Structure-functional schemes of analog frequency dividers of harmonic signals are proposed. The schemes are precise for any finite values of amplitudes and frequencies of input signals. Signal ...transformation is fulfilled linearly without amplitude and frequency distortion, i.e. the schemes do not generate harmonics. Dividers do not require an additional filtering of output signals.
Capacitive transduction is ubiquitously employed at macro- and especially micro-scales due to their simple structure and stability. This study proposes a topology for a low-power readout circuit for ...differential capacitive sensors. The circuit includes two switched-capacitor blocks that produce signals that are proportional to the difference and sum of the sense capacitors. Outputs of these two blocks are fed to an analogue divider to produce a pulse whose width is proportional to the ratio of the difference to sum of the sense capacitors. In addition to providing adjustable sensitivity and noise levels, this also reduces the sensitivity of the sensor to common-mode parasitics at the circuit input. The circuit topology was realised in a standard CMOS 0.35 µm technology with a total chip area of 330 µm × 600 µm. The performance of the fabricated circuit was evaluated by pairing it with a micromechanical variable capacitor. Experimental results demonstrated the capability of the circuit to resolve 160 aF of differential capacitance with a total power consumption of 720 µW while remaining insensitive to common-mode parasitic capacitances.
A simple X-ray position detection system based on a MHSP Natal da Luz, H.; Veloso, J.F.C.A.; dos Santos, J.M.F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Letnik:
580, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A simple system for position detection based on a Micro-Hole and Strip Plate (MHSP) using a resistive charge division method was implemented. A thin resistive layer of about 100
Ω between each strip ...(top surface) and between each anode strip (bottom surface) allows us to obtain the actual position in both orthogonal directions. The readout electronics uses only two preamplifiers, a sum and a divider circuit to calculate the interaction point, in each dimension. For a detector filled with 1
atm of pure xenon, position resolutions of less than 300
μm (FWHM) were achieved using 5.9
keV X-rays, for a signal-to-noise ratio (SNR) of 30. For these conditions, a detector gain of about 10
4 and an energy resolution of about 15% were obtained.
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