A Monolithic 500°C D-Flip Flop Realized in Bipolar 4H-SiC TTL Technology

Abstract

This work presents the design, in-house fabrication, and electrical characterization of a monolithic medium scale integrated (MSI) D-type flip-flop (DFF). It consists of 65 n-p-n bipolar transistors and 49 integrated resistors. The monolithic bipolar DFF is realized using basic gates by employing the structured way of implementation, whereas the basic gates are implemented by employing the conventional transistor-transistor logic (TTL). The positive-edge-triggered DFF, with synchronous active-low reset is characterized in the temperature range of 25-500 °C. The circuit has been tested in two modes of operation; data input mode and clock divider. Non-monotonous temperature dependence is observed for the flip-flop propagation-delay clock-to-output (tPCQ), rise-time and fall-time; decreases with the temperature in the range 25 °C to 300 °C, while it increases in the range 300 °C to 500 °C. The transient response has also been measured at a clock frequency of 100 kHz. At T = 400 °C and VCC = 15 V, the DFF consumes minimum energy ≈ 234 nJ.