Development of a digital input interface IC for automotive electronic control unit

An input interface IC to protect an LSI (such as a microcomputer used in an electronic control unit) from noise, surge, and high-power radio waves occurring at its input line has been developed. This IC has six input-output pairs. Filtering high-power radio waves, radio frequency surge, etc., is the main function of the IC. The IC also includes a level shifter which shifts battery voltage level (12 V) down to LSI level (5 V). This IC needs only one external resistor for each input. The ability to filter various surges and noises is superior than that of conventional input circuit. This IC has a level shift function and input current capacity of more than 1 mA without additional discrete components except for only one resistor/channel. Compared with conventional input circuits consisting of discrete components such as resistors, capacitors, and diodes, etc., this input interface IC offers the advantages of small size and high reliability of the entire electronic control unit.<>