| 1. |
- Hedayati, Raheleh, et al.
(author)
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A 500 degrees C 8-b Digital-to-Analog Converter in Silicon Carbide Bipolar Technology
- 2016
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In: IEEE Transactions on Electron Devices. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9383 .- 1557-9646. ; 63:9, s. 3445-3450
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Journal article (peer-reviewed)abstract
- High-temperature integrated circuits provide important sensing and controlling functionality in extreme environments. Silicon carbide bipolar technology can operate beyond 500 degrees C and has shown stable operation in both digital and analog circuit applications. This paper demonstrates an 8-b digital-to-analog converter (DAC). The DAC is realized in a current steering R-2R configuration. High-gain Darlington current switches are used to ensure ideal switching at 500 degrees C. The measured differential nonlinearity (DNL) and integral nonlinearity (INL) at 25 degrees C are 0.79 and 1.01 LSB, respectively, while at 500 degrees C, the DNL and INL are 4.7 and 2.5 LSB, respectively. In addition, the DAC achieves 53.6 and 40.6 dBc of spurious free dynamic range at 25 degrees C and 500 degrees C, respectively.
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| 2. |
- Hedayati, Raheleh, et al.
(author)
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Material aspects of wide temperature range amplifier design in SiC bipolar technologies
- 2016
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In: Journal of Materials Research. - : Cambridge University Press. - 0884-2914 .- 2044-5326. ; 31:19, s. 2928-2935
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Journal article (peer-reviewed)abstract
- Silicon carbide (SiC) is the main semiconductor alternative for low loss high voltage devices. The wide energy band gap also makes it suitable for extreme environment electronics, including very high temperatures. Operating integrated electronics at 500-600 °C poses several materials challenges. However, once electronics is available for these high temperatures, the added challenge is designing integrated circuits capable of operating in the entire range from room temperature to 500 °C. Circuit designers have to take into account parameter variations of resistors and transistors, and models are needed for several temperatures. A common circuit design technique to manage parameter variations between different transistors, without wide temperature variations, is to use negative feedback in amplifier circuits. In this paper we show that this design technique is also useful for adapting to temperature changes during operation. Two different amplifier designs in SiC are measured and simulated from room temperature up to 500 °C.
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| 3. |
- Hedayati, Raheleh, et al.
(author)
-
Wide Temperature Range Integrated Amplifier in Bipolar 4H-SiC Technology
- 2016
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In: 2016 46TH EUROPEAN SOLID-STATE DEVICE RESEARCH CONFERENCE (ESSDERC). - : IEEE. - 9781509029693 ; , s. 198-201
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Conference paper (peer-reviewed)abstract
- This paper presents a high temperature integrated amplifier implemented in bipolar 4H-SiC technology. A 40 dB negative feedback voltage amplifier has been designed using the structured design method to overcome the temperature variation of device parameters. The amplifier performance degrades as the temperature increases from room temperature up to 500 degrees C. The measured gain is reduced from 39 dB at room temperature to 34 dB at 500 degrees C, and the 3-dB bandwidth decreases from 195 kHz to 100 kHz. The measured power-supply-rejection-ratio (PSRR) is reduced from -78 dB to -62 dB, while the output voltage swing decreases from 8 V to 7 V.
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| 4. |
- Hedayati, Raheleh, et al.
(author)
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Wide Temperature Range Integrated Bandgap Voltage References in 4H–SiC
- 2016
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In: IEEE Electron Device Letters. - : IEEE. - 0741-3106 .- 1558-0563. ; 37:2, s. 146-149
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Journal article (peer-reviewed)abstract
- Three fully integrated bandgap voltage references (BGVRs) have been demonstrated in a 4H-SiC bipolar technology. The circuits have been characterized over a wide temperature range from 25 degrees C to 500 degrees C. The three BGVRs are functional and exhibit 46 ppm/degrees C, 131 ppm/degrees C, and 120 ppm/degrees C output voltage variations from 25 degrees C up to 500 degrees C. This letter shows that SiC bipolar BGVRs are capable of providing stable voltage references over a wide temperature range.
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