Protecting Automotive Circuits from the Elements Starts With These Solutions

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Anymore, our automobiles are like an integrated circuit on wheels. Passenger cars, trucks, buses, trains, and even motorcycles connect a wide variety of features and functions, including embedded controls, mobile media, and wireless options.

But this growing array of sensitive automotive electronics is susceptible to disturbances generated by the electrical system itself, by human interaction, or by load dump pulses.

Wide temperature swings and harsh environments brought on by corrosion, age, shock, and vibration can affect the quality of electrical connections and electrical insulation. It's also important to consider other electrically charged conditions that can affect circuitry—electrostatic discharges, power surges, short circuits, and power faults.

To combat and control these hazards, design engineers must develop solutions with lower clamping voltages and low capacitance. Fortunately, several solutions for circuit protection, including high-surge thyristors and electrostatic discharge protection diodes, are available.

Thyristors and ESD Protection Diodes Can Do the Trick

Littelfuse Px0S3N High Surge Current SIDACtor® Protection Thyristors are designed to protect sensitive equipment from overvoltage transients in hostile environments or exposed RS-485 data interfaces or AC and DC power supplies. In these components, both the switching voltage (VS) and on-state voltage (VT) are much lower than those of alternative Gas Discharge Tubes (GDTs), Metal Oxide Varistors (MOVs), and TVS Diodes. The Pxxx0S3N series features a fail short circuit when exposed to surges in excess of the rated 3000A 8/20μs. The thyristors' properties do not degrade after multiple surge events within their limits.

Toshiba DF Automotive ESD Protection Diodes are solutions to electrostatic discharge on 12V, 24V, and 28V CAN and LIN bus lines in vehicles. The diodes are AEC-Q101 qualified and intended for intervehicle communications using CAN and LIN bus protocols. The bidirectional diodes also feature low Vclamp and strong ESD immunity in addition to standard capacitances between 8pF and 10pF.

Vishay Semiconductors VCAN36A2-03G and VCAN36A2-03S ESD Protection Diodes are Bidirectional Symmetrical (BiSy) dual-line ESD protection diodes. They're optimized for CAN and FLEX-bus applications. These diodes also feature a maximum working voltage of ±33V (VCAN33A2-03G) and ±36V (VCAN36A2-03S) and a low 0.05µA leakage current.