139 research outputs found

    Dispositifs de protection contre les décharges électrostatiques pour les applications radio fréquences et millimétriques

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    Ces travaux s'inscrivent dans un contexte où les contraintes vis-à-vis des décharges électrostatiques sont de plus en plus fortes, les circuits de protection sont un problème récurrent pour les circuits fonctionnant à hautes fréquences. La capacité parasite des composants de protection limite fortement la transmission du signal et peut perturber fortement le fonctionnement normal d'un circuit. Les travaux présentés dans ce mémoire font suite à une volonté de fournir aux concepteurs de circuits fonctionnant aux fréquences millimétriques un circuit de protection robuste présentant de faibles pertes en transmission, avec des dimensions très petites et fonctionnant sur une très large bande de fréquences, allant du courant continu à 100 GHz. Pour cela, une étude approfondie des lignes de transmission et des composants de protection a été réalisée à l'aide de simulations électromagnétiques et de circuits. Placés et fragmentées le long de ces lignes de transmission, les composants de protection ont été optimisés afin de perturber le moins possible la transmission du signal, tout en gardant une forte robustesse face aux décharges électrostatiques. Cette stratégie de protection a été réalisée et validée en technologies CMOS avancées par des mesures fréquentielles, électriques et de courant de fuite.Advanced CMOS technologies provide an easier way to realize radio-frequency integrated circuits (RFICs). However, the lithography dimension shrink make electrostatic discharges (ESD) issues become more significant. Specific ESD protection devices are embedded in RFICs to avoid any damage. Unfortunately, ESD protections parasitic capacitance limits the operating bandwidth of RFICs. ESD protection size dimensions are also an issue for the protection of RFICs, in order to avoid a significant increase in production costs. This work focuses on a broadband ESD solution (DC-100 GHz) able to be implemented in an I/O pad to protect RFICs in advanced CMOS technologies. Thanks to the signal transmission properties of coplanar / microstrip lines, a broadband ESD solution is achieved by implementing ESD components under a transmission line. The silicon proved structure is broadband; it can be used in any RF circuits and fulfill ESD target. The physical dimensions also enable easy on-chip integration.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

    Analysis and design of a high power millimeter-wave power amplifier in a SiGe BiCMOS technology

