A 4-channel 12-bit high-voltage radiation-hardened digital-to-analog converter for low orbit satellite applications

This paper presents a circuit design and an implementation of a four-channel 12-bit digital-to-analog converter (DAC) with high-voltage operation and radiation-tolerant attribute using a specific CSMC H8312 0.5-μm Bi-CMOS technology to achieve the functionality across a wide-temperature range from -55 °C to 125 °C. In this paper, an R-2R resistor network is adopted in the DAC to provide necessary resistors matching which improves the DAC precision and linearity with both the global common centroid and local common centroid layout. Therefore, no additional, complicated digital calibration or laser-trimming are needed in this design. The experimental and measurement results show that the maximum frequency of the single-chip four-channel 12-bit R-2R ladder high-voltage radiation-tolerant DAC is 100 kHz, and the designed DAC achieves the maximum value of differential non-linearity of 0.18 LSB, and the maximum value of integral non-linearity of -0.53 LSB at 125 °C, which is close to the optimal DAC performance. The performance of the proposed DAC keeps constant over the whole temperature range from -55 °C to 125 °C. Furthermore, an enhanced radiation-hardened design has been demonstrated by utilizing a radiation chamber experimental setup. The fabricated radiation-tolerant DAC chipset occupies a die area of 7 mm x 7 mm in total including pads (core active area of 4 mm x 5 mm excluding pads) and consumes less than 525 mW, output voltage ranges from -10 to +10 V

An ultra wide temperature range R-2R based 8 bit D/A converter for 90nm CMOS technology

Digital-to-analog converters have a wide range of applications from converting stored digital/audio signals to data processing and to data acquisition systems. Another application area could be a supporting building block in either cooled or un-cooled Read-out integrated circuits (ROICs). For this aspect, the capability of ultra wide temperature range operation may prove useful providing freedom to the designer and the consumer. In this thesis, design of an 8-bit, fully binary R-2R based digital-to-analog converter is realized with 90nm CMOS technology to operate in a wide temperature range (-200°C to 120°C) to be used in an ongoing Digital Read-out Integrated Circuit (DROIC) for infrared (IR) imaging systems. UWT range of operation is obtained via a temperature compensated voltage reference generator circuit consisting of only MOSFETs. In order to aid the matching of the resistors, a common-centroid layout technique is applied to the resistor core of the circuit which eliminates the process gradients. TSMC's 90nm 1 poly, 9 metal Mixed – Signal RF technology and a power supply of 1.2V are used for this design. For accuracy, the best performance is obtained at the room temperature where the fastest operation is possible at cryogenic temperatures at the expense of precision. It has a DNL and INL of ±0.3LSB at room temperature and ±0.45LSB at 120°C. The DAC can operate up to 20MHz. The circuit dissipates only 0.43mW in full scale range at cryogenic temperatures where 1.1mW at room. It occupies a chip area of only 0.015mm2 [square millimetre]

Implémentation, ajustement laser et modélisation des convertisseurs numériques à analogique R2R

La conversion numérique à analogique -- Principales caractéristiques des CNA -- Algorithmes et architectures de conversion -- Techniques de linéarisation -- Le CNA R2R inversé -- Un CNA 14 bits ajusté au laser et fabriqué dans une technologie CMOS standard -- Puce -- Montage de test -- Notes et résultats de tests -- Une compensation améliorée pour les interrupteurs des CNA R2R inversés -- Modélisation des CNA R2R