Design of a low-power, small-area AEC-Q100-compliant SENT transmitter in signal conditioning IC for automotive pressure and temperature complex sensors in 180 Nm CMOS technology

Abstract

In this paper, a low-power and small-area Single Edge Nibble Transmission (SENT) transmitter design is proposed for automotive pressure and temperature complex sensor applications. To reduce the cost and size of the hardware, the pressure and temperature information is processed with a single integrated circuit (IC) and transmitted at the same time to the electronic control unit (ECU) through SENT. Due to its digital nature, it is immune to noise, has reduced sensitivity to electromagnetic interference (EMI), and generates low EMI. It requires only one PAD for its connectivity with ECU, and thus reduces the pin requirements, simplifies the connectivity, and minimizes the printed circuit board (PCB) complexity. The design is fully synthesizable, and independent of technology. The finite state machine-based approach is employed for area efficient implementation, and to translate the proposed architecture into hardware. The IC is fabricated in 1P6M 180 nm CMOS process with an area of (116 mu m x 116 mu m) and 4.314 K gates. The current consumption is 50 mu A from a 1.8 V supply with a total 90 mu W power. For compliance with AEC-Q100 for automotive reliability, a reverse and over voltage protection circuit is also implemented with human body model (HBM) electro-static discharge (ESD) of +6 kV, reverse voltage of 16 V to 0 V, over voltage of 8.2 V to 16 V, and fabricated area of 330 mu m x 680 mu m. The extensive testing, measurement, and simulation results prove that the design is fully compliant with SAE J2716 standard.