By Torex Semiconductor, Ltd. 18
Torex Semiconductor's XC9246/XC9247 series is a 16 V step-down DC/DC converter with a built-in driver transistor. The series provides high efficiency and a stable power supply with output currents up to 1 A. The series is designed for use with small ceramic capacitors.
The series has a 1.0 V reference voltage, and using externally connected resistors, the output voltage can be set freely. With an internal switching frequency of 1.2 MHz, small external components can be used. The soft-start time is internally set to 1.5 ms typical, but can be adjusted to set a longer time using an external resistor and capacitor.
As for operation mode, the XC9246 series is PWM control and the XC9247 series is automatic PWM/PFM switching control. In PWM/PFM switching control mode, the device provides fast response, low ripple and high efficiency over the full range of loads (from light load to heavy load).
With the UVLO (Under Voltage Lock Out) function, the internal driver transistor is forced OFF when input voltage becomes lower than detect voltage. The series includes current limit, thermal shutdown, and short-circuit protection.