1.5 A / 3.3 V step-down DC-DC converter demonstration board
Features
■ Adjustable current-mode PWM step-down DC-
DC converter
■ Output voltage, V
■ Output current, I
■ Internal compensation to eliminate additional
components
■ Pulse skipping for I
maintain the regulation with light loads
■ RoHS compliant
: 3.3 V
out
: 1.5 A
out
lower than 15 mA, to
out
STEVAL-ISA042V2
based on the ST1S03
Data brief
Description
The STEVAL-ISA042V2 demonstration board is a
step-down DC-DC converter optimized for
powering the low-voltage digital core in HDD
applications and, more generally, replacing the
high-current linear solution when the power
dissipation may cause excessive heating of the
application environment. It provides up to 1.5 A
over an input voltage range of 3 V to 16 V.
A high switching frequency (1.5 MHz) allows the
use of tiny surface-mounted components, as well
as the use of a resistor divider to set the output
voltage value. Only an inductor, a Schottky diode,
and two capacitors are required. 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 thermal
protected and current limited to prevent damage
due to accidental short-circuits.
It uses the ST1S03 device.
The ST1S03 is available in a DFN6 (3x3mm)
package.
STEVAL-ISA042V2
September 2010 Doc ID 18024 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Circuit schematic STEVAL-ISA042V1
1 Circuit schematic
Figure 1. STEVAL-ISA042V2 demonstration board schematic
!-6
2/4 Doc ID 18024 Rev 1
STEVAL-ISA042V1 Revision history
2 Revision history
Table 1. Document revision history
Date Revision Changes
28-Sep-2010 1 Initial release.
Doc ID 18024 Rev 1 3/4
STEVAL-ISA042V1
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4/4 Doc ID 18024 Rev 1
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