Voltage-clamp module protects ultra-low-voltage designs

Advanced Linear Devices Inc. (ALD) has claimed an industry first low-power, low-voltage, high-precision voltage-clamp module to protect mission-critical systems at 5 V and below. The SABMBOVP clamping solution targets mission-critical applications deployed in business, safety, and security products including industrial IoT (IIoT), banking, transportation, and power systems.

Low-voltage circuits are at risk of overvoltage failure from transient voltage spikes from sudden load changes or high transient energy levels, which can damage systems. These low-power designs can now be protected by using an overvoltage protection circuit or a voltage clamp, which is a circuit designed to limit the output voltage to a specific range, said ALD.

Based on ALD’s proprietary EPAD technology for low-voltage, low-power, high-precision linear applications, the SABMBOVP overvoltage protection (OVP) circuit board series protects from overvoltage by using very low-voltage precision enhancement-mode MOSFETs to improve the clamping function. Each ALD board provides two identical clamp-voltage channels. They can be used as independent clamps, or they may be stacked to double the basic clamp threshold voltage, said ALD.

The clamp voltages on a single device will be identical. However, different boards with different clamp voltages can be added to the stack for different combinations of clamp voltages.

When compared to Zener diode options, both the SABMBOVP and the Zener diode monitor the input voltage and control the external transistor switch’s gate without affecting the load circuit’s operation. The difference is that the overvoltage protection circuit disconnects the load during the transient event, said ALD, whereas the voltage clamp continues to power the load but clamps the voltage at a “not to exceed” predetermined voltage.

In addition, the SABMBOVP, at <100 nA max, has a significantly lower quiescent current than the low-voltage Zener, said ALD. It also has a better voltage-versus-current (I-V) characteristic, more precise voltages, faster response time at <100 ns, and a better surge current handling capability of >100 mA.

The ALD OVP clamps are self-contained and do not require additional components, such as a resistor divider, amplifier buffering circuits, and voltage regulator circuits, as required by Zener diodes. This reduces complexity and lowers power consumption, said the company.

The SABMBOVP family is available fully tested and off-the-shelf. The parts are currently in stock at Mouser or Digi-Key with prices starting at $12.81 to $20.54 each. Download the datasheet PDF here.