This product belongs to the group of synchronous-rectification type DC/DC converters with a built-in 0.42O P-channel driver transistor and 0.52ON-channel switching transistor, designed to allow the use of ceramic capacitors. The ICs enable a high efficiency, stable power supply with an output current of 600mA to be configured using only a coil and two capacitors connected externally. Operating voltage range is from 2.0V to 6.0V. Output voltage is internally set in a range from 0.8V to 4.0V in increments of 50mV (accuracy: ±2.0%). With the built-in oscillator, ether 1.2MHz or 3.0MHz can be selected for suiting to your particular application. As for operation mode, the XC9235 series is PWM control, the XC9236 series is automatic PWM/PFM switching control and the XC9237 series can be manually switched between the PWM control mode and the automatic PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads (from light load to heavy load).
The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0µA or less. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 1.4V or lower. The XC9235B/XC9236B/XC9237B series provide short-time turn-on by the soft start function internally set in 0.25 ms (TYP). The XC9235B(C)/XC9236B(C)/XC9237B(C) integrate CL auto discharge function which enables the electric charge at the output capacitor CL to be discharged via the internal auto-discharge switch located between the LX and VSS pins. When the devices enter stand-by mode, output voltage quickly returns to the VSS level as a result of this function.