection of a plurality of resistors; the switching circuit is connected with a plurality of nodes of each series resistance circuit and one input terminal of the operational amplifier and controls the on/off of the nodes of each series resistance circuit and the one input terminal of the operational amplifier, so that a part of resistors in each series resistance circuit serve as input resistors of the operational amplifier and the rest resistors serve as feedback resistors of the operational amplifier; the decoding circuit is used for decoding an input control signal to output on/off signals for controlling the on/off of a plurality of controlled switches. The variable-gain amplifier provided by the invention has the following advantages: the switching circuit is isolated from signal channels, so as to eliminate the impact of on-resistance of the individual switches on the input impedance and feedback impedance of the operational amplifier and increase the gain linearity.

Description

Gain variable amplifier

Technical field

The present invention relates to circuit field, particularly a kind of gain variable amplifier.

Background technology

In the Modern wireless communication technology, because the uncertainty of received signal power, automatic gain control becomes an important module in the communication system, and gain variable amplifier is the core in the automatic gain control loop.Automatic gain control loop is by regulating the gain control signal of gain variable amplifier, and the amplitude stability that makes output signal is not subjected to the influence of input signal amplitude in a scope, alleviate the difficulty of subsequent conditioning circuit processing signals.The linearity, low noise, low-power consumption, high bandwidth, on dB and gain control signal linear etc., all be basic demand to gain variable amplifier.

Below be two kinds of gain variable amplifier structures relatively more commonly used at present:

First kind: see also Fig. 1, it is based on the schematic diagram of the gain variable amplifier of resistance and operational amplifier.This gain variable amplifier is realized gain controlling by the resistance of two electric resistance arrays of change feedback network, and its gain equals the ratio of feedback resistance array and input resistance array, that is:

G = R f R s

Wherein, R fBe the resistance of feedback resistance array, R sBe the resistance of input resistance array, such gain variable amplifier belongs to closed-loop structure, so its linearity is higher relatively, but because the variation of gain is to realize by the switch that control is connected with resistance.In the CMOS integrated circuit, each switch adopts MOS transistor, and the conducting resistance of MOS transistor can change with drain-source voltage, thereby causes the linearity of whole gain variable amplifier to worsen.

In addition, another shortcoming of the gain variable amplifier of this kind structure is exactly that switch and resistance are in series, therefore, the resistance of the resistance of feedback resistance array and input resistance array all will comprise the conducting resistance of corresponding M OS transistor switch interior, and the conducting resistance of mos transistor switch is difficult to measuring and calculating, and with temperature, technology, change in voltage and changing.In the CMOS integrated circuit, be difficult to realize the coupling of switch and resistance, thereby cause the inaccurate of gain controlling, and then influence the stabilization time of whole automatic gain control loop.

Second kind: in Chinese patent CN101373957A, described a kind of Method and circuits of digital gain control.The variable-resistance resistance of coming the ride gain variable amplifier by N bit binary number gain controlling sign indicating number, carry out the gain-adjusted of variable gain amplifier thus, its variable resistor adopts mos transistor array, utilize the conducting resistance between transistorized source-drain electrode and the relation of grid voltage to control variable resistance, produce each transistorized grid voltage of mos transistor array by gain control module according to N bit binary number gain controlling sign indicating number, thereby realize the gain controlling of degree of precision.Yet the gain variable amplifier that uses in this patent is open loop structure, so the linearity of variable gain amplifier is lower.

Because conducting resistance and grid voltage between transistorized source-drain electrode are not complete linear relationship yet, though attainable gain adjustment step interval is less, step-length is not a constant, and deviation is bigger, can't realize linear relationship more accurately on dB on the other hand.

Summary of the invention

The object of the present invention is to provide a kind of gain variable amplifier, to reduce the influence of switching tube to gain.

Reach other purposes in order to achieve the above object, gain variable amplifier provided by the invention comprises: operational amplifier; The series resistance circuit that at least one 1 ends are connected described operational amplifier output terminal and are in series by a plurality of resistance as signal incoming end, the other end; With a plurality of nodes of each bar series resistance circuit and a switching circuit that input is connected of described operational amplifier, it comprises a plurality of controlled switchs, be used to control the break-make of an input of a plurality of nodes of each bar series resistance circuit and described operational amplifier, so that the part resistance in each bar series resistance circuit is as the input resistance of described operational amplifier, all the other resistance feedback resistance as described operational amplifier; And decoding circuit, be used for the control signal that inserts is deciphered the switching signal that is used to control described a plurality of controlled switch switchings with output.

