A 50 MHz variable gain amplifier cell in 2 mu m CMOS

Gomez, Roderick A.; Abidi, A.A.

doi:10.1109/cicc.1991.164021

Cited by 6 publications

(5 citation statements)

References 2 publications

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“…The control voltage can be swept to control the gain of the amplifier. When is at ground, is shut down, there's no diversion current and amplifier works at maximum gain mode in which transconductance of 1 is as in (2). As the control voltage increases, is gradually turned on and the diversion current starts to flow through and .…”

Section: Current Diversion Techniquementioning

confidence: 98%

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Current diversion technique for the design of broadband variable gain amplifiers

Pham

Kang

Lin

2010

2010 IEEE International Conference on Communication Systems

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This paper presents a new technique for the design of broadband variable gain amplifiers (VGA). The proposed technique uses current diversion concept to provide gain variation function for the broadband amplifier. Since gain variation is achieved without compromising voltage headroom, it facilitates low power design of the VGA. Since DC levels of output signals of each stage stay constant, it also enables DC coupling between cascaded stages of the VGA. Both voltage controlled and digital controlled VGAs can be realized using the proposed technique. To demonstrate the feasibility of the technique, a digital controlled VGA was implemented in 90 nm CMOS which has bandwidth from 10 MHz to 2.8 GHz, gain ranging from 22 to 42.9 dB with 3 dB gain steps, and power consumption of 1.94 mW.

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Section: Current Diversion Techniquementioning

confidence: 98%

“…• Variable transconductance of a MOS in saturation achieved by the bias current on the MOS device 1 [2], [3]. This technique is also called current splitting or current steering.…”

Section: Gain Variation Techniquesmentioning

confidence: 99%

Current diversion technique for the design of broadband variable gain amplifiers

Pham

Kang

Lin

2010

2010 IEEE International Conference on Communication Systems

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“…Various techniques to control the gain of a VGA in CMOS technologies include varying: (1) the effective trans-conductance of input stage [1,15,16], (2) the load resistance, (3) and the feedback network resistances of a high gain amplifier [17]. Detailed classification of VGAs may be found in [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

A 0.74 mW, linear-in-dB, constant bandwidth, variable gain amplifier based on zero-pole repositioning technique

Baghtash

2015

Analog Integr Circ Sig Process

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A zero-pole repositioning based variable gain amplifier is presented in this paper. The operational principle of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by simulation in TSMC 0.18 lm standard CMOS technology. Owing to the cutting-edge structure, the proposed circuit demonstrates a very low power consumption of 0.74 mW and a wide tuning range of 83 dB. The proposed structure benefits from linear-in-dB and constant bandwidth specifications. The linear-in-dB gain range of structure is about 70 dB. The structure draws about 413 lA from 1.8 V power supply and regarding this low power consumption, it shows a lower and upper 3-dB cutoff frequencies of 8 Hz and 8.1 MHz, respectively. Process and temperature variation analysis of the circuit is also investigated through Monte Carlo and corner case analysis in order to verify the well-robustness of the structure. The transient sinusoidal response analysis is also done to verify the proposed VGA's stability.

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“…The main function of the VGA is to provide a fixed voltage output for different input signal levels, and thus the dynamic range of the overall system is greatly improved. It has been widely used in wireless RF transceivers such as Bluetooth, wireless local area networks (WLANs), GSM WCDMA, ultra-wideband (UWB), and magnetic disk-drive read channel applications [2], [3], [5], [15], [19]. The VGA should meet requirements of large dynamic range and good dB linearity.…”

Section: Introductionmentioning

confidence: 99%

“…For DCR applications, it should also be able to efficiently suppress the dc offset. In CMOS technology, basically there are three methods to control the gain of a VGA, namely, by varying: 1) the transconductance of a MOS device operated in the saturation region [2]; 2) the load resistance [3]; and 3) the source degeneration resistance which is often implemented by a MOS device operated in the linear region [4]. Among them, the last method has the advantages of good linearity, low noise figure, and low power dissipation because the source degeneration does not impose any penalty on voltage headroom.…”

Section: Introductionmentioning

confidence: 99%

A CMOS VGA With DC Offset Cancellation for Direct-Conversion Receivers

Zheng

Yan

2009

IEEE Trans. Circuits Syst. I

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A CMOS dB-linear variable gain amplifier (VGA) with a novel I/Q tuning loop for dc-offset cancellation is presented. The CMOS dB-linear VGA provides a variable gain of 60 dB while maintaining its 3-dB bandwidth greater than 2.5 MHz. A novel exponential circuit is proposed to obtain the dB-linear gain control characteristics. Nonideal effects on dB linearity are analyzed and the methods for improvement are suggested. A varying-bandwidth LPF is employed to achieve fast settling. The chip is fabricated in a 0.35-m CMOS technology and the measurement results demonstrate the good dB linearity of the proposed VGA and show that the tuning loop can effectively remove dc offset and suppress I/Q mismatch effects simultaneously.

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A 50 MHz variable gain amplifier cell in 2 mu m CMOS

Abstract: A CMOS Variable Gain Amplifier is described for possible use in disk drive read channels. The 0.9 sq mm cell attains a 30 dB range of variable gain with 50 MHz bandwidth, requires a single 5V supply, and dissipates 150 mW.

Cited by 6 publications

References 2 publications

Current diversion technique for the design of broadband variable gain amplifiers

Current diversion technique for the design of broadband variable gain amplifiers

A 0.74 mW, linear-in-dB, constant bandwidth, variable gain amplifier based on zero-pole repositioning technique

A CMOS VGA With DC Offset Cancellation for Direct-Conversion Receivers

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