SmartClamp DrMOS adds cycle-by-cycle current limiting for AI servers

Alpha and Omega Semiconductor has introduced its SmartClamp protected DrMOS family, targeting the high peak-current behavior seen in AI servers, data centers, and high-end graphics cards. The company’s lead device in the line, the AOZ53228QI, is aimed at multiphase voltage regulator designs where current spikes can trigger hard failures in the power stage.

AOS says the SmartClamp family integrates high-accuracy Over Current Protection (OCP) and Negative Current Protection (NCP), with current limiting implemented directly in the DrMOS power stage instead of relying only on the controller. The goal is to reduce the time window where an overcurrent event can run away, particularly in conditions like inductor saturation.

The company points to the risk of protection delays in fast transients: it states that even a 50 ns OCP delay can cause a 30 A current runaway, which can damage the high-side MOSFET in these high di/dt scenarios. For engineers working on dense Vcore rails for CPUs and GPUs, that’s a practical reliability issue, not a theoretical one—once you’re operating near magnetic and silicon limits, “fast enough” protection becomes a design requirement.

SmartClamp’s protection approach includes cycle-by-cycle monitoring using an internal rising-edge current ramp to track inductor current in real time. AOS also describes “accurate positive and negative current limiting” intended to handle high slew rates, and says the parts are optimized for constant-on-time (COT) and fixed-frequency PWM controllers, as well as its AOS Advanced Transient Modulator (A2TM) multiphase controllers.

“By pairing these with our advanced controllers—such as the OVR16, OVR4-22, and Intel IMVP/AMD SVI3 compatible series—we offer a seamless, high-efficiency Vcore solution that gives designers peace of mind in high-density power applications,” said Zach Zhang, Power IC Marketing Director at AOS.

AOS lists “10% peak current accuracy” for the SmartClamp DrMOS family. The SmartClamp series is available “in production quantities” with a 12-week lead time. For the AOZ53228QI, AOS lists a unit price of $1.40 at 1,000-piece quantities. More information is available from Alpha and Omega Semiconductor.