STW4141_0606 Datasheet, PDF (8/31 Pages) STMicroelectronics – Single-coil dual-output step-down DC/DC converter for digital base band and multimedia processor supply

STw4141
STw4141 pinout
Table 1.
Pin
B4
C4
D4
STw4141 pin description (continued)
Symbol
Description
VOUT2
Output voltage 2
GND
Signal ground
Enable Input:
EN
EN = Low - Device in shutdown mode,
EN = High - Enable device
This pin must be connected either to VDD or GND.
PGND pin
This is the ground pin related to power signal. This pin should be connected to the board ground
plane by short and wide track or multiply vias to reduce impedance and EMI.
GND pins
This is the ground pin related to analog signal.
PVDD pin
VDD pin
VLX1/VLX2 pins
VOUT1 pin3
VOUT2 pin
This pin is designed to provide power to the device. This path leads high currents. It should be
wide and short to minimize track impedance to reduce losses and EMI.
This pin is designed to provide signal supply voltage to the device. There is no specific
requirement for its related track design.
External coil is connected on those pins. It should be placed as closed as possible to the device
in order minimize resistances which cause looses. These paths lead high currents.
It is the first output voltage of this device. This path leads high currents. It should be wide and
short to minimize track impedance to reduce losses and EMI.
It is the second output voltage of this device. This path leads high currents. It should be wide and
short to minimize track impedance to reduce losses and EMI.
FB1 pin
Intended to measure VOUT1 voltage in order to ensure the regulation of this output.
FB2 pin
Intended to measure VOUT2 voltage in order to ensure the regulation of this output.
ENABLE pin
This is the enable pin of the device. Pulling this pin to ground, forces the device into shutdown
mode. Pulling this pin to VDD enables the device. This pin must be terminated.
MODE/SYNC pin ^{The MODE/SYNC pin is a multipurpose pin which provides mode selection and frequency}
synchronization.
The device can also be synchronized to an external clock signal from 600 kHz to 1.5 MHz by the
MODE/SYNC pin. During synchronization, the mode is forced to PWM mode and the top switch
turn-on is synchronized to the rising edge of the external clock.
AUTO pin
This pin allows the device to automatically switch from PWM to PFM mode following load on both
2 outputs.
STATE pin
This output pin informs user in which state the device is working: PWM or PFM mode.
VSEL pin
This pin is used to reduce V_OUT2 (CORE) output voltage in order to reduce the processor power
consumption when entering into sleep mode.
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