No abstract

In this paper, a memristor with structure of Cu/ PEDOT:PSS/ Ta was fabricated at room temperature. The conductance could be modulated incrementally by pulse sequences. The amplitude, width, frequency and quantity of the pulse sequence play important roles in conductance variation, which is similar to the weight of synapses. Several important synaptic learning behaviors such as short-term potentiation (STP), long-term potentiation (LTP) and spike-timing dependent plasticity (STDP) were emulated by this memristor, respectively. It is found that the movement of Cu ions is critical for this device.

No abstract

This paper proposes a low-power delta-sigma capacitance-to-digital converter (CDC) for a capacitive sensor. The input of the capacitive sensor employs a zoomed-in technique with the offset capacitor to extend the input capacitance range. The proposed CDC uses a third-order switched capacitor deltasigma modulator to provide a digital output, based on a cascade of integrators with a feed forward (CIFF) structure. The current-starved operational transconductance amplifiers (OTAs) are applied in the delta-sigma modulator's first integrator to improve the current efficiency and reduce the power consumption. An autozeroing technique is used in the OTAs to reduce their offset and noise. The circuit was implemented in a 0.18-µm CMOS technology and occupies an area of 0.496 mm 2. The measurable capacitance range of the CDC can be varied from 0 to 8 pF. In a measurement time of 0.8 ms, the delta-sigma CDC achieved a 12.7 effective number of bits while consuming 18.6-µA current from a 2-V supply voltage. INDEX TERMS Capacitive sensors, delta-sigma modulation, low power.

No abstract