AS1333
650mA, Step Down DC/DC Converter for Portable Applications
Data Sheet
www.austriamicrosystems.com Revision 1.02 1 - 16
1 General Description
The AS1333 is a step-down DC-DC converter designed
to power portable applications from a single Li-Ion
battery. The device also achieves high-performance in
mobile phones and other applica tions requiring low
dropout voltage.
The AS1333 steps down an input voltage of 3.25V to
5.5V to a fixed output voltage of 3.09V.
Fixed-frequency PWM operation minimizes RF
interference. Shutdown function turns the device off and
reduces battery consumption to 0.01µA (typ.).
The AS1333 is available in a 8-pin WL-CSP package. A
high switching frequency (2 MHz) allows use of tiny
surface-mount components. Only three small external
surface-mount components, an inductor and two
ceramic capacitors are required.
2 Key Features
! PWM Switching Frequency: 2MHz
! Single Lithium-Ion Cell Operation
! Fixed Output Voltage (3.09V)
! Maximum load capability of 650mA
! High Efficiency (96% Typ at 3.6VIN, 3.09VOUT at
400mA) from internal synchronous rectification
! Current Overload Protection
! Thermal Overload Protection
! Soft Start
! Low Dropout Voltage (140 mΩ Typ PFET)
! 8-pin WL-CSP
3 Applications
The AS1333 is an ideal solution for cellular phones,
hand-held radios, RF PC cards, battery powered RF
devices, and RFIC chipsets.
Figure 1. Typical Application Circuit
AS1333
PGND
AGND
NC
EN
PVIN
VDD
SW
FB
3.09V
10 µF
3.3 µH
V
OUT
VIN
10 µF