Transient Voltage Protection for Low-speed Interfaces and Power Supplies
Transient threats, such as electrostatic discharge (ESD), may compromise the operation of a bi-switching power supply, digital audio, or analog video port. Therefore, it’s important to incorporate transient voltage suppression at the outset when designing circuitry for these low-speed interfaces. Here’s a look at how to protect such interfaces (along with their power supplies) from transient voltage spikes.
Digital Audio Ports
Quick transient surges and ESD strikes can damage an audio codec’s internal components. A TVS diode (ESD protection diode) can solve this problem. This device can safely suppress as much as 40 A from a fast transient threat and an ESD strike of up to ±15 kV. It also responds fast to energy surges under 1 ns.
Video Ports
ESD and other transient strikes can compromise the reliability of a video port. To protect a video analog-to-digital converter against transient damage, you can add a 4-channel TVS diode array chip in the circuitry. The low current-leak component can safely block as much as 40 A electrically fast transient from entering the circuit.
Keypad Ports
The circuitry of keypads used in telecommunication, security access, display controls, and other consumer or industrial applications is vulnerable to ESD strikes. Designers can incorporate multi-layer varistors (MLVs) to block any such transient spikes from entering the keypad’s circuitry during activation. MLVs can suppress an energy spike of up to 2.5 J and current transient of up to 500 A. This versatile protective component has a broad operating temperature range (−40° C to 125° C).
Battery Pack Control Port
For battery pack protection, you can use a fast blow fuse to protect the controller IC from overcurrent. The circuit is also vulnerable to transient voltage spikes, which can be suppressed using a TVS diode array.
Power Source Circuitry
A fast-blow fuse is suitable for protecting an AC power source from potentially damaging current pulses. To protect the circuit from voltage spikes, you can add a Littelfuse MOV (metal oxide varistor). A blow glass body fuse would be appropriate for protecting an AC-DC power source.
DC Power Supplies
For 12V or 24 V DC power supply protection, consider incorporating a MOV or TVS diode. This will protect the circuit from voltage spikes. If you’re designing transient protection for a 48 VDC power supply or higher, use a TVS diode along with a ground line gas discharge tube. To optimize the reliability of your bi-switching power supply port or other low-speed interfaces, make sure to incorporate transient protection in the circuitry. For an extensive catalog of devices that you can use to build robust electrical circuits, visit the Allied Components International website. We build high-quality, cost-effective solutions for various industrial and consumer applications.
