9303可替换BD8301MUV；BD8305MUV驱动二十多颗LED白灯

9303 Series
High Efficiency, Synchronous Step-Up & Down DC / DC Controller ICs
■GENERAL DESCRIPTION
The 9303 series is highly efficient , synchronous PWM, PWM/PFM switchable step-up & down DC/DC controller ICs.
A versatile, large output current and high efficiency, step-up/down DC/DC controller can be realized using only basic
external components - transistors, coil, diode, capacitors, and resistors for detecting voltages. High efficiency is obtained
through the use of a synchronous rectification topology. The operation of the 9303 series can be switched between PWM
and PWM/PFM (auto switching) externally using the PWM pin. In PWM/PFM mode , the 9303 automat ically switches
from PWM to PFM during light loads and high efficiencies can be achieved over a wide range of output loads conditions.
Output noise can be easily reduced with PWM control since the frequency is fixed. Synchronous rectification control can be
switched to non-synchronous by using external signals (MODE pin). High efficiency can be regulated at heavy loads when
synchronous operation . The 9303 has a 0.9V (±2.0%) internal voltage supply and using externally connected
components, output voltage can be set freely between 2.0V to 6.0V. With an internal 300kHz switching frequency smaller
external components can be used. Soft-start time is internally set to 10ms and offers protection against in-rush currents
when the power is switched on and prevents voltage overshoot.
■TYPICAL APPLICATION CIRCUIT ■TYPICAL PERFORMANCE
CHARACTERISTICS
■APPLICATIONS
●PDAs
●Driver for White LED
●Portable audios
●Various power supplies
■FEATURES
Input Voltage Range : 2.0V ~ 10V
Output Voltage Range : 2.0V ~ 6.0V
(set freely with VFB=0.9V)
Oscillation Frequency : 300kHz (±15%)
Output Current : 800mA(VIN = 4.2V, VOUT=3.3V)
Stand-By Function : 3.0μA (MAX.)
Maximum Duty Cycle : 78% (TYP.)
High Efficiency : 84% (TYP.)
Soft-Start Time : 10ms (internally fixed)
Package : MSOP-8A
Environmentally Friendly: EU RoHS Compliant, Pb Free