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A magnetic tunnel junction-based register with separate read and write paths is proposed in this paper. Analysis of the operation of the circuit is performed, and methods for determining the key parameters of the device are presented. The simulation of the circuit is performed in Verilog-A, and the simulation results demonstrate the operational characteristics of the circuit. This new spin-based flip flop offers a 23% reduction in the number of devices and a 23.6% reduction in its dissipated power when compared with a pure CMOS implementation with the added benefit of nonvolatility. A 4-b shifter based on the proposed spin register is presented, too. [ABSTRACT FROM PUBLISHER]

Integrated circuits operated in the near-threshold region exhibit specific merit with high energy efficiency. A near-threshold model is highly required for the circuit design. In this paper, a near-threshold drain current model is proposed based on the surface inversion layer charge model for analyzing digital circuits. The short-channel effect in deep submicrometer is also included in the model. Moreover, the delay and energy parts based on the near-threshold drain current model are derived and integrated in the model. Two process design kits (PDKs) are used for parameter extraction to demonstrate the feasibility of the proposed model. The results show that the proposed model can be used for the near-threshold circuit calculation, with the benefit of high accuracy. [ABSTRACT FROM AUTHOR]

A micromachined thermopile infrared sensor is designed and optimized with high detective sensitivity in the article. A matched chopper operational amplifier with good linearity is implemented for signal processing. Optimizations of the sensor’s structure are proposed by the adjustment of the length of the thermocouple pairs and the filling of the back-etched cavity based on the adopted thermocouple materials. A passivation layer is implemented to minimize the flicker noise of the sensor. Based on the requirement of the optimized thermopile sensor system, both the flicker noise and the low-frequency noise of the system are suppressed for achieving high sensitivity. The chopper operational amplifier circuit with a single-ended closed-loop diagram is specifically designed for signal amplification and noise suppression. The fabricated device shows improved characterizations, with the responsivity of 182.72 V/W, detectivity of $2.47\times 10^{{8}}$ cmHz1/2/W, time constant of 10 ms, and total resistance of 270 $\text{k}\Omega $. The sensitivity of the designed system, including the sensor and the amplifier, is about 15 mV/°C, when the gain is 40 dB and the sensor-target distance is 3 cm. The system shows wide applications in the fields of noncontact temperature measurement and other special applications. [ABSTRACT FROM AUTHOR]

Spin-Torque-Transfer Magnetic Tunnel Junction (STT-MTJ) device shows wide applications in many important scenarios, including magnetic random access memory (MRAM), logic design, and high-frequency application. Its characterizations at the high frequency are studied intensively recently. In this article, the high-frequency properties of the STT-MTJ device are investigated thoroughly, including a de-embedding approach followed by an extraction procedure for removing the influences from the environment and the package. The de-embedding approach is performed on the STT-MTJ device operated at a high frequency, which can be used to calibrate its electrical characteristics by eliminating the environmental influence. After the calibration, the equivalent circuit for the MTJ device at high frequency can be set up, followed by the extraction procedure of the parasitic parameters of the high-frequency-equivalent-circuit. Combined with the extracted parameters, the equivalent circuit can be used for the simulation work with the MTJ device involved in the high-frequency operation. [ABSTRACT FROM AUTHOR]