In sum, gain variable amplifier of the present invention is by moving away from switching circuit from signal path, can reduce resistance that each switch has thus to the input resistance of operational amplifier and the influence of operational amplifier feedback resistance resistance, with the linearity that improves the operational amplifier gain and the precision of gain-adjusted.

Description of drawings

Fig. 1 is existing gain variable amplifier structural representation based on resistance.

Fig. 2 is the structural representation of gain variable amplifier of the present invention.

Series resistance circuit that Fig. 3 comprises for gain variable amplifier of the present invention and switching circuit schematic diagram.

Fig. 4 is that the gain curve of gain variable amplifier of the present invention and dB linear gain curve ratio are than schematic diagram.

Fig. 5 is that the gain error of gain variable amplifier of the present invention and mathematics error ratio are than schematic diagram.

Fig. 6 is the Cadence Spectre RF AC emulation schematic diagram of gain variable amplifier of the present invention.

Fig. 7 is the THD performance simulation curve synoptic diagram of gain variable amplifier of the present invention.

Fig. 8 is the output harmonic wave component emulation schematic diagram of gain variable amplifier of the present invention.

Embodiment

See also Fig. 2, gain variable amplifier of the present invention comprises: operational amplifier, at least one series resistance circuit, switching circuit and decoding circuit.Wherein, Fig. 2 only illustrates a series resistance circuit, but it should be appreciated by those skilled in the art that in fact, and the quantity of the series resistance circuit that described gain variable amplifier comprises can be for more than 2 or 2.

Described operational amplifier preferably adopts DC current gain to be not less than the amplifier of 60dB, so that improve the precision of gain-adjusted, for example, can adopt the two-stage Miller type operational amplifier in the CMOS technology.

One end of each bar series resistance circuit is connected described operational amplifier output terminal as signal incoming end, the other end, the series resistance circuit that it is in series by a plurality of resistance.For example, series resistance circuit shown in Figure 2 by resistance R 1, R2 ... Rn is in series.Preferably, resistance R 1, R2 ... the resistance of Rn all equates.

A plurality of nodes of described switching circuit and each bar series resistance circuit and an input of described operational amplifier are connected all and are connected, it comprises a plurality of controlled switchs, be used to control the break-make of an input of a plurality of nodes of each bar series resistance circuit and described operational amplifier, so that the part resistance in each bar series resistance circuit constitutes the input resistance of described operational amplifier, the feedback resistance that all the other resistance constitute described operational amplifier.For example, the node 1 of described switching circuit and series resistance circuit, node 2 ... node k connects, be used for Control Node 1, node 2 ... the break-make of node k and operational amplifier end of oppisite phase.For example, when described switching circuit only Control Node 1 be communicated with the input of described operational amplifier, the resistance that is comprised to node 1 by the signal incoming end in the then described series resistance circuit has constituted the input resistance of described operational amplifier, has been made of the feedback resistance of operational amplifier node 1 to the resistance that operational amplifier output terminal comprised.

Preferably, described switching circuit comprises a plurality of first controlled switchs, a plurality of second controlled switch and a plurality of the 3rd controlled switch, wherein, a node, the other end of a series resistance circuit of an end of each first controlled switch connection are connected with an end of one second controlled switch; One end of each second controlled switch connects a plurality of first controlled switchs, the other end connects one the 3rd controlled switch; One end of each the 3rd controlled switch connects the input that a plurality of second controlled switchs, the other end all connect described operational amplifier.More preferred, each first controlled switch, each second controlled switch and each the 3rd controlled switch can all adopt metal-oxide-semiconductor.But those skilled in the art should understand that, each controlled switch is not to exceed with metal-oxide-semiconductor, in fact, other any controlled switchs with controlled end, for example, relay etc., all should be within the scope of the present invention, in addition, each first controlled switch, each second controlled switch reach in each the 3rd controlled switch, the part controlled switch adopts metal-oxide-semiconductor, and other parts adopt relay etc.

