2 A / 3.3 V high-efficiency synchronous buck converter
evaluation board based on the ST1S09
Features
■ Input voltage range: 2.7 V to 5.5 V
■ Output voltage: 3.3 V
■ Max I
■ High internal switching frequency: 1.5 MHz
■ Short-circuit protection
■ ST1S09 in the DFN6 3x3 package
Description
This evaluation board, based on the ST1S09
family of synchronous step-down DC-DC
converters, is optimized for powering all lowvoltage applications and, generally, replaces high
current linear solutions when power dissipation
may cause high heating of the application
environment.
out
: 2 A
STEVAL-ISA045V2
Data Brief
STEVAL-ISA045V2
It provides up to 2 A over an input voltage range
of 2.7 V to 5.5 V.
A high 1.5 MHz switching frequency allows the
use of tiny surface-mount components and in
addition to the resistor divider to set the output
voltage value, an inductor and two capacitors are
required.
A low output ripple is guaranteed by the current
mode PWM topology and by the use of low ESR
surface-mount ceramic capacitors.
The device is thermally protected and current
limited to prevent damage due to accidental shortcircuit.
The ST1S09 family is available in the DFN6 3x3
package.
March 2008 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Circuit schematic STEVAL-ISA045V2
1 Circuit schematic
Figure 1. Schematic
VIN_ A
5
Vin
R3
4
6
VIN_SW
PG
GND
ST1S09
VFVFB
SW
L1
3
Vouout
C1
2 1
R2
R1
C2
GND
2/4
STEVAL-ISA045V2 Revision history
2 Revision history
Table 1. Document revision history
Date Revision Changes
03-Mar-2008 1 Initial release.
3/4
STEVAL-ISA045V2
y
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