English
Language : 

STEVAL-ISA044V5 Datasheet, PDF (1/4 Pages) STMicroelectronics – Inhibit pin available
STEVAL-ISA044V5
3 A synchronous 900 kHz step-down DC-DC converter
with inhibit function based on the ST1S10 (Power SO-8)
Data brief
Features
■ Input voltage range: 2.5 V to 18.0 V
■ Max IOUT : 3 A
■ High internal switching frequency : 900 kHz
■ PWM mode operation with a fixed frequency or
synchronized to an external frequency
between 400 kHz and 1.2 MHz
■ Inhibit pin available
■ Quiescent current : < 6 µA in inhibit state
■ RoHS compliant
Description
The STEVAL-ISA044V5 is a demonstration board
based on the ST1S10 device assembled in a
Power SO-8 ePad package. The ST1S10 is a
step-down DC-DC converter with the inhibit
function optimized for powering high voltages in
LCD applications and low voltages in digital-core
HDD applications. It replaces the high-current
linear solution when high power dissipation is an
issue.
It provides up to 3 A over an input voltage range
of 2.5 V to 18.0 V, and synchronous rectification
removes the need for an external Schottky diode.
A high internal switching frequency (900 kHz)
allows for the use of tiny surface-mount
components, as well as a resistor divider to set
the output voltage value. Only an inductor and 3
capacitors are required.
The current-mode PWM architecture and stable
operation with low-ESR SMD ceramic capacitors
result in low output ripple. To maximize power
conversion efficiency in light load, the regulator
can work in burst mode automatically. The device
can operate in PWM mode with a fixed frequency
or synchronized to an external frequency. It
switches at a frequency of 900 kHz when the
SYNC pin is connected to ground or a fixed
voltage (less than 5.5 V), and can synchronize the
switching frequency between 400 kHz to 1.2 MHz
from an external clock applied to the SYNC pin.
A thermal shutdown circuit is integrated and
activates at 150 °C. Cycle-by-cycle current
limitation provides protection against shorted
outputs. The quiescent current is less than 6 µA
in the inhibit state.
October 2011
Doc ID 022348 Rev 1
For further information contact your local STMicroelectronics sales office.
1/4
www.st.com
4