Data brief
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July 2009 Doc ID 15975 Rev 1 1/4
4
STEVAL-ISA048V2
1 A adjustable Vout PWM synchronous step-up DC-DC converter
demonstration board based on the ST8R00W
Features
■Very low supply current: 500 µA (typ)
■Output voltage adjustable from 6 V to 12 V
■Output voltage accuracy: ±2%
■Output current up to 1 A
■Low ripple voltage: 5 mV (typ)
■Synchronous rectification
■High 90% efficiency: VO = 9 V (typ)
■Few external components
■RoHS compliant
Description
This demonstration board is based on the
ST8R00W family of synchronous step-up DC-DC
converters with current output cut-off function that
provide up to 1 A over an input voltage range of 4
V to 6 V and an output voltage range of 6 V to 12
V.
The ST8R00W is the continuous mode version,
that guarantees the lowest switching ripple when
the device is used at light load conditions.
The high switching frequency (1.2 MHz) allows
the use of tiny surface-mount components.
Along with 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-mounted ceramic capacitors.
STEVAL-ISA048V2
www.st.com
Circuit schematic STEVAL-ISA048V2
2/4 Doc ID 15975 Rev 1
1 Circuit schematic
Figure 1. Schematic diagram
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STEVAL-ISA048V2 Revision history
Doc ID 15975 Rev 1 3/4
2 Revision history
Table 1. Document revision history
Date Revision Changes
01-Jul-2009 1 Initial release.
STEVAL-ISA048V2
4/4 Doc ID 15975 Rev 1
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