Multi-mode flyback regulator cuts standby power and eliminates audible noise
To enable efficient flyback supplies with no-load power below 30mW for compact home appliance designs, the Monolithic Power Systems HF600-40 integrates a 700V MOSFET and burst mode.
The HF600-40 is an integrated multi-mode flyback regulator designed for high-performance, high-efficiency offline power supplies. It supports continuous conduction mode (CCM) and quasi-resonant mode (QR), giving designers flexibility to optimize for load range, acoustic performance, and efficiency.
As a secondary-side regulation (SSR) based primary regulator, the HF600-40 is intended to work with secondary-side feedback circuitry. The converter integrates a high-voltage start-up circuit and uses burst mode at light load, enabling extremely low standby consumption, with the no-load power described as below 30mW. This makes it a strong fit for home appliance auxiliary supplies and always-on rails that must meet stringent standby targets.
To address one of the persistent pain points in QR flyback supplies, HF600-40 implements a patented valley lock technique that restrains valley jumping, helping to prevent audible noise. In addition, the regulator adopts multiple pulse-frequency modulation (PFM) modes based on input voltage, which increases output power capability in wide input designs. Frequency jittering is also included to help spread emissions and reduce the electromagnetic interference (EMI) signature.