The SM712 from Semtech is a Transient Voltage Suppressor (TVS) diode designed specifically for protecting RS-485 interfaces in extended common-mode applications. It features an asymmetrical protection range of 12V to -7V, making it well-suited for multi-point data transmission standards like RS-485. With a peak pulse power of 400W for transient conditions and low capacitance, the SM712 ensures reliable protection against Electrostatic Discharge (ESD), Electrical Fast Transients (EFT), and lightning-induced transients.
Integrated into a compact SOT23 package, the SM712 replaces four discrete components by combining two 12V and two 7V TVS diodes, thereby reducing voltage overshoot due to trace inductance and minimizing stress on the protected transceiver. Its low clamping voltage further enhances the protection of sensitive electronic components. The device utilizes solid-state silicon avalanche technology, offering robust protection in a small footprint.
Diode
Transient Voltage Suppressor (TVS) diodes are essential components used to protect sensitive electronics from voltage spikes and surges. They are designed to rapidly clamp transient voltages to a safe level before they can damage the electronic circuitry. TVS diodes find applications across various sectors including telecommunications, computing, industrial, and consumer electronics.
When selecting a TVS diode, important considerations include the working voltage, peak pulse power, clamping voltage, package type, and capacitance. The working voltage should match or exceed the maximum operating voltage of the circuit to be protected. Peak pulse power indicates the diode's ability to absorb transient energy, while the clamping voltage determines the maximum voltage level the diode will allow before clamping. Lower capacitance values are preferred for high-speed data lines to minimize signal distortion.
The SM712 TVS diode, with its asymmetrical protection range, is specifically designed for RS-485 applications, providing robust protection against ESD, EFT, and lightning-induced transients. Its integrated design and low clamping voltage make it an ideal choice for protecting sensitive transceivers in extended common-mode applications.