A low-power wide dynamic range envelope detector

Zhak, S.M.; Baker, Maureen; Sarpeshkar, Rahul

doi:10.1109/jssc.2003.817599

Cited by 73 publications

(36 citation statements)

References 12 publications

(18 reference statements)

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“…And V TH is the knee voltage of the DMGC; V LH is the reference voltage of the gain control unit. The envelop detector [11] senses the system output envelop voltage V PD and compares it with the V TH . The comparison result determines which kind of feedback network is used in the feedback to perform the sound signal amplification.…”

Section: System Implementationmentioning

confidence: 99%

“…In (15), G is the gain of the envelop detector, and s is the time constant which is determined by the cut-off frequency of the envelop detector [11][12][13][14][15]. To determine the compression ratio, a factor denoted as m is defined below:…”

Section: Gain Controlmentioning

confidence: 99%

“…For the envelop detector, with the sound level increased, the higher system output envelop voltage V PD would lead to lower V PD 0 [11]. Hence, the quiescent current in M 1,2,3 can be reduced in the AGC mode and expressed as follows:…”

Section: Improved Power Efficiencymentioning

confidence: 99%

See 2 more Smart Citations

Dual-mode gain control for a 1 V CMOS hearing aid device with enhanced accuracy and energy-efficiency

Yang

Liu

et al. 2012

Analog Integr Circ Sig Process

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A dual-mode gain control (DMGC) technique is presented for accurate and energy-efficient pre-amplification in the front-end system of a hearing aid chip. Compared with the conventional automatic gain control (AGC) approach, the DMGC approach is characterized by an amplification switching mechanism between the prolinearity discrete gain setting mode and the energy-efficient AGC mode. Thus, the total harmonic distortion (THD) should be significantly improved without incurring any degradation concerning other performances parameters (e.g. gain, noise and power consumption). In order to further enhance the system power efficiency, a self currentadapting (SCA) circuit design technique is proposed. Such SCA circuits are capable of automatically adjusting the bias current in accordance with the sound level. A prototype chip was designed with a 0.13 lm standard CMOS process and tested with 1 V supply voltage. The measurement results show that, for a typical output level of 500 mV p-p , the THD is somewhere below -64 dB, achieving approximately ten times reduction compared to the previously reported works. The power consumption of less than 45 lW has also been obtained. In addition, the typical input referred noise is only 2 lV rms and the maximum gain attainable is up to 39 dB.

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Section: System Implementationmentioning

confidence: 99%

Section: Gain Controlmentioning

confidence: 99%

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Dual-mode gain control for a 1 V CMOS hearing aid device with enhanced accuracy and energy-efficiency

Yang

Liu

et al. 2012

Analog Integr Circ Sig Process

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“…1(b). A 'command current' that is proportional to the desired noise amplitude is determined by a prior stored measurement with a low-noise neural amplifier and a wide-dynamic-range -to-envelope detector described in [16]. This current is input to the adaptive Step response of the amplifier's bias current due to a step change in the control input current.…”

Section: B Adaptive Power Biasing Of Neural Amplifiers In Multi-elecmentioning

confidence: 99%

Low-Power Circuits for Brain-Machine Interfaces

Sarpeshkar

Wattanapanitch

Rapoport

et al. 2007

2007 IEEE International Symposium on Circuits and Systems (ISCAS)

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Abstract-This paper presents work on ultra-low-power circuits for brain-machine interfaces with applications for paralysis prosthetics, stroke, Parkinson's disease, epilepsy, prosthetics for the blind, and experimental neuroscience systems. The circuits include a micropower neural amplifier with adaptive power biasing for use in multi-electrode arrays; an analog linear decoding and learning architecture for data compression; low-power radio-frequency (RF) impedance-modulation circuits for data telemetry that minimize power consumption of implanted systems in the body; a wireless link for efficient power transfer; mixed-signal system integration for efficiency, robustness, and programmability; and circuits for wireless stimulation of neurons with power-conserving sleep modes and awake modes. Experimental results from chips that have stimulated and recorded from neurons in the zebra finch brain and results from RF power-link, RF data-link, electrode-recording and electrode-stimulating systems are presented. Simulations of analog learning circuits that have successfully decoded prerecorded neural signals from a monkey brain are also presented.

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“…The rectifier is one of the fundamental blocks that is required in a variety of wearable biomedical systems that incorporate online processing of a biological signal. Low-power/low-frequency rectifiers are needed in bionic implants for the deaf, hearing aids and speech recognition systems [1,2]. Functional electrical stimulation is becoming a promising technique to restore functions of paralysed body organs.…”

Section: Introductionmentioning

confidence: 99%