The Micrel MIC28510 is an adjustable–frequency, synchronous buck regulator featuring unique adaptive on– time control architecture. The MIC28510 operates over an input supply range of 4.5V to 75V and provides a regulated output of up to 4A of output current. The output voltage is adjustable down to 0.8V with a guaranteed accuracy of ±1%. Micrel’s Hyper Speed Control architecture allows for ultra– fast transient response while reducing the output capacitance and also makes (High VIN) / (Low VOUT) operation possible. This adaptive tON ripple control architecture combines the advantages of fixed–frequency operation and fast transient response in a single device. The MIC28510 offers a full suite of protection features to ensure protection of the IC during fault conditions. These include undervoltage lockout to ensure proper operation under power–sag conditions, internal soft–start to reduce inrush current, foldback current limit, “hiccup” mode shortcircuit protection, and thermal shutdown.