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    Our current society is characterized by an ever increasing need for bandwidth leading towards the exploration of new parts of the electromagnetic spectrum for data transmission. This results in a rising interest and development of millimeter-wave (mm-wave) circuits which hold the promise of short range multi-gigabit wireless transmissions at 60GHz. These relatively new applications are to co-exist with more established mm-wave consumer products including satellite systems in the Ka-band (26.5GHz - 40GHz) allowing e.g.: video broadcasting, voice over IP (VoIP), internet acces to remote areas, ... Both need significant linear power amplification due to the high attenuation typical for this part of the spectrum, however, satellite systems demand a saturated output power which is easily an order of magnitude larger (output powers in excess of 30dBm / 1W). Monolithic microwave integrated circuits (MMICs) employing III-V chip technologies, e.g.: gallium arsenide (GaAs), gallium nitride (GaN), have historically been the preferred choice to implement efficient mm-wave power amplifiers (PA) with a high saturated output power (>30dBm). To further increase the commercial viability of consumer products in this market segment a low manufacturing cost for the power amplifier, together with the possible integration of additional functions, is highly desirable. These features are the strongpoint of silicon based chip technologies like CMOS and SiGe BiCMOS. However, these technologies have a breakdown voltage typically below 2V for nodes capable of millimeter-wave applications while III-V transistors with equivalent frequency performance demonstrate breakdown voltages in excess of 8V. Because of this, output powers of CMOS and SiGe BiCMOS Ka-band power amplifiers rarely exceed 20dBm which poses the main hurdle for using these technologies in satellite communication (SATCOM). To overcome the limited output power of a single amplifying cell in a silicon technology, caused by the low breakdown voltage, multiple power amplifiers cells need to have their output power effectively combined on-chip. This requires the on-chip integration of high-Q passives within a relative small area to realize both the impedance transformation, to create the optimal load impedance for the different amplifier cells, and implement an efficient on-chip power combination network. Compared to III-V technologies this is again a challenge due to the use of a silicon substrate which introduces higher losses. Once a large enough on-chip output power is created, the issue of launching this signal to the outside world remains. Moreover, due to the limited efficiency of mm-wave PAs, the generated on-chip heat will increase when larger output power are required. This means a chipto-board interface with a low thermal resistance and a low loss electrical connection needs to be devised. Proof of the viability of silicon as a serious candidate for the integration of medium and high power Ka-band amplifiers will only be delivered by long term research and the actual creation of such an amplifier. In this context, the initial goal for the presented work is proposed. This consists of the creation of a power amplifier with a saturated output power above 24dBm (preferably 27dBm), a gain larger than 20dB and an efficiency in excess of 10% (preferably 15%). These specifications where conceived with the precondition of using a 250nm SiGe BiCMOS technology (IHP’s SG25H3) with an fT of 110GHz and a collector to emitter breakdown voltage in open base conditions (BVCEO) of 2.3V. The use of this technology is a significant challenge due to the limited speed, rule of thumb is to have at least one fifth of the fT as the operating frequency, which reflects in the attainable power added efficiency (PAE). On the other hand, proving the possible implementation in this “older” technology shows great potential towards the future integration in a fast technology (e.g.: IHP’s SG13G2, ft =300GHz). Next to issues caused by limitations of the chip technology, the proposed specifications allows to identify generic difficulties with high power silicon PA design, e.g.: design of efficient on-chip power combiners, thermal management, single-ended to differential conversion, ... As this work is of an academic nature the intention of this design was to leave the beaten track and explore alternative topologies. This has led to the adoption of a driver stage using translinear loops for biasing and a transformer-type Wilkinson power combiner previously only used in cable television (CATV) applications. Although the power combiner showed 2dB more loss than expected due to higher than expected substrate losses, both topologies show promise for further integration. Furthermore, an in-depth analysis was performed on the output stage which uses positive feedback to increase its gain. The entire design consists of a four-way power combining class AB power amplifier together with test structures of which the performance was verified by means of probing. Due to the previously mentioned higher than expected loss in the on-chip power combiner, the total output power and power added efficiency (PAE) was 2dB lower than expected from simulations. The result is a saturated output power at 32GHz of 24.1dBm with a PAE of 7.2% and a small signal gain of 25dB. This demonstrates the capability of SiGe BiCMOS to implement PA’s for medium-power mm-wave applications. Moreover, to the best of the author’s knowledge, this PA achieves the second highest saturated output power when comparing SiGe BiCMOS PA’s with center frequency in or close to the Ka-band. The 1dB compression point of this amplifier lies at 22.7dBm which is close to saturated output power and results in a low spectral regrowth when compared to commercial GaAs PA’s (compared with 2MBaud 16QAM input signal at 10dB back-off). Many possible improvements to this design remain. The most important would be the re-design of the on-chip power combiner, possibly with a floating ground shield, to reduce the losses and increase the total output power and PAE. Also the porting of the design to a faster chip technology might result in a considerable increase of the output stage efficiency at the cost of needing to combine more amplifier cells. The transition to a faster chip technology would additionally allow to use this design for alternative mm-wave applications like automotive radar at 79GHz andWiGig at 60GHz

    Avionics system design for high energy fields: A guide for the designer and airworthiness specialist

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    Because of the significant differences in transient susceptibility, the use of digital electronics in flight critical systems, and the reduced shielding effects of composite materials, there is a definite need to define pracitices which will minimize electromagnetic susceptibility, to investigate the operational environment, and to develop appropriate testing methods for flight critical systems. The design practices which will lead to reduced electromagnetic susceptibility of avionics systems in high energy fields is described. The levels of emission that can be anticipated from generic digital devices. It is assumed that as data processing equipment becomes an ever larger part of the avionics package, the construction methods of the data processing industry will increasingly carry over into aircraft. In Appendix 1 tentative revisions to RTCA DO-160B, Environmental Conditions and Test Procedures for Airborne Equipment, are presented. These revisions are intended to safeguard flight critical systems from the effects of high energy electromagnetic fields. A very extensive and useful bibliography on both electromagnetic compatibility and avionics issues is included

