XC9508

June 9, 2005 V7 ◆Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator plus Voltage Detector ◆Step-Down DC/DC Converter's Output Connected in Series with LDO Regulator ◆High Efficiency, Low Noise Regulated Output ◆Ultra Small Packages: MSOP-10, USP-10 ◆Small-Footprint ◆Output Current DC/DC:600mA, VR: 200mA ◆Ceramic Capacitor Compatible (Low ESR Capacitors) ■APPLICATIONS ●CD-R / RW, DVD ●HDD ●PDAs, portable communication modem ●Cellular phones ●Palmtop computers ●Cameras, video recorders ■GENERAL DESCRIPTION The XC9508 series consists of a step-down DC/DC converter and a high-speed LDO regulator connected in series with the DC/DC converter's output. A voltage detector is also built-in. A highly efficient, low noise output is possible since the regulator is stepped-down further from the DC/DC output. The DC/DC converter block incorporates a P-channel driver transistor and a synchronous N-channel switching transistor. With an external coil, diode and two capacitors, the XC9508 can deliver output currents up to 600mA at efficiencies over 90%. small ceramic capacitors. A choice of three switching frequencies are available, 300 kHz, 600 kHz, and 1.2 MHz. Output voltage settings for the DC/DC is set-up internally in 100mV steps within the range of 1.6V to 4.0V(± 2.0%) and for the VR are set-up internally within the range of 0.9V to 4.0V (± 2.0%). range is of 0.9V to 5.0V (± 2.0%). The soft start time of the series is internally set to 5ms. With the built-in U.V.L.O. (...