ST1S03
1.5A, 1.5 MHZ ADJUSTABLE,
STEP-DOWN SWITCHING REGULATOR IN DFN6
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STEP-DOWN CURRENT MODE PWM
(1.5MHz) DC-DC CONVERTER
2% DC OUTPUT VOLTAGE TOLERANCE
INTERNAL SOFT START FOR START-UP
CURRENT LIMITIATION AND POWER ON
DELAY OF 50-100µs
TYPICAL EFFICIENCY: > 70% OVER ALL
OPERATING CONDITIONS
1.5A OUTPUT CURRENT CAPABILITY
NOT SWITCHING QUIESCENT CURRENT:
MAX 2.5mA OVER TEMPERATURE RANGE
SWITCH V
DS
: MAX 350mV @ISW=750mA
USES TINY CAPACITORS AND INDUCTORS
AVAILABLE IN DFN 3x3 EXPOSED PAD
DFN6 (3x3)
DESCRIPTION
The ST1S03 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 16V. An high
Figure 1: Schematic Diagram
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 ST1S03 is
available in DFN6 package.
March 2005
Rev. 3
1/11
STMICROELECTRONICS [ STMICROELECTRONICS ]