For example, as shown in Figure 3, frame of broken lines 11 comprises 4 first controlled switchs, and an end of each controlled switch all is connected a node of described series resistance circuit; Frame of broken lines 21,22 and 23 comprises 4 second controlled switchs separately respectively, and an end of each second controlled switch all connects 4 first controlled switchs; One end of the 3rd controlled switch 31 connects 4 second controlled switchs, the other end concatenation operation amplifier input terminal in the frame of broken lines 21; Equally, an end of the 3rd controlled switch 32 connects 4 second controlled switchs, the other end concatenation operation amplifier input terminal in the frame of broken lines 22; One end of the 3rd controlled switch 33 connects 4 second controlled switchs, the other end concatenation operation amplifier input terminal in the frame of broken lines 23.

Need to prove, the controlled switch that switching circuit comprises and the connected mode of each controlled switch be not with shown in exceed, in fact, switching circuit also can only comprise controlled switch that directly is connected between series resistance circuit node and the operational amplifier input or the like.

Described decoding circuit is used for the control signal that inserts is deciphered the switching signal that is used to control described a plurality of controlled switch switchings with output.

Need to prove, the quantity of the controlled switch that those skilled in the art control according to actual needs and control requirement etc., can adopt hardware description language earlier, Verilog hardware description language for example, be described, by tool software this hardware description language be converted to the real figure circuit more subsequently, obtain described decoding circuit thus, so, no longer the structure of described decoding circuit is described in detail at this.

Preferably, the switching signal of described decoding circuit output only makes a node of series resistance circuit be communicated with the input of described operational amplifier.

Below will analyze the performance of gain variable amplifier of the present invention:

1, supposes that gain variable amplifier of the present invention comprises a series resistance circuit, this series resistance circuit one total 2a identical resistance is in series, a-x is illustrated in the resistance number between the input of signal incoming end and operational amplifier, a+x is illustrated in the resistance number between operational amplifier input and the operational amplifier output terminal, and then the gain of operational amplifier is:

G dB = 20 log ( a + x a - x )

The Taylor expansion of 20lg (a+x) and 20lg (a-x) is as follows:

20 lg ( a + x ) = 20 lg ( a ) + 20 x a ln ( 10 ) - 10 x 2 a 2 ln ( 10 ) + 20 x 3 3 a 3 ln ( 10 ) - 5 x 5 a 4 ln ( 10 ) + 4 x 5 a 5 ln ( 10 ) + L

20 lg ( a - x ) = 20 lg ( a ) - 20 x a ln ( 10 ) - 10 x 2 a 2 ln ( 10 ) - 20 x 3 3 a 3 ln ( 10 ) - 5 x 5 a 4 ln ( 10 ) - 4 x 5 a 5 ln ( 10 ) + L

And then can get: 20 lg ( a + x a - x ) = 40 x a ln ( 10 ) - 40 x 3 3 a 3 ln ( 10 ) - 8 x 5 a 5 ln ( 10 ) + L .

The gain that can be got gain variable amplifier of the present invention by following formula is approximately: Wherein, error function is If a is enough big, for example, be example with the 0.25dB gain, a is about 70, and then error function E rror is very little, can realize high-precision gain variable amplifier.

2, see also Fig. 4 again, it is the comparison that the gain controlling curve of gain variable amplifier of the present invention and ideal linear on dB are controlled curve.As seen from Figure 4, gain variable amplifier of the present invention differs very little with ideal control curve linear on dB at-5.75dB to the 6dB.Worst error is 0.09dB only, is about 9/1000ths.

3, see also Fig. 5 again, it is the comparison schematic diagram of the gain error and the mathematics error of gain variable amplifier of the present invention, and as seen from the figure, the error that gain variable amplifier of the present invention self brings is about 0.01dB, and main error is an error of mathematical model.Because the error of Mathematical Modeling is known, in the exigent application of precision, can by proofread and correct in advance, method such as compensation removes error of mathematical model, thereby further improves the accuracy of gain.

4, see also Fig. 6 again, it carries out the AC simulation result schematic diagram that emulation obtained for adopting Cadence spectre to gain variable amplifier of the present invention, and as seen from the figure, at-5.75dB gain step size basically identical to the 6dB, the AC simulated effect is good.

