This thesis describes the design of a low-power speech detector chip. It will be used between an electret microphone and a microcontroller and will generate a digital wake-up signal for the microcontroller when the audio signal is sufficiently “speechlike” to initiate higher-level processing of the amplified audio signal. The rest of the time, the microcontroller will sleep and consume nearly n...

This paper describes a CMOS optical preamplifier suitable for free-space, infrared wireless communications. The design is differential for improved power supply noise rejection, and an active cancellation scheme is used for eliminating dc photocurrents that are generated by ambient light. Making use of a 0.35-µm CMOS process, the preamplifier provides a transimpedance gain of 20 kΩ over a bandw...

In high speed ADC, speed limiting element is comparator. This paper describes a very high speed and low offset preamplifierlatch comparator. The threshold and width of the new comparator can be reduced to the mV range, the resolution and the dynamic characteristics are good. Based on TSMC 0.18um CMOS process model, simulated results show the comparator can work under ultra high speed clock freq...

The microwave circuit simulator MMICAD can be used to analyze and optimize the small-signal conversion and noise performance of a mixer-preamplifier. The mixer is represented as a noisy five-frequency five-port network using imported conversion and noise correlation matrices, with MMICAD’s NCSCOR5 element which contains five correlated noise sources.

This paper discusses a new kind of distortion mechanism found in transistorized audio power amplifiers. It is shown that this distortion arises from the multistage feedback loop found in most high-quality amplifiers, provided that the open-loop transient response of the power amplifier is slower than the transient response of the preamplifier. The results of the analysis are verified by measure...

The AC response measurement system is presented. System structure, operation and main units operation are described. The connection setup for a few most common tasks is presented. The obtained results are given. It has been indicated that AC response can be investigated for ultrasonic preamplifier, matching transformer, system filters and ultrasonic transducers. The system is controlled by a pe...

We describe a high impedance audiofrequency preamplifier and present au-diofrequency noise spectra for 2N4416 and U311 JF'ET's, in a temperature range from room temperature to 80O.K. It is found that optimum noise performance is obtained at-140'K. We present an analysis of some of the sources of noise. Amplifier input capacitance is a.lso measured and discussed.

The SLD PADS electronics consist of over 9000 channels of charge-sensitive preamplifiers followed by integrated sample/hold data storage, digitizing, and readout circuitry. This paper uses computer simulation techniques to analyze critical performance parameters of the preamplifier hybrid including its interactions with the detector system. Simulation results are presented and verified with mea...