STMicroelectronics

The ST1S03 is a step-down DC-DC converter optimized for powering a low voltage digital core in HDD applications and, generally, to replace the high current linear solution when the power dissipation may cause a high heating of the application environment. It provides up to 1.5 A over an input voltage range of 3 V to 16 V. A high switching frequency (1.5 MHz) allows the use of tiny surface-mount components: as well as the resistor divider to set the output voltage value, only an inductor, a Schottky diode and two capacitors are required. Besides, a low output ripple is guaranteed by the current mode PWM topology and by the use of low ESR SMD ceramic capacitors. The device is thermal protected and current limited to prevent damages due to an accidental short-circuit. The ST1S03 device is available in a DFN6D package.

The ST1S14 is a step-down monolithic power switching regulator able to deliver up to 3 A DC current to the load depending on the application conditions. The high current level is also achieved thanks to a HSOP8 package with exposed frame, that allows to reduce the Rth(JA)down to approximately 40 °C/W. The output voltage can be set from 1.22 V. The device uses an internal N-channel DMOS transistor (with a typical RDS(on)of 200 mΩ) as the switching element to minimize the size of the external components. The internal oscillator fixes the switching frequency at 850 kHz. Power good open collector output validates the regulated output voltage as soon as it reaches the regulation. Pulse-by-pulse current limit offers an effective constant current short-circuit protection. Current foldback decreases overstress in a persistent short-circuit condition.