STW4141 Datasheet, PDF (1/27 Pages) STMicroelectronics – Single Coil Dual Output Step Down DC/DC Converter for Digital Base Band and Multimedia Processor Supply

STw4141
Single Coil Dual Output Step Down DC/DC Converter
for Digital Base Band and Multimedia Processor Supply
PRELIMINARY DATA
Features
■ Single coil dual output switching converter for
digital core supply & digital I/Os supply
– Digital I/O supply:V_OUT1 @ 200 mA
– CPU CORE supply:V_OUT2 @ 400 mA
■ Wide range of fixed output voltage
configurations available
■ High efficiency synchronous step down
converter with up to 92 % for the entire device
■ Size and cost optimized application board
(7x8 mm, height 1.2mm) three capacitors and
only one inductor necessary for both outputs
■ 2.7 V to 5.5 V battery input range
■ ±100mV output voltage accuracy full range in
PWM (Including Line and Load Transients)
■ 900 kHz fixed frequency PWM operation
■ PFM mode operation at light load current
■ PWM/PFM switch can be done automatically or
forced by setting external pins (AUTO and
MODE/SYNC)
■ MODE/SYNC input pin for external clock
synchronization from 600 kHz to 1.5 MHz
■ VSEL input pin for V_OUT2/V_OUT2(red.) selection
■ Ultra low shutdown current (Iq<1 µA)
■ Short circuit and thermal shutdown protections
Solution size
7 x 8 mm
TFBGA 3x3mm
16 bumps 0.5 mm pitch
Applications
■ Mobile phones
■ PDAs and hand held terminals
■ Portable media players
■ Digital still camera
■ WLAN and Bluetooth applications
Description
The STw4141 is a single coil dual output
synchronous step down DC/DC converter that
requires only four standard external components.
It operates at a fixed 900 kHz switching frequency
in PWM mode. The device can operate in PFM
mode to maintain high efficiency over the full
range of output currents.
The STw4141 application requires a very small
PCB area and offers a very efficient, accurate,
space and cost saving solution to fulfill the
requirements of digital baseband or multimedia
processor supply (CORE & I/O).
Application Test Circuit
L 4.7 µH
V_IN=2.7V to 5.5V
VLX1
VLX2
PVDD
C_IN
10 µF
6.3 V
VDD
EN
AUTO
VSEL
MODE/SYNC
A2
A3
B1
D3
D4
STw4141
C2
C3
C1 _A1
C4
B3
VOUT1
A4
D1 ^FB1
VOUT2
B4
FB2
D2
STATE
B2
C_OUT1
22 µF
6.3 V
C_OUT2
22 µF
6.3 V
V_OUT1=1.8V
V_OUT2=1.0V/1.2V
PGND GND T_MODE
December 2005
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to
change without notice.
Rev 1
1/27
www.st.com
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