The new XC9270/XC9271 series from Torex Semiconductor Ltd. is high breakdown voltage dc-dc converter with 30V operation, 2A output, and an internal driver transistor. With an input voltage of up to 30V, input rating of 36V, peak voltage of 46V for 400ms and an operating ambient temperature range of -40 to +105 degrees, this series is designed for use in car accessories and industrial equipment applications. A 0.8V reference voltage source is incorporated and the output voltage can be set within a range of 1.2V to 12.0V using external resistors. 300kHz or 500kHz can be selected for the switching frequency. By synchronizing to an external clock, the generation of unwanted noise can be suppressed (accuracy ±25%).
Control methods are pwm control (XC9270 series) and pfm/pwm auto switching control (XC9271 series). The soft start time can be set as desired by adding an external capacitor to the SS pin. For the current limiting function, either latch type or auto recovery type can be selected. In addition to the current limiting function, a thermal shutdown circuit is incorporated to enable safer circuit design. A SOP-8FD package is used and greater integration of the power components is achieved. In addition, a high-side driver is incorporated so that fewer peripheral components are needed, making it possible to reduce the mounting area.
This series is an environment-friendly product that complies with the EU RoHS Directive and is Pb-free. Features of these dc-dc converters include: Supports 12V and 24V input; Absolute maximum rating: 36V, peak voltage: 46V (400ms); Avoidance of AM band is possible (incorporates an external clock synchronization function); PFM control increases efficiency at light loads (XC9271 series); and Latch type or auto recovery type can be selected for current limiting.