Mixed Signal Power IC for Automotive Electronics

Many ICs are used in various electronic components in automotive applications, such as ECUs (electronic control units) and smart actuators. Automotive ICs required the following features: (1) high integration of analog, digital and output devices; (2) high breakdown voltage for analog devices standing the battery voltage; (3) highly accurate control for analog circuits; (4) susceptibility under harsh operating conditions, such as high ambient temperature and high humidity; and (5) high surge immunity such as ESD (electrostatic discharge) robustness. To meet these requirements, we developed analog and output devices with improved surge endurance based on SOI wafer and trench-dielectric-isolation technologies.

Analog circuit applications, especially accurate power management or high-precision solenoid driving, demands stable temperature-compensated output. Load dump and battery-jumping also needs high voltage protection and high noise immunity for these devices. In this process bipolar transistors and thin film resistors are prepared for the circuit design. The bipolar transistors have high current drive capability and ESD robustness through an optimum cell design, comprising a special base, emitter and collector diffusion layer. The thin film resistor is composed of CrSiN and has characteristics of substantial zero temperature dependence and regulation by laser trimming, enabling very stable and precise analog output over a wide temperature range. The intelligent power IC developed in this research provides all of the features mentioned above and can be applied to various kinds of ECUs and smart actuators with high reliability at lower cost.