A Novel differential to single-ended converter for ultra-low-voltage inverter-based OTAs

For the design of inverter-based OTAs with differential input and single-ended output, the differential to single-ended (D2S) converter is a key building block. In fact, the performance of the D2S strongly affects the overall common-mode rejection ratio (CMRR) and input common-mode range (ICMR) of the whole OTA. In recent literature, inverter-based OTAs rely on a D2S topology based on an inverter driving another inverter with the input and output tight together which behaves as a “diode" connected device to implement a voltage gain approximately equal to -1. However, since this approach is based on the matching of the inverters, the performance of this D2S results sensitive to PVT variations if the bias point of the inverters is not properly stabilized. In this paper we present a novel topology of inverterbased D2S converter, exploiting an auxiliary, standard-cell-based, error amplifier and a local feedback loop. The proposed D2S, compared to the conventional one, exhibits higher CMRR, improved ICMR and better robustness with respect to PVT variations.We present also an ULV, standard-cell-based OTA, which exploits the proposed D2S converter and shows excellent performance figures of merit with low area footprint

Long-term memory for spatial frequency:A non-replication

Reports on stability of spatial frequency in short-term memory span have confirmed low-level perceptual memory mechanism in early visual processing. However, some studies have also claimed evidence for high-fidelity perceptual long-term storage of spatial frequency. We report an attempted replication of Magnussen et al. (Psychol Sci 14:74–76, 2003) where participants were asked to discriminate the spatial frequency of a reference grating from a test stimulus after intervals of 5 s or 24 h. Group thresholds after 24 h were significantly higher than after 5 s, therefore failing to support long-term storage of spatial frequency

A 0.3 V, rail-to-rail, ultralow-power, non-tailed, body-driven, sub-threshold amplifier

A novel, inverter-based, fully differential, body-driven, rail-to-rail, input stage topology is proposed in this paper. The input stage exploits a replica bias control loop to set the common mode current and a common mode feed-forward strategy to set its output common mode voltage. This novel cell is used to build an ultralow voltage (ULV), ultralow-power (ULP), two-stage, unbuffered operational amplifier. A dual path compensation strategy is exploited to improve the frequency response of the circuit. The amplifier has been designed in a commercial 130 nm CMOS technology from STMicroelectronics and is able to operate with a nominal supply voltage of 0.3 V and a power consumption as low as 11.4 nW, while showing about 65 dB gain, a gain bandwidth product around 3.6 kHz with a 50 pF load capacitance and a common mode rejection ratio (CMRR) in excess of 60 dB. Transistor-level simulations show that the proposed circuit outperforms most of the state of the art amplifiers in terms of the main figures of merit. The results of extensive parametric and Monte Carlo simulations have demonstrated the robustness of the proposed circuit to PVT and mismatch variations

A 0.3V Rail-to-Rail Three-Stage OTA With High DC Gain and Improved Robustness to PVT Variations

This paper presents a novel 0.3V rail-to-rail body-driven three-stage operational transconductance amplifier (OTA). The proposed OTA architecture allows achieving high DC gain in spite of the bulk-driven input. This is due to the doubled body transconductance at the first and third stages, and to a high gain, gate-driven second stage. The bias current in each branch of the OTA is accurately set through gate-driven or bulk-driven current mirrors, thus guaranteeing an outstanding stability of main OTA performance parameters to PVT variations. In the first stage, the input signals drive the bulk terminals of both NMOS and PMOS transistors in a complementary fashion, allowing a rail-to-rail input common mode range (ICMR). The second stage is a gate-driven, complementary pseudo-differential stage with an high DC gain and a local CMFB. The third stage implements the differential-to-single-ended conversion through a body-driven complementary pseudo-differential pair and a gate-driven current mirror. Thanks to the adoption of two fully differential stages with common mode feedback (CMFB) loop, the common-mode rejection ratio (CMRR) in typical conditions is greatly improved with respect to other ultra-low-voltage (ULV) bulk-driven OTAs. The OTA has been fabricated in a commercial 130nm CMOS process from STMicroelectronics. Its area is about 0.002 mm2 , and power consumption is less than 35nW at the supply-voltage of 0.3V. With a load capacitance of 35pF, the OTA exhibits a DC gain and a unity-gain frequency of about 85dB and 10kHz, respectively

A 0.3 V rail-to-rail ultra-low-power OTA with improved bandwidth and slew rate

In this paper, we present a novel operational transconductance amplifier (OTA) topology based on a dual-path body-driven input stage that exploits a body-driven current mirror-active load and targets ultra-low-power (ULP) and ultra-low-voltage (ULV) applications, such as IoT or biomedical devices. The proposed OTA exhibits only one high-impedance node, and can therefore be compensated at the output stage, thus not requiring Miller compensation. The input stage ensures rail-to-rail input common-mode range, whereas the gate-driven output stage ensures both a high open-loop gain and an enhanced slew rate. The proposed amplifier was designed in an STMicroelectronics 130 nm CMOS process with a nominal supply voltage of only 0.3 V, and it achieved very good values for both the small-signal and large-signal Figures of Merit. Extensive PVT (process, supply voltage, and temperature) and mismatch simulations are reported to prove the robustness of the proposed amplifier

Surgical management of Glioma Grade 4: technical update from the neuro-oncology section of the Italian Society of Neurosurgery (SINch®): a systematic review

Purpose: The extent of resection (EOR) is an independent prognostic factor for overall survival (OS) in adult patients with Glioma Grade 4 (GG4). The aim of the neuro-oncology section of the Italian Society of Neurosurgery (SINch®) was to provide a general overview of the current trends and technical tools to reach this goal. Methods: A systematic review was performed. The results were divided and ordered, by an expert team of surgeons, to assess the Class of Evidence (CE) and Strength of Recommendation (SR) of perioperative drugs management, imaging, surgery, intraoperative imaging, estimation of EOR, surgery at tumor progression and surgery in elderly patients. Results: A total of 352 studies were identified, including 299 retrospective studies and 53 reviews/meta-analysis. The use of Dexamethasone and the avoidance of prophylaxis with anti-seizure medications reached a CE I and SR A. A preoperative imaging standard protocol was defined with CE II and SR B and usefulness of an early postoperative MRI, with CE II and SR B. The EOR was defined the strongest independent risk factor for both OS and tumor recurrence with CE II and SR B. For intraoperative imaging only the use of 5-ALA reached a CE II and SR B. The estimation of EOR was established to be fundamental in planning postoperative adjuvant treatments with CE II and SR B and the stereotactic image-guided brain biopsy to be the procedure of choice when an extensive surgical resection is not feasible (CE II and SR B). Conclusions: A growing number of evidences evidence support the role of maximal safe resection as primary OS predictor in GG4 patients. The ongoing development of intraoperative techniques for a precise real-time identification of peritumoral functional pathways enables surgeons to maximize EOR minimizing the post-operative morbidity

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011