1,704 research outputs found

    Phase Locked Loop Test Methodology

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    Phase locked loops are incorporated into almost every large-scale mixed signal and digital system on chip (SOC). Various types of PLL architectures exist including fully analogue, fully digital, semi-digital, and software based. Currently the most commonly used PLL architecture for SOC environments and chipset applications is the Charge-Pump (CP) semi-digital type. This architecture is commonly used for clock synthesis applications, such as the supply of a high frequency on-chip clock, which is derived from a low frequency board level clock. In addition, CP-PLL architectures are now frequently used for demanding RF (Radio Frequency) synthesis, and data synchronization applications. On chip system blocks that rely on correct PLL operation may include third party IP cores, ADCs, DACs and user defined logic (UDL). Basically, any on-chip function that requires a stable clock will be reliant on correct PLL operation. As a direct consequence it is essential that the PLL function is reliably verified during both the design and debug phase and through production testing. This chapter focuses on test approaches related to embedded CP-PLLs used for the purpose of clock generation for SOC. However, methods discussed will generally apply to CP-PLLs used for other applications

    An embedded tester core for mixed-signal System-on-Chip circuits

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    A built-in self-test technique for high speed analog-to-digital converters

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    Fundação para a Ciência e a Tecnologia (FCT) - PhD grant (SFRH/BD/62568/2009

    A DLL Based Test Solution for 3D ICs

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    Integrated circuits (ICs) are rapidly changing and vertical integration and packaging strategies have already become an important research topic. 2.5D and 3D IC integrations have obvious advantages over the conventional two dimensional IC implementations in performance, capacity, and power consumption. A passive Si interposer utilizing Through-Silicon via (TSV) technology is used for 2.5D IC integration. TSV is also the enabling technology for 3D IC integration. TSV manufacturing defects can affect the performance of stacked devices and reduce the yield. Manufacturing test methodologies for TSVs have to be developed to ensure fault-free devices. This thesis presents two test methods for TSVs in 2.5D and 3D ICs utilizing Delay-Locked Loop (DLL) modules. In the test method developed for TSVs in 2.5D ICs, a DLL is used to determine the propagation delay for fault detection. TSV faults in 3D ICs are detected through observation of the control voltage of a DLL. The proposed test methods present a robust performance against Process, supply Voltage and Temperature (PVT) variations due to the inherent feedback of DLLs. 3D full-wave simulations are performed to extract circuit level models for TSVs and fragments of an interposer wires using HFSS simulation tools. The extracted TSV models are then used to perform circuit level simulations using ADS tools from Agilent. Simulation results indicate that the proposed test solution for TSVs can detect manufacturing defects affecting the TSV propagation delay

    Viking '75 spacecraft design and test summary. Volume 1: Lander design

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    The Viking Mars program is summarized. The design of the Viking lander spacecraft is described

    Phase Noise Analyses and Measurements in the Hybrid Memristor-CMOS Phase-Locked Loop Design and Devices Beyond Bulk CMOS

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    Phase-locked loop (PLLs) has been widely used in analog or mixed-signal integrated circuits. Since there is an increasing market for low noise and high speed devices, PLLs are being employed in communications. In this dissertation, we investigated phase noise, tuning range, jitter, and power performances in different architectures of PLL designs. More energy efficient devices such as memristor, graphene, transition metal di-chalcogenide (TMDC) materials and their respective transistors are introduced in the design phase-locked loop. Subsequently, we modeled phase noise of a CMOS phase-locked loop from the superposition of noises from its building blocks which comprises of a voltage-controlled oscillator, loop filter, frequency divider, phase-frequency detector, and the auxiliary input reference clock. Similarly, a linear time-invariant model that has additive noise sources in frequency domain is used to analyze the phase noise. The modeled phase noise results are further compared with the corresponding phase-locked loop designs in different n-well CMOS processes. With the scaling of CMOS technology and the increase of the electrical field, the problem of short channel effects (SCE) has become dominant, which causes decay in subthreshold slope (SS) and positive and negative shifts in the threshold voltages of nMOS and pMOS transistors, respectively. Various devices are proposed to continue extending Moore\u27s law and the roadmap in semiconductor industry. We employed tunnel field effect transistor owing to its better performance in terms of SS, leakage current, power consumption etc. Applying an appropriate bias voltage to the gate-source region of TFET causes the valence band to align with the conduction band and injecting the charge carriers. Similarly, under reverse bias, the two bands are misaligned and there is no injection of carriers. We implemented graphene TFET and MoS2 in PLL design and the results show improvements in phase noise, jitter, tuning range, and frequency of operation. In addition, the power consumption is greatly reduced due to the low supply voltage of tunnel field effect transistor

