High Temperature Data Converters in Silicon Carbide CMOS

This paper presents an 8-b digital to analog converter (DAC) and 8-b analog to digital converter (ADC) for high-temperature applications. The pair of data converters were designed in a 1.2--m silicon carbide CMOS process and have been tested from 25 °C to 400 °C. At 400 °C, the DAC has a maximum differential nonlinearity (DNL) and integral nonlinearity (INL) error of 1.2 least significant bit (LSB) and 2.7 LSB, respectively, while the offset and the gain error are 5.9 and 2.7 LSB. The ADC has a maximum DNL and INL error of 3.6 and -3 LSB, respectively, while the offset error is -7 LSB and the gain error is 2.6 LSB. The ADC has an SNDR = 32.15 dB and effective number of bits = 5.05 b at 300 °C. The DAC is the first of its kind in silicon carbide CMOS, while the ADC is the first reported at temperatures over 300 °C.