Silicon Carbide Fully Differential Amplifier Characterized Up to 500 °C

Abstract

Abstract-This paper presents a monolithic fully-differential amplifier implemented in a low-voltage 4H-SiC BJT technology. The circuit has been designed considering the variation of device parameters over a large temperature range. A base-current compensation technique has been applied to overcome the low input-resistance of the amplifier. The bare chip of the amplifier has been measured from 27 ºC to 500 ºC using a hot-chuck probe station. Its open-loop gain is 58 dB at 27 ºC, and monotonically decreases to 37 dB at 500 ºC. Its closed-loop gain reduction is around 5 dB over the investigated temperature range. The gain-bandwidth product drops from 2.8 MHz at 27 ºC to 1.3 MHz at 500 ºC with 470 pF off-chip compensation capacitors. A low total-harmonic-distortion of -58.4 dB at 27 ºC and -46.9 dB at 500 ºC is achieved due to the fully-differential implementation. A low input offset voltage of 0.5 mV at 27 ºC and 6.9 mV at 500 ºC is achieved without calibration. The relative high linearity and low offset demonstrate the potential of this technology to be further investigated for front-end sensor circuits in high-temperature applications.

Integrated Digital and Analog Circuit Blocks in a Scalable Silicon Carbide CMOS Technology

“…It is implemented by mesa etching in a complex epitaxial layer stack on top of a monocrystalline SiC wafer. In this technology, an OR/NOR gate [28], emitter-coupled logic (ECL)-based logic circuits [29], operational amplifier [30], differential amplifier [31], high current linear voltage regulator [32], and 8-bit DAC [33] were implemented and characterized up to 500 • C. Though BJTs and CMOS are the most popular flavors in silicon-based technologies, JFET [34], [35] and MESFET [36], [37] technologies have also been researched in the favor of stable operation at high temperatures. Although the MOSFET gate dielectric reliability has been a concern [38], [39], more recent work contradicts the poor reliability prediction and predict much longer lifetimes [40].…”

Design and comparative analysis of active-loaded differential amplifier using double-gate MOSFET

“…The output should also reject any common-mode signals. In superior designs, it may reduce input harmonic distortion [25]. A basic differential signal process is shown in Fig.…”

“…However, it is easily configurable and from Fig. 3(c), one can determine the expected output as [25][26][27]:…”

Lateral depletion-mode 4H-SiC n-channel junction field-effect transistors operational at 400 °C*

“…[5] Over the past decade, significant progress has already been made in the high-temperature devices and integrated circuits (ICs). Hightemperature ICs based on metal-oxide-semiconductor fieldeffect transistors (MOSFETs), [6,7] bipolar junction transistors (BJTs), [8,9] and junction field-effect transistors (JFETs) [10,11] have already been reported. High stability of threshold (V TH ) within a wide temperature range and being free from oxide reliability problem give JFET based ICs very high robustness for harsh environment applications.…”