Usually, when an high heating of the application environment is occurred due to the power dissipation, we use high current linear solution to solve that problem. But, we can solve that problem using Adjustable 1.5A Step Down 1.5 MHz Switching Regulator circuit. This circuit use ST1S03 step down DC-DC converter. The ST1S03 can also used for powering low-voltage digital core in HDD application. Here is the circuit:

Adjustable 1.5A Step Down 1.5 MHz Switching Regulator circuit schematic

The ST1S03 can gives up to 1.5A with input voltage range of 3V to 16V. This circuit can use tiny surface-mount components due to an high switching frequency (1.5MHz). To set the output voltage value, this circuit uses resistor divider. The components thoose are needed to build resistor divider are two capacitor, a schottky diode and an inductor.

This circuit has a low output ripple because of the use of low ESR SMD ceramic capacitors and the current mode PWM topology. To prevent damage which is caused by accidental short circuit, this circuit has current limitation and thermal protection. [Source: STMicroelectronics Application Note]