DC/DC转换器和控制器 XC9242~XC9243

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概要

The XC9242/XC9243 series is a group of synchronous-rectification step-down DC/DC converters with a built-in 0.11Ω(TYP.) P-channel MOS driver transistor and 0.12Ω(TYP.) N-channel MOS switching transistor, designed to allow the use of ceramic capacitors. The small on-resistances of these two internal driver transistors enable a high efficiency, stable power supply with an output current up to 2A. The XC9242/XC9243 series has operating voltage range of 2.7V~6.0V and a 0.8V (±2.0%) reference voltage, and using externally connected resistors, the output voltage can be set freely from 0.9V. With an internal switching frequency of 1.2MHz or 2.4MHz, small external components can be used. , The XC9242 series is PWM control, and the XC9243 series is PWM/PFM, which automatically switches from PWM to PFM during light loads and provides high efficiency, high load response, low voltage ripple, can be achieved over a wide range of load conditions. The series have a high speed soft-start as fast as 1ms in typical for quick turn-on. It’s suitable for large-current application due to limit current is configured 4.0A in typical. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0μA or less. The integrated CL discharge function which enables the electric charge at the output capacitor CL to be discharged via the internal discharge switch located between the LX and VSS pins. Due to CL discharge function, malfunction on LX is prevented when Stand-by mode. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 2.5V or lower.

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