5, see also Fig. 7 again, it carries out the simulation result schematic diagram of the THD that emulation obtained for adopting Cadence spectre to gain variable amplifier of the present invention, and as seen from the figure, during for 6dB, input signal is the 1MHz sine wave in gain, and power is 0dBm.THD is 2.248 * 10 -3%, functional.

6, see also Fig. 8 again, it carries out the simulation result schematic diagram of the harmonic wave that emulation obtained for adopting Cadence spectre to gain variable amplifier of the present invention, as seen from the figure, when gain is 6dB, input signal is the 1MHz sine wave, power is 0dBm, and the first-harmonic of 1MHz is than the high 93.01dB of three order harmonicses of 3MHz.

Below further specify how to require to design a gain variable amplifier of the present invention by a specific embodiment according to reality.

For example, the gain ranging of actual needs gain variable amplifier is-5.75dB is to 6dB, and gain step size is 0.25dB, uses TSMC0.18um technology, requires gain fluctuation in the 4MHz signal bandwidth less than 0.1dB.3 rank signal intermodulation points of output are greater than 30dBm.

Gain function according to above-mentioned requirements and gain variable amplifier of the present invention: Can select a=72, thus, can adopt the resistance of 144 same sizes to connect and form the series resistance circuit, in order to reduce resistor area, the resistance of each resistance can be chosen 500 Ω, to reduce the contribution of resistance to equivalent input noise; And each MOS transistor that the beginning circuit comprises, channel length can be selected minimum length 0.18um for use, and channel width can select for use 0.22um to reduce parasitic capacitance as far as possible, and the structure of switching circuit can be as shown in Figure 3.

The design of corresponding decoding circuit can use the Verilog hardware description language to write, and is converted to the real figure circuit by tool software again.Decoding circuit only need guarantee that under the gain controlling word of correspondence the node of corresponding gain is connected with the input of operational amplifier.

In sum, gain variable amplifier of the present invention will as each MOS transistor of switch from signal path move away from, can reduce of the influence of each MOS transistor thus to input resistance and feedback resistance resistance, make gain controlling more accurate.On the other hand since each MOS transistor not on signal path, with respect to existing gain variable amplifier, because of each MOS transistor because source-drain voltage changes the nonlinear effect of generation also can correspondingly reduce.This be because: the series resistance circuit that the present invention adopts is in series numerous resistance, and the node that links to each other with resistance at resistance is connected to the operational amplifier input by MOS transistor.Each MOS transistor is all at the input of operational amplifier, rather than on direct signal path.Because the gain of operational amplifier is very high, be input to the signal of operational amplifier input and faint, and the input impedance of the operational amplifier under the CMOS technology is very big, so to leak two ends pressure drop minimum each MOS transistor source, non-linearly reduces greatly so MOS transistor is brought.In addition, all resistance all is directly to link to each other in the series resistance circuit of the present invention, does not have the accuracy of metal-oxide-semiconductor resistance influence gain.In addition, in existing gain variable amplifier, the width of each mos transistor switch must be enough big, to reduce the conducting resistance of MOS transistor, but the MOS transistor width is excessive, can cause the parasitic capacitance of mos transistor switch to become big, thereby the bandwidth of operation of gain variable amplifier is descended.And each mos transistor switch of the present invention is not on signal path, the conducting resistance of mos transistor switch can not exert an influence to the performance of gain variable amplifier, so the MOS transistor width can be reduced as far as possible, and then improve the bandwidth of operation of gain variable amplifier.

The foregoing description just lists expressivity principle of the present invention and effect is described, but not is used to limit the present invention.Any personnel that are familiar with this technology all can make amendment to the foregoing description under spirit of the present invention and scope.Therefore, the scope of the present invention should be listed as claims.

