R1210Nxx1x SERIES PWM STEP-UP DC/DC CONVERTER NO.EA-075-181214 OUTLINE The R1210Nxx1x Series are CMOS-based PWM step-up DC/DC Converter, with high accuracy, low supply current. Each of the R1210Nxx1x Series consists of an oscillator, a PWM circuit, a reference voltage unit, an error amplifier, phase compensation circuit, resistors for voltage detection, a chip enable circuit. Further, includes a controller against drastic load transient, a control transistor with low ON-Resistance, LX switch, and a protection circuit for LX switch and an output voltage detector. R1210Nxx1A Series contain further a circuit for changeover oscillator frequency each. A low ripple, high efficiency step-up DC/DC converter can be composed of this IC with only three external components, or an inductor, a diode and a capacitor. The R1210N Series can detect drastic change of output voltage with a circuit controller. The load transient response is improved compared with current model, furthermore the R1210Nxx1A Series have another function, that is, when the load current is small, oscillator frequency is decreased by a circuit for switching oscillator frequency from Typ. 100kHz to 35kHz, therefore, