Current mismatch reduction in charge pumps using regulated current stealing-injecting transistors for PLLs

A charge pump for phase locked loops (PLL) with a novel current mismatch compensation technique is proposed. The proposed circuit uses a simple yet effective current stealing-injecting (CSI) technique and feedback to reduce mismatch between the negative-channel-metal-oxide (NMOS) and positive-channel-metal-oxide (PMOS) transistors. The current stealing transistor steals the current from a replica branch and mirrors it to the output where it is added to the output branch by the injecting transistor. A feedback mechanism is used to set the drain voltages of both branches to be equal and mitigate channel length modulation and ensure high accuracy. The proposed circuit was designed on Silterra 130nm technology and simulated using Cadence Spectre. The simulation results show that the proposed circuit yields a maximum of 0.107% and minimum of 0.00465% current mismatch while operating at a low supply voltage of 800mV for a range of 100mV to 700mV. The proposed design uses only one rail-to-rail op amp for compensating the mismatch and an addition of 4 transistors and utilizing 75% of the supply voltage for high voltage controlled oscillator (VCO) tuning range.

DVCC-based Low-power RF Filter with 32 nm CNFETs

This work presents a wide-band active filter for RF receiver. The design uses Carbon Nanotube-FET (CNFET) based differential voltage current conveyor (DVCC) for the implementation of the proposed filter. The filter is designed to operate Ku-band frequencies (12-18 GHz), which is used in satellite communication. Additionally, CMOS based circuit and CNFET-based circuit for DVCC are compared for the performance evaluation. HSPICE simulations have been carried out to test the design aspects of the circuit. The CNFET-based circuit has better results in terms of 60 % reduction in the power consumption and about six times improvement in the bandwidth. The filter utilizes low supply voltage of 0.9 V and consumes 524 µW only. The proposed filter outperforms the existing CMOS-based designs which suggests its usage for low-power high-frequency analog circuits.

Analysis of Charge Pump Topologies for High Voltage Mobile Microphone Applications

This paper presents a novel analysis of charge pump topologies for very high voltage capacitive drive micro electro-mechanical system microphones. For the application, the size and power consumption are sought to be minimized, and a voltage gain of 36 is achieved from a 5 V supply. The analysis compares known charge pump topologies, taking into consideration on resistance of transistors and parasitic capacitances of transistors and capacitors in a 180 nm silicon-on-insulator process. The analysis finds that the Pelliconi charge pump topology is optimal for generating very high bias voltages for micro electro-mechanical system microphones from a low supply voltage when the power consumption and area are limited by the application.

Simulation and Performance Analysis of Dielectric Modulated Dual Source Trench Gate TFET Biosensor

In this paper, a dielectric modulated double source trench gate tunnel FET (DM-DSTGTFET) based on biosensor is proposed for the detection of biomolecules. DM-DSTGTFET adopts double source and trench gate to enhance the on-state current and to generate bidirectional current. In the proposed structure, two cavities are etched over 1 nm gate oxide for biomolecules filling. A 2D simulation in the Technology Computer-Aided Design (TCAD) is adopted for the analysis of sensitivity study. The results show that under low supply voltage, the current sensitivity of the DM-DSTGTFET is as high as 1.38 × 105, and the threshold voltage sensitivity can reach 1.2 V. Therefore, the DM-DSTGTFET biosensor has good application prospects due to its low power consumption and high sensitivity.

Low-Voltage Integrated Circuits Design and Application

One of the most challenging tasks for analog and digital designers is to maintain the circuit performances by developing novel circuit structures, robust, reliable, and capable of operating with low supply voltage [...]