ST1S09PUR

The ST1S09 is a step-down DC-DC converter optimized for powering low output voltage applications. It supplies a current in excess of 2 A over an input voltage range from 2.7 V to 6 V. A high PWM switching frequency (1.5 MHz) allows the use of tiny surface-mount components. Moreover, since the required synchronous rectifier is integrated, the number of the external components is reduced to minimum: a resistor divider, an inductor and two capacitors. The Power Good function continuously monitors the output voltage. An open drain Power Good flag is released when the output voltage is within regulation. In addition, 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 thermally protected and the output current limited to prevent damages due to accidental short circuit. The ST1S09 is available in the DFN6 (3 x 3 mm) package.

Key features

• 1.5 MHz fixed frequency PWM with current control mode
• 2 A output current capability
• Typical efficiency: >90%
• 2% DC output voltage tolerance
• Two versions available: power good or inhibit
• Integrated output over-voltage protection
• Non switching quiescent current: (typ) 1.5 mA over temperature range
• RDSON (typ) 100 mΩ
• Utilizes tiny capacitors and inductors
• Operating junction temp. -30 °C to 125 °C
• Available in DFN6 (3 x 3 mm) exposed pad