Claims (5)

1. gain variable amplifier is characterized in that comprising:
Operational amplifier;
The series resistance circuit that at least one 1 ends are connected described operational amplifier output terminal and are in series by a plurality of resistance as signal incoming end, the other end;
With a plurality of nodes of each bar series resistance circuit and a switching circuit that input is connected of described operational amplifier, it comprises a plurality of controlled switchs, be used to control the break-make of an input of a plurality of nodes of each bar series resistance circuit and described operational amplifier, so that the part resistance in each bar series resistance circuit is as the input resistance of described operational amplifier, all the other resistance feedback resistance as described operational amplifier;
Decoding circuit is used for the control signal that inserts is deciphered the switching signal that is used to control described a plurality of controlled switch switchings with output.
2. gain variable amplifier as claimed in claim 1, it is characterized in that: described switching circuit comprises a plurality of first controlled switchs, a plurality of second controlled switch and a plurality of the 3rd controlled switch, wherein, a node, the other end of a series resistance circuit of an end of each first controlled switch connection are connected with an end of one second controlled switch; One end of each second controlled switch connects a plurality of first controlled switchs, the other end connects one the 3rd controlled switch; One end of each the 3rd controlled switch connects the input that a plurality of second controlled switchs, the other end all connect described operational amplifier.
3. gain variable amplifier as claimed in claim 2 is characterized in that: first controlled switch, second controlled switch and the 3rd controlled switch all adopt metal-oxide-semiconductor.
4. gain variable amplifier as claimed in claim 1 is characterized in that: the resistance that same series resistance circuit comprised is all identical.
5. gain variable amplifier as claimed in claim 1 is characterized in that: described operational amplifier comprises that DC current gain is not less than the amplifier of 60dB.
CN2011100971064A 2011-04-18 2011-04-18 Variable-gain amplifier CN102270972A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2011100971064A CN102270972A (en) 2011-04-18 2011-04-18 Variable-gain amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2011100971064A CN102270972A (en) 2011-04-18 2011-04-18 Variable-gain amplifier

Publications (1)

Publication Number Publication Date
CN102270972A true CN102270972A (en) 2011-12-07

Family

ID=45053153

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2011100971064A CN102270972A (en) 2011-04-18 2011-04-18 Variable-gain amplifier

Country Status (1)

Country Link
CN (1) CN102270972A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102931935A (en) * 2012-11-26 2013-02-13 昆山北极光电子科技有限公司 Low-cost program-controlled amplification circuit
CN102931995A (en) * 2012-11-26 2013-02-13 昆山北极光电子科技有限公司 Low-cost rapid digital-analog conversion method
CN102931933A (en) * 2012-11-15 2013-02-13 贵州航天电器股份有限公司 Proportion-adjustable multiway universal programmable voltage amplification module
CN103208971A (en) * 2012-01-13 2013-07-17 上海创远仪器技术股份有限公司 Controllable gain circuit
CN104022746A (en) * 2014-06-20 2014-09-03 威海北洋光电信息技术股份公司 Operational amplifier circuit with fixed bandwidth and real-time variable gain
CN104682903A (en) * 2015-01-19 2015-06-03 广西师范大学 Variable gain bandpass amplification circuit and switching control method for variable gain bandpass amplification circuit
CN105490647A (en) * 2014-10-07 2016-04-13 美国亚德诺半导体公司 Wide range transimpedance amplifier
CN106053910A (en) * 2016-05-24 2016-10-26 中国电子科技集团公司第四十研究所 Circuit eliminating influence of switch on-resistance on circuit gain
CN108476580A (en) * 2016-02-01 2018-08-31 锋翔科技有限公司 The automatic power controller of multiple illumination arrays
CN110618309A (en) * 2019-09-20 2019-12-27 北京大学 Semiconductor detector leakage current measuring device and measuring method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001298337A (en) * 2000-04-12 2001-10-26 Denso Corp Variable gain amplifier circuit
US20090039955A1 (en) * 2007-08-09 2009-02-12 Masahiro Hosoya Variable resistor, filter, variable gain amplifier and integrated circuit using the variable resistor
CN101763496A (en) * 2008-12-24 2010-06-30 国民技术股份有限公司 Radio-frequency card reader for mobile communication terminal
CN201780313U (en) * 2010-07-30 2011-03-30 惠州Tcl移动通信有限公司 Adjustable resistor type testing device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001298337A (en) * 2000-04-12 2001-10-26 Denso Corp Variable gain amplifier circuit
US20090039955A1 (en) * 2007-08-09 2009-02-12 Masahiro Hosoya Variable resistor, filter, variable gain amplifier and integrated circuit using the variable resistor
CN101763496A (en) * 2008-12-24 2010-06-30 国民技术股份有限公司 Radio-frequency card reader for mobile communication terminal
CN201780313U (en) * 2010-07-30 2011-03-30 惠州Tcl移动通信有限公司 Adjustable resistor type testing device

