84 fs Yb-doped fiber nonlinear amplifier

A 0.6-V to 1-V Audio ΔΣ Modulator in 65 nm CMOS with 90.2 dB SNDR at 0.6-V

VLSI Design ◽

10.1155/2013/353080 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Liyuan Liu ◽

Dongmei Li ◽

Zhihua Wang

Keyword(s):

Power Dissipation ◽

Total Power ◽

Third Order ◽

Power Cost ◽

Threshold Voltages ◽

Nonlinear Amplifier ◽

Amplifier Gain ◽

Low Threshold ◽

Single Comparator ◽

Circuit Techniques

This paper presents a discrete time, single loop, third order ΔΣ modulator. The input feed forward technique combined with 5-bit quantizer is adopted to suppress swings of integrators. Harmonic distortions as well as the noise mixture due to the nonlinear amplifier gain are prevented. The design of amplifiers is hence relaxed. To reduce the area and power cost of the 5-bit quantizer, the successive approximation quantizer with only a single comparator instead of traditional flash quantizer is employed. Fabricated in 65 nm CMOS, the modulator achieves 95 dB peak SNDR at 1-V supply with 24 kHz. Thanks to low swing circuit techniques and low threshold voltages of devices, the peak SNDR maintains 90.2 dB under 0.6-V low supply. The total power dissipation is 371 μW at 1-V and drops to only 133 μW at 0.6-V.

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An automatic phase picker for local and teleseismic events

Bulletin of the Seismological Society of America ◽

10.1785/bssa0770041437 ◽

1987 ◽

Vol 77 (4) ◽

pp. 1437-1445

Author(s):

M. Baer ◽

U. Kradolfer

Keyword(s):

Arrival Time ◽

Detection Algorithm ◽

Dynamic Threshold ◽

Data Set ◽

Automatic Phase ◽

Nonlinear Amplifier ◽

First Motion ◽

Transient Events ◽

Teleseismic Events ◽

Automatic Detection Algorithm

Abstract An automatic detection algorithm has been developed which is capable of time P-phase arrivals of both local and teleseismic earthquakes, but rejects noise bursts and transient events. For each signal trace, the envelope function is calculated and passed through a nonlinear amplifier. The resulting signal is then subjected to a statistical analysis to yield arrival time, first motion, and a measure of reliability to be placed on the P-arrival pick. An incorporated dynamic threshold lets the algorithm become very sensitive; thus, even weak signals are timed precisely. During an extended performance evaluation on a data set comprising 789 P phases of local events and 1857 P phases of teleseismic events picked by an analyst, the automatic picker selected 66 per cent of the local phases and 90 per cent of the teleseismic phases. The accuracy of the automatic picks was “ideal” (i.e., could not be improved by the analyst) for 60 per cent of the local events and 63 per cent of the teleseismic events.

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