Wide dynamic range automatic gain control using feed forward and backward technique

Author(s):  
F. A. Mughal ◽  
F. Sultan ◽  
M. Imran
2015 ◽  
Vol 719-720 ◽  
pp. 548-553
Author(s):  
Feng Guo ◽  
Shan Shan Yong ◽  
Zhao Yang Guo ◽  
Xin An Wang ◽  
Guo Xin Zhang

In this paper, a new design strategy for the hardware implementation of hearing aid algorithms is proposed. Two familiar hearing aid algorithms—Wide Dynamic Range Compression (WDRC) and Automatic Gain Control (AGC)—are implemented in one circuit as an example. By putting the common arithmetic procedures into common module, the operation units can be used repeatedly. In this way, the area and power consumption are visibly reduced.


2013 ◽  
Vol 142 ◽  
pp. 261-273
Author(s):  
Bo Zhang ◽  
Yong-Zhong Xiong ◽  
Lei Wang ◽  
Sanming Hu ◽  
Joshua Le-Wei Li

2017 ◽  
Vol 38 (4) ◽  
Author(s):  
Tiezhu Zhu ◽  
Taishan Mo ◽  
Tianchun Ye

AbstractAn optical receiver front-end circuit is designed for passive optical network and fabricated in a 0.18 um CMOS technology. The whole circuit consists of a transimpedance amplifier (TIA), a single-ended to differential amplifier and an output driver. The TIA employs a cascode stage as the input stage and auxiliary amplifier to reduce the miller effect. Current injecting technique is employed to enlarge the input transistor’s transconductance, optimize the noise performance and overcome the lack of voltage headroom. To achieve a wide dynamic range, an automatic gain control circuit with self-adaptive function is proposed. Experiment results show an optical sensitivity of –28 dBm for a bit error rate of 10


1993 ◽  
Vol 93 (2) ◽  
pp. 1217-1217
Author(s):  
Mead C. Killion ◽  
Harry Teder ◽  
Arthur C. Johnson ◽  
Steven P. Hanke

Author(s):  
V. M. Lipka ◽  
V. V. Ryukhtin ◽  
Yu. G. Dobrovolsky

Measurement of periodic optical information signals in the background light noise with a photodetector with extended dynamic range is an urgent task of modern electronics and thus has become the aim of this study. To increase the dynamic range of the photodetector, a new version of the automatic gain control (AGC) circuit has been developed, which consists of an AGC controller, an output photodetector amplifier and an AGC detector. The authors measured the dynamic range of the photodetector when receiving optical radiation with a wavelength of 1064 nm in the power range from 2.10–8 to 2.10–5 W at a modulation frequency of 20 kHz with the AGC on. Under these conditions, the dynamic range of the photodetector was found to be up to 67 dB. If the AGC was off, the dynamic range did not exceed 30 dB. Thus, the study made it possible to create a photodetector with an extended dynamic range up to 67 dB based on a new version of the AGC circuit. The design of the photodetector allowed choosing a useful signal of a particular modulation frequency in the frequency range from 3 to 45 kHz and effectively suppresses the frequencies caused by optical interference in the low frequency range from the frequency of the input signal of constant amplitude up to 3 kHz inclusive. This compensates the current up to 15 mA, which is equivalent to the power of light interference of about 15 mW. Further research should address the issues of reliability of the proposed photodetector design and optimization of its optical system. The photodetector can be used in geodesy and ambient air quality monitoring.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 512
Author(s):  
Binghui Lin ◽  
Mohamed Atef ◽  
Guoxing Wang

A low-power, high-gain, and low-noise analog front-end (AFE) for wearable photoplethysmography (PPG) acquisition systems is designed and fabricated in a 0.35 μm CMOS process. A high transimpedance gain of 142 dBΩ and a low input-referred noise of only 64.2 pArms was achieved. A Sub-Hz filter was integrated using a pseudo resistor, resulting in a small silicon area. To mitigate the saturation problem caused by background light (BGL), a BGL cancellation loop and a new simple automatic gain control block are used to enhance the dynamic range and improve the linearity of the AFE. The measurement results show that a DC photocurrent component up-to-10 μA can be rejected and the PPG output swing can reach 1.42 Vpp at THD < 1%. The chip consumes a total power of 14.85 μW using a single 3.3-V power supply. In this work, the small area and efficiently integrated blocks were used to implement the PPG AFE and the silicon area is minimized to 0.8 mm × 0.8 mm.


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