STW4141 STMicroelectronics, STW4141 Datasheet - Page 5

• Manufacturer Part Number: STW4141
• Description: Single Coil Dual Output Step Down Dc/dc Converter For Digital Base Band And Multimedia Processor Supply
• Manufacturer: STMicroelectronics

STw4141
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Pin assignment in TFBGA 3x3 mm - 16 bumps 0.5 mm pitch . . . . . . . . . . . . . . . . . . . . . . . 6
Smooth start-up sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Settling time of VOUT2, IOUT1 = 200mA, IOUT2 = 400mA . . . . . . . . . . . . . . . . . . . . . . . . 11
Line transient, VOUT1 = 1.8V @ 100mA, VOUT2 = 1.2V @ 100mA . . . . . . . . . . . . . . . . . 12
Load transient in AUTO mode VIN = 3.6V, VOUT1 = 1.8V, VOUT2 = 1.2V . . . . . . . . . . . . 12
Load transient in PWM mode, IOUT1 = 1mA to 200mA, IOUT2 = 1mA to 400mA. . . . . . . 13
Switching between PFM to PWM - VIN = 3.6V, IOUT1 = 10mA, IOUT2 = 10mA. . . . . . . . 14
Switching between PWM to PFM - VIN = 3.6V, IOUT1 = 10mA, IOUT2 = 10mA. . . . . . . . 14
Switching regulator efficiency in PWM mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Switching regulator efficiency in auto mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Output voltages versus output currents in PWM and PFM . . . . . . . . . . . . . . . . . . . . . . . . . 17
Automatic PWM/PFM switch schematic example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
PWM/PFM forced mode schematic example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Application using external clock synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Board layout track length and width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Demoboard top layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Demoboard assembled with 22 µF output capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
TFBGA16 ball pad spacing and track parameters to internal pads . . . . . . . . . . . . . . . . . . 24
PCB routing example using TFBGA16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
TFBGA 3x3x1.20 16 F4x4 0.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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