STMicroelectronics STNRG599 Resonant Half-Bridge Controller

Output voltage (or current) regulation is obtained by directly controlling the phase shift between the half-bridge voltage and the resonant tank current. This proprietary control method, called phase shift control (PSC), enhances dynamic behavior and input voltage ripple rejection. Additionally, it creates a control loop with reduced sensitivity to component tolerance in the LLC/LCC resonant tank. At light load, STNRG599 enters a controlled burst-mode operation, enabling intermittent converter operation. This feature reduces the average switching frequency and minimizes the open-load input power.

The STMicroelectronics STNRG599 is equipped with a full set of protection features. These features include hard-switch prevention and anti-capacitive protection, as well as 1st and 2nd level overcurrent protection, delayed shutdown, and a restart function based on pin DELAY (for user-programmable delayed shutdown upon overload with automatic restart). Overall, OCP1, OCP2, and functions based on pin DELAY provide reliable and robust management of conditions such as short-time overcurrent, continuous overload, and severe output short-circuit.

DC brown-out/in protection is not latched. It is implemented at the input pin LINE, with a constant hysteresis between brown-out and brown-in thresholds. The function prevents converter operation outside the selected DC input voltage range.