RP400xxx1A SERIES HIGH EFFICIENCY, SMALL PACKAGES, STEP-UP DC/DC CONVERTERS NO.EA-193-150909 OUTLINE RP400xxx1A Series are high efficiency, step-up DC/DC converter ICs packaged in compact 5pin SOT23 or 6pin DFN(PLP). This converter starts up of low voltage (Typ.0.8V) operation from one to two alkaline or a nickel-metal-hydride (NiMH) or one-cell Lithium-ion (Li+) battery. This IC consists of a reference voltage unit with soft start, a chip enable circuit, an error amplifier, phase compensation circuits, a slope circuit, a PWM control circuit, a start-up circuit, a PWM/VFM mode control circuit, internal switches and a protection circuit. As a protection circuit, RP400xxx1A has a current limit circuit which limits the peak current of the inductor at each clock cycle. A low ripple high efficiency step up DC/DC converter can be composed of RP400xxx1A Series with only an inductor, a diode and capacitors. This converter is based on a fixed frequency current mode PWM control which goes to power save mode (VFM mode) at light load automatically. RP400xxx1A Series has built-in Anti-ringing switch to prevent switching node from ringing, when the converter enters the discontinuous current mode. The output voltage of RP400K001A can be set within 1.8~5.0V (recommended range of output voltage) by external divider resistors. FEATURES Low Start-up Voltage guaranteed 0.8V Input Voltage Range 0.8V ~ 5.5V High Efficiency 85% (100mA / 3.3V, V = 1.5V, 25C) IN Output current 200mA / 3.3V (V = 1.5V) Typ.100mA / 2.0V (V = 1.2V) IN IN Internal Switch NMOS = 0.4 (V = 3.3V, 25C) OUT Built-in Phase Compensation, Soft Start, Peak Current Limit Protection PWM Oscillator Frequency 700kHz Output Voltage Range Fixed: 1.8V to 5.0V with 0.1V Stepwise Adjustable: 1.8V ~ 5.0V (RP400K001A only) (Recommended range of output voltage) Stable with Ceramic Capacitors Small Package DFN(PLP)1820-6, SOT23-5 Internal EMI suppression (Anti-ringing switch is included) APPLICATIONS MP3 players, PDA Digital Still Cameras LCD Bias Supplies Portable blood pressure meter Wireless Handset GPS 1 RP400xxx1A BLOCK DIAGRAMS 1. Adjustable Output with CE function RP400K001A Lx Startup Control Buffer V IN Circuit Logic V OUT Current PW M S ense Control E rro rA m p fosc - Chip V FB CE Osc En able + Vref VFM Con tro l GND 2. Fixed Output with CE function RP400xxx1A Lx Startup Control Buffer V Circuit IN Logic Current PW M Sense Control ErrorAmp Chip fosc - V OUT En able CE Osc + VFM Control Vref GND 2