Description
The ST1S03A is a step down DC-DC converter optimized for powering low-voltage digital core in HDD applications and, generally, to replace the high current linear solution when the power dissipation may cause an high heating of the application environment. It provides up to 1.5A over an input voltage range of 3V to 5.5V. An high switching frequency (1.5MHz) 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 E.S.R. SMD ceramic capacitors. The device is thermal protected and current limited to prevent damages due to accidental short circuit. The ST1S03A is available in DFN6 (3x3).

Features
■ Step-down current mode PWM (1.5MHz) DCDC converter
■ 2% DC output voltage tolerance
■ Internal soft start for start-up current limitation and power on delay of 50-100µs
■ Typical efficiency: > 85%
■ Inhibit function
■ 1.5A Output current capability
■ Not switching quiescent current: max 1.5mA over temperature range
■ Switch VDS: max 200mV @ ISW=750mA
■ Uses tiny capacitors and inductors
■ Available in DFN6 3x3 exposed pad