P. Leroux

1-1-1 MASH

Two 1-1-1 MASH ΔΣ time-to-digital converters (TDCs) are presented in this paper. Third-order time domain noise-shaping has been adopted by the TDCs to achieve better than 6 ps resolution. Following a detailed analysis of the noise generation and propagation in the MASH ΔΣ structure, the first prototyping TDC has been realized in 0.13 μm CMOS technology. It achieves an ENOB of 11 bits and consumes 1.7 mW from a 1.2 V supply. In the second MASH TDC, a delay-line assisted calibration technique is introduced to mitigate the phase skew caused by the large comparator delay, which is the main limiting factor of the MASH TDCs resolution. The demonstrated TDC achieves an ENOB of 13 bits and a wide input range of 100 ns. This TDC shows a temperature coefficient of 176 ppm°C within a temperature range of -20 to 120°C. It consumes only 0.7 mW and occupies 0.08 mm2 area (core).

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The proton irradiation effects on n-MuGFET devices with three different geometries (single fin, wide fin and multiple fin) are studied. Also, the effect of tensile strain in the fin on the radiation behavior is investigated. A fundamental difference in the radiation behavior between the non-strained and the strained devices is found. The degradation of the strained devices is most affected by the mobility decrease of the backside transistor. The non-strained devices show a much lesser back gate mobility degradation. For these devices the creation of positive oxide traps is dominant. This shifts the onset of the back channel to lower gate voltages, inducing a transconductance increase at intermediate gate voltages. This effect is less pronounced for single fin MuGFETs. At higher gate voltage, the transconductance decreases for the strained and increases for the non-strained transistors.

Time-to-Digital Converters With 6 ps Resolution and Third-Order Noise-Shaping

A first assessment of the total dose behavior of bulk p-multiple-gate field-effect transistors (MuGFETs) is reported, and special attention is given to the effect of the fin width on the radiation behavior. It was found that the effect of radiation-induced traps in the shallow trench isolation is larger when the fin width decreases. This is in contrast to the total dose behavior of SOI MuGFETs.

Geometry and Strain Dependence of the Proton Radiation Behavior of MuGFET Devices

The radiation hard design of a 155 Mb/s, 0.7 mum CMOS driver for a vertical-cavity surface-emitting laser (VCSEL) is presented. The circuit features enhanced tolerance to radiation induced shifts in the device characteristics by employing a replica-based feedback mechanism. The layout was achieved using an in-house developed radiation hardened component library. At a low dose rate of 4.5 Gy/h or 450 rad/h, the output current remains constant up to at least 3.5 kGy. At a dose rate of 21 kGy/h, the output current of the driver drops by 10% at a dose of 3.5 MGy and breaks down completely at 5.5 MGy.

Influence of Fin Width on the Total Dose Behavior of p-Channel Bulk MuGFETs

Time-to-Digital Converters (TDCs) are key building blocks in time-based mixed-signal systems, used for the digitization of analog signals in time domain. A short survey on state-of-the-art TDCs is given. A novel multi-stage noise-shaping (MASH) delta-sigma <formula formulatype=inline><tex Notation=TeX>

Design and Assessment of a Circuit and Layout Level Radiation Hardened CMOS VCSEL Driver

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Design and Assessment of a 6 ps-Resolution Time-to-Digital Converter With 5 MGy Gamma-Dose Tolerance for LIDAR Application

</tex> </formula> TDC structure is proposed for applications in continuous-time pulsed time-of-flight (TOF) rangefinders for nuclear reactor remote sensing, which requires both high resolution and multi MGy gamma-dose radiation tolerance. The converter, implemented in 0.13 <formula formulatype=inline><tex Notation=TeX>

A 4.5 MGy TID-Tolerant CMOS Bandgap Reference Circuit Using a Dynamic Base Leakage Compensation Technique

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Design and Assessment of a High Gamma-Dose Tolerant VCSEL Driver wit Discrete SiGe HBT's

</tex></formula>, achieves a time resolution of 5.6 ps and an ENOB of 11 bits, when the oversampling ratio (OSR) is 250. The TDC core consumes only 1.7 mW and occupies an area of 0.11 <formula formulatype=inline> <tex Notation=TeX>

Influence of Back-Gate Bias and Process Conditions on the Gamma Degradation of the Transconductance of MuGFETs

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