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103208971B (en) * 2012-01-13 2015-10-28 上海创远仪器技术股份有限公司 A kind of controllable-gain circuit
CN103208971A (en) * 2012-01-13 2013-07-17 上海创远仪器技术股份有限公司 Controllable gain circuit
CN102931933A (en) * 2012-11-15 2013-02-13 贵州航天电器股份有限公司 Proportion-adjustable multiway universal programmable voltage amplification module
CN102931995A (en) * 2012-11-26 2013-02-13 昆山北极光电子科技有限公司 Low-cost rapid digital-analog conversion method
CN102931935A (en) * 2012-11-26 2013-02-13 昆山北极光电子科技有限公司 Low-cost program-controlled amplification circuit
CN104022746A (en) * 2014-06-20 2014-09-03 威海北洋光电信息技术股份公司 Operational amplifier circuit with fixed bandwidth and real-time variable gain
CN104022746B (en) * 2014-06-20 2017-08-15 威海北洋光电信息技术股份公司 A kind of discharge circuit of fixed-bandwidth real-time variable gain
CN105490647B (en) * 2014-10-07 2019-07-30 美国亚德诺半导体公司 Wide scope transimpedance amplifier
CN105490647A (en) * 2014-10-07 2016-04-13 美国亚德诺半导体公司 Wide range transimpedance amplifier
CN104682903B (en) * 2015-01-19 2018-04-03 广西师范大学 Variable gain band logical amplifying circuit and can gain band logical amplifying circuit method for handover control
CN104682903A (en) * 2015-01-19 2015-06-03 广西师范大学 Variable gain bandpass amplification circuit and switching control method for variable gain bandpass amplification circuit
CN108476580A (en) * 2016-02-01 2018-08-31 锋翔科技有限公司 The automatic power controller of multiple illumination arrays
CN106053910A (en) * 2016-05-24 2016-10-26 中国电子科技集团公司第四十研究所 Circuit eliminating influence of switch on-resistance on circuit gain
CN110618309A (en) * 2019-09-20 2019-12-27 北京大学 Semiconductor detector leakage current measuring device and measuring method

Similar Documents

Publication Publication Date Title
CN104113212B (en) The apparatus and method of the current balance type of pressure regulator, current sensor and phase equilibrium
CN101777904B (en) Buffer circuit
CN101231535B (en) Method and apparatus for overshoot and undershoot errors correction in analog low pressure difference linear voltage regulator
KR100510515B1 (en) Semiconductor memory device comprising duty cycle correction circuit correcting the duty cycle of clock signal according to process variation
CN100520665C (en) Low-voltage linear voltage adjuster
CN102017399B (en) Amplifier design with biasing and power control aspects
JP5169498B2 (en) Current detection circuit and switching regulator including the current detection circuit
CN1266838C (en) Semiconductor integrated circuit device capable of generating stably constant current under low power voltage
US9379702B2 (en) Sample and hold switch circuit
CN102970789B (en) Driver circuit and related error detection circuit and method
CN101179258B (en) Data receiver circuit, data driver, and display device
JP4765521B2 (en) variable gain amplifier
CN100471051C (en) Low voltage negative feedback transconductance amplifier
CN100527039C (en) Low pressure difference linearity voltage stabilizer for enhancing performance by amplifier embedded compensation network
CN101753159B (en) RF (radio frequency) receiving front end with diversified gaining modes and capable of automatic tuning
CN100485571C (en) Output adjustable voltage-stabilized source
CN102790601B (en) RC (resistance-capacitance) oscillator
CN101038497B (en) Compensation method, compensated regulator and electronic circuit
US7528636B2 (en) Low differential output voltage circuit
CN102668372B (en) Digital charge amplifier and method for converting charge signals into digital signals
CN203038149U (en) Programmable low dropout linear regulator and sampling and feedback circuit thereof
JP2006074228A (en) Current drive type d/a converter and bias circuit thereof
CN102541138B (en) Reference power circuit
CN1739236B (en) Gain variable voltage/current conversion circuit and filter circuit using the same
CN101860327B (en) Cascode amplifier and method for controlling current of the same

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C12 Rejection of a patent application after its publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20111207