    Integrated Circuit Design for Hybrid Optoelectronic Interconnects

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    This dissertation focuses on high-speed circuit design for the integration of hybrid optoelectronic interconnects. It bridges the gap between electronic circuit design and optical device design by seamlessly incorporating the compact Verilog-A model for optical components into the SPICE-like simulation environment, such as the Cadence design tool. Optical components fabricated in the IME 130nm SOI CMOS process are characterized. Corresponding compact Verilog-A models for Mach-Zehnder modulator (MZM) device are developed. With this approach, electro-optical co-design and hybrid simulation are made possible. The developed optical models are used for analyzing the system-level specifications of an MZM based optoelectronic transceiver link. Link power budgets for NRZ, PAM-4 and PAM-8 signaling modulations are simulated at system-level. The optimal transmitter extinction ratio (ER) is derived based on the required receiver\u27s minimum optical modulation amplitude (OMA). A limiting receiver is fabricated in the IBM 130 nm CMOS process. By side- by-side wire-bonding to a commercial high-speed InGaAs/InP PIN photodiode, we demonstrate that the hybrid optoelectronic limiting receiver can achieve the bit error rate (BER) of 10-12 with a -6.7 dBm sensitivity at 4 Gb/s. A full-rate, 4-channel 29-1 length parallel PRBS is fabricated in the IBM 130 nm SiGe BiCMOS process. Together with a 10 GHz phase locked loop (PLL) designed from system architecture to transistor level design, the PRBS is demonstrated operating at more than 10 Gb/s. Lessons learned from high-speed PCB design, dealing with signal integrity issue regarding to the PCB transmission line are summarized

    Design of reliable and energy-efficient high-speed interface circuits

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    The data-rate demand in high-speed interface circuits increases exponentially every year. High-speed I/Os are better implemented in advanced process technologies for lower-power systems, with the advantages of improved driving capability of the transistors and reduced parasitic capacitance. However, advanced technologies are not necessarily advantageous in terms of device reliability; in particular device failure from electrostatic discharge (ESD) becomes more likely in nano-scale process nodes. In order to secure ESD resiliency, the size of ESD devices on I/O pads should be sufficiently large, which may potentially reduce I/O speed. These two conflicting requirements in high-speed I/O design sometimes require sacrifice to one of the two properties. In this dissertation, three different approaches are proposed to achieve reliable and energy-efficient interface circuits. As the first approach, a novel ESD self-protection scheme to utilize “adaptive active bias conditioning” is proposed to reduce voltage stress on the vulnerable transistors, thereby reducing the burden on ESD protection devices. The second approach is to cancel out effective parasitic capacitance from ESD devices by the T-coil network. Voltage overshoot generated by magnetic coupling of the T-coil network can be suppressed by the proposed “inductance halving” technique, which reduces mutual inductance during ESD. The last approach employs system-level knowledge in the design of an ADC-based receiver for high intersymbol interference (ISI) channels. As a system-level performance metric, bit-error rate (BER) is adopted to mitigate a bit-resolution requirement in “BER-optimal ADC”, which can lead to 2× power-efficiency in the flash ADC and achieve a better BER performance

    Design Of Low-capacitance And High-speed Electrostatic Discharge (esd) Devices For Low-voltage Protection Applications