    New opportunities for photon storage and detection: an exploration of a high-efficiency optical quantum memory and the quantum capabilities of the human eye

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    The field of quantum information has grown in recent years, due to tremendous technological advancements toward quantum networking and quantum computation. Nevertheless, there is still a great need for creative research that explores possibilities for new capabilities. Particularly, we look towards quantum optics research to develop new ways of manipulating and detecting photons. Here, we discuss our efforts toward developing two separate quantum optics experiments that can provide great insight into the development of quantum devices. We begin by discussing our work to investigate the lower threshold of human vision and the eye's potential as a single-photon detector, using a custom-built single-photon source, and a novel two-alternative forced-choice experimental design. Our preliminary findings show promising data that support previous results found from a similar experiment using a somewhat different approach. We then discuss our second project, where we have developed a robust reconfigurable optical delay line quantum memory that compares favorably with competing methods. Our memory is capable of photon storage with an unprecedentedly high time-bandwidth product, high free-space transmission over the range of 10 ÎĽ\mus, and high fidelity. These attributes, plus the memory's capability for multi-mode storage, make this system a strong candidate for a critical component in the large-scale heterogeneous quantum networks we hope to see developed in the next ten years

    Formal Verification and In-Situ Test of Analog and Mixed-Signal Circuits

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    As CMOS technologies continuously scale down, designing robust analog and mixed-signal (AMS) circuits becomes increasingly difficult. Consequently, there are pressing needs for AMS design checking techniques, more specifically design verification and design for testability (DfT). The purpose of verification is to ensure that the performance of an AMS design meets its specification under process, voltage and temperature (PVT) variations and different working conditions, while DfT techniques aim at embedding testability into the design, by adding auxiliary circuitries for testing purpose. This dissertation focuses on improving the robustness of AMS designs in highly scaled technologies, by developing novel formal verification and in-situ test techniques. Compared with conventional AMS verification that relies more on heuristically chosen simulations, formal verification provides a mathematically rigorous way of checking the target design property. A formal verification framework is proposed that incorporates nonlinear SMT solving techniques and simulation exploration to efficiently verify the dynamic properties of AMS designs. A powerful Bayesian inference based technique is applied to dynamically tradeoff between the costs of simulation and nonlinear SMT. The feasibility and efficacy of the proposed methodology are demonstrated on the verification of lock time specification of a charge-pump PLL. The powerful and low-cost digital processing capabilities of today?s CMOS technologies are enabling many new in-situ test schemes in a mixed-signal environment. First, a novel two-level structure of GRO-PVDL is proposed for on-chip jitter testing of high-speed high-resolution applications with a gated ring oscillator (GRO) at the first level to provide a coarse measurement and a Vernier-style structure at the second level to further measure the residue from the first level with a fine resolution. With the feature of quantization noise shaping, an effective resolution of 0.8ps can be achieved using a 90nm CMOS technology. Second, the reconfigurability of recent all-digital PLL designs is exploited to provide in-situ output jitter test and diagnosis abilities under multiple parametric variations of key analog building blocks. As an extension, an in-situ test scheme is proposed to provide online testing for all-digital PLL based polar transmitters
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