Automatic Gain Control Function Research Articles

Analysis and Design of Ultra-Large Dynamic Range CMOS Transimpedance Amplifier With Automatically-Controlled Multi-Current-Bleeding Paths

In this paper, a fully-integrated transimpedance amplifier with ultra-large dynamic range and automatic gain control function is presented. By first deploying three AGC-controlled current paths in the low noise pre-amplifier, the transimpedance amplifier (TIA) can accommodate a significantly enlarged input current. Meanwhile, the range of automatic transimpedance adjustment is enhanced utilizing the automatic gain control (AGC) circuit, tunable pre-amplifier (PrA), and variable gain amplifier (VGA). Besides the above blocks, the TIA with a size of 1.26 × 1.33 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> also integrates level shifter, post-amplifier, buffer, DC offset cancellation (DCOC), bandgap reference (BGR), and low-dropout regulator (LDO). With a single 3.3-V external supply voltage, the fully integrated TIA in 0.11 μm CMOS achieves a measured input dynamic range up to 7.4 mA@2.5 Gb/s, an input referred noise as low as 137.3 nA and a differential trans-impedance gain of 10 kQ. Taking the bandwidth, dynamic range, and trans-impedance gain into account, the fabricated CMOS TIA demonstrates the largest input dynamic range with maintaining competitive comprehensive performance.

Fast transimpedance preamplifier for a boron-coated multiwire proportional chamber neutron detector

A low-noise and fast preamplifier is needed for the new boron-coated multiwire proportional chamber (MWPC) neutron detector with a delay line readout system to improve position resolution. A transimpedance preamplifier with a rise time of 30ns, a signal-to-noise ratio higher than 40dB, and an automatic gain control function are designed to meet the aforementioned requirements. On the other hand, we also compare it to commercial preamplifiers. Then, the advantages and disadvantages of commercial and in-house preamplifiers are analyzed. The preamplifier is used and tested on a MWPC neutron detector, and results are presented.

2.5 Gbit/s burst‐mode receiver with rapid response and high tolerance to CIDs for PON systems

A 2.5 Gbit/s burst-mode receiver for passive optical network (PON) systems with both a fast receiver settling time of 24.1 ns and a high tolerance to consecutive identical digits (CIDs) of 629 bits, by using a preamplifier with a unique peak-detecting automatic gain control function is developed. It is broadly applicable to the time- and wavelength-division multiplexed-PON systems of NG-PON2, which need a wide dynamic range suitable for a 64-way split and a transmission distance exceeding 40 km.

Inter-channel communication in a multi-channel digital hearing instrument

A multi-channel digital hearing instrument is provided that includes a microphone, an analog-to-digital (A/D) converter, a sound processor, a digital-to-analog (D/A) converter and a speaker. The microphone receives an acoustical signal and generates an analog audio signal. The A/D converter converts the analog audio signal into a digital audio signal. The sound processor includes channel processing circuitry that filters the digital audio signal into a plurality of frequency band-limited audio signals and that provides an automatic gain control function that permits quieter sounds to be amplified at a higher gain than louder sounds and may be configured to the dynamic hearing range of a particular hearing instrument user. The D/A converter converts the output from the sound processor into an analog audio output signal. The speaker converts the analog audio output signal into an acoustical output signal that is directed into the ear canal of the hearing instrument user.

C211 過渡熱伝達分布測定による金属欠損の可視化

In order to realize the reliable inspecting systems, many infrared image sensors are utilized because of their high visual capability not depending on the human visible light condition. Recently, nuclear electric power plant is increasing its usefulness not warm up entire earth system accompanying with human life activity. We are now planning to enhance the infrared inspecting system to carry out the condition based maintenance methodology for nuclear electric power plant. At first, this paper clarifies a relationship between the pixel values constructing infrared image and absolute temperature even though automatic gain control function equipped in infrared CCD camera is activating to get the highest contrast image. Second we demonstrate the absolute temperature visualization, which is the most important inspecting factor in the nuclear power plant, on the bended iron sheet.

5-1 MIMO-OFDM伝送における受信AGCが復調性能に及ぼす影響(第5部門 モバイル送受信機)

5-1 MIMO-OFDM伝送における受信AGCが復調性能に及ぼす影響(第5部門 モバイル送受信機)

A Joint Scheme of AGC and Gain/Phase Mismatch Compensation for QPSK DCR

This paper presents a simple gain/phase blind compensation algorithm with an automatic gain control (AGC) function for the adoption of the AGC function and compensation for gain/phase imbalances in quadrature phase shift keying (QPSK) direct conversion receivers (DCRs). The AGC function is interactively operated with the compensation algorithm for gain/phase imbalances. By detecting the gain sum and difference values between the I-channel and Q-channel, the combined AGC and gain imbalance compensation algorithm provides a simpler DCR architecture.

Adjustment-free LSI chip-set for CD player application

The authors have developed an adjustment-free LSI chip-set for CD player application. This chip set contains an automatic gain control function with which a low modulation amplitude disc is playable. Analog/digital mixed technology is used in this chip-set.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Automatic optical loss compensation with erbium-doped fiber amplifier

The effect of unwanted optical loss varying over 15 dB is automatically offset with an erbium-doped fiber amplifier used in an optical feedback configuration. The loss compensation is possible for signal wavelengths over a 13 nm range centered at about 1550 nm. The system dynamic range for loss fluctuation frequencies is zero to several kilohertz. The proposed loss compensation scheme simultaneously provides an automatic gain control function that stabilizes the gain against slow changes in input signal power or pump power.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A high-gain GaAs amplifier with an AGC Function

A high-gain amplifier consisting of three GaAs monolithic IC chips, a preamplifier, an automatic gain control (AGC) amplifier, and a postamplifier, is developed. The fabricated low-noise low-VSWR amplifier has a 45-dB gain, a 13-dB AGC range, and a 1.6-GHz bandwidth with a power consumption of 2.5 W. It is a promising candidate for use in high-speed data rate transmission systems.

Is AGC beneficial in hearing aids?

Three different functions of Automatic Gain Control (AGC) circuits in hearing aids are distinguished and the evidence for their benefits is considered. The value of AGC's function as a relatively distortion-free means of limiting output has been well established. With regard to compression, the benefit of short-term or 'syllabic' compression has not been demonstrated convincingly. Most evaluations of this type of AGC have looked for increase in speech intelligibility, but theoretical predictions of its effect do not appear to take account of the acoustic cues to consonant contrasts actually used by hearing impaired people, and empirical studies have often used listening conditions which do not give a realistic test of benefit. Relatively little attention has been paid to long-term compression, or to the effect of AGC on comfort rather than intelligibility. Listening tests carried out at the RNID and reported here have shown that AGC can benefit hearing aid users by allowing them to listen to a wider range of sound levels without either strain or discomfort, and, if time constants are well chosen, without adverse effects on speech intelligibility in quiet or in noise.