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    Electrostatic discharge (ESD) is defined as the transfer of charge between bodies at different potentials. The electrostatic discharge induced integrated circuit damages occur throughout the whole life of a product from the manufacturing, testing, shipping, handing, to end user operating stages. This is particularly true as microelectronics technology continues shrink to nano-metric dimensions. The ESD related failures is a major IC reliability concern and results in a loss of millions dollars to the semiconductor industry each year. Several ESD stress models and test methods have been developed to reproduce the real world ESD discharge events and quantify the sensitivity of ESD protection structures. The basic ESD models are: Human body model (HBM), Machine model (MM), and Charged device model (CDM). To avoid or reduce the IC failure due to ESD, the on-chip ESD protection structures and schemes have been implemented to discharge ESD current and clamp overstress voltage under different ESD stress events. Because of its simple structure and good performance, the junction diode is widely used in on-chip ESD protection applications. This is particularly true for ESD protection of lowvoltage ICs where a relatively low trigger voltage for the ESD protection device is required. However, when the diode operates under the ESD stress, its current density and temperature are far beyond the normal conditions and the device is in danger of being damaged. For the design of effective ESD protection solution, the ESD robustness and low parasitic capacitance are two major concerns. The ESD robustness is usually defined after the failure current It2 and on-state resistance Ron. The transmission line pulsing (TLP) measurement is a very effective tool for evaluating the ESD robustness of a circuit or single element. This is particularly helpful in iv characterizing the effect of HBM stress where the ESD-induced damages are more likely due to thermal failures. Two types of diodes with different anode/cathode isolation technologies will be investigated for their ESD performance: one with a LOCOS (Local Oxidation of Silicon) oxide isolation called the LOCOS-bound diode, the other with a polysilicon gate isolation called the polysilicon-bound diode. We first examine the ESD performance of the LOCOS-bound diode. The effects of different diode geometries, metal connection patterns, dimensions and junction configurations on the ESD robustness and parasitic capacitance are investigated experimentally. The devices considered are N+/P-well junction LOCOS-bound diodes having different device widths, lengths and finger numbers, but the approach applies generally to the P+/N-well junction diode as well. The results provide useful insights into optimizing the diode for robust HBM ESD protection applications. Then, the current carrying and voltage clamping capabilities of LOCOS- and polysiliconbound diodes are compared and investigated based on both TCAD simulation and experimental results. Comparison of these capabilities leads to the conclusion that the polysilicon-bound diode is more suited for ESD protection applications due to its higher performance. The effects of polysilicon-bound diode’s design parameters, including the device width, anode/cathode length, finger number, poly-gate length, terminal connection and metal topology, on the ESD robustness are studied. Two figures of merits, FOM_It2 and FOM_Ron, are developed to better assess the effects of different parameters on polysilicon-bound diode’s overall ESD performance. As latest generation package styles such as mBGAs, SOTs, SC70s, and CSPs are going to the millimeter-range dimensions, they are often effectively too small for people to handle with fingers. The recent industry data indicates the charged device model (CDM) ESD event becomes v increasingly important in today’s manufacturing environment and packaging technology. This event generates highly destructive pulses with a very short rise time and very small duration. TLP has been modified to probe CDM ESD protection effectiveness. The pulse width was reduced to the range of 1-10 ns to mimic the very fast transient of the CDM pulses. Such a very fast TLP (VFTLP) testing has been used frequently for CDM ESD characterization. The overshoot voltage and turn-on time are two key considerations for designing the CDM ESD protection devices. A relatively high overshoot voltage can cause failure of the protection devices as well as the protected devices, and a relatively long turn-on time may not switch on the protection device fast enough to effectively protect the core circuit against the CDM stress. The overshoot voltage and turn-on time of an ESD protection device can be observed and extracted from the voltage versus time waveforms measured from the VFTLP testing. Transient behaviors of polysilicon-bound diodes subject to pulses generated by the VFTLP tester are characterized for fast ESD events such as the charged device model. The effects of changing devices’ dimension parameters on the transient behaviors and on the overshoot voltage and turn-on time are studied. The correlation between the diode failure and poly-gate configuration under the VFTLP stress is also investigated. Silicon-controlled rectifier (SCR) is another widely used ESD device for protecting the I/O pins and power supply rails of integrated circuits. Multiple fingers are often needed to achieve optimal ESD protection performance, but the uniformity of finger triggering and current flow is always a concern for multi-finger SCR devices operating under the post-snapback region. Without a proper understanding of the finger turn-on mechanism, design and realization of robust SCRs for ESD protection applications are not possible. Two two-finger SCRs with different combinations of anode/cathode regions are considered, and their finger turn-on vi uniformities are analyzed based on the I-V characteristics obtained from the transmission line pulsing (TLP) tester. The dV/dt effect of pulses with different rise times on the finger turn-on behavior of the SCRs are also investigated experimentally. In this work, unless noted otherwise, all the measurements are conducted using the Barth 4002 transmission line pulsing (TLP) and Barth 4012 very-fast transmission line pulsing (VFTLP) testers

    Custom Integrated Circuit Design for Portable Ultrasound Scanners

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    Application and design manual for High Performance RF products

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