ST1S09 Datasheet, PDF (1/18 Pages) STMicroelectronics – 2A, 1.5 MHz PWM step-down switching regulator with synchronous rectification

ST1S09
2A, 1.5 MHz PWM step-down switching regulator
with synchronous rectification
Features
■ 1.5MHz fixed frequency PWM with current
control mode
■ 2A 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) 1.5mA
over temperature range
■ R_DSON (typ) 100mΩ
■ Utilizes tiny capacitors and inductors
■ Operating junction temp. -30°C to 125°C
■ Available in DFN6 3x3mm exposed pad
Description
The ST1S09 is a step-down DC-DC converter
optimized for powering low output voltage
applications. It supplies a current in excess of 2A
over an input voltage range from 2.7V to 6V.
A high PWM switching frequency (1.5MHz) allows
the use of tiny surface-mount components.
DFN6 (3x3mm)
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 E.S.R. 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 3x3mm package.
Table 1. Devices summary
Order codes
ST1S09PU
ST1S09APU ⁽¹⁾
ST1S09IPU
1. Available on request.
July 2007
Packaging
ST1S09PUR
ST1S09APUR
ST1S09IPUR
Rev. 2
Package
DFN6D (3x3 mm)
DFN6D (3x3 mm)
DFN6D (3x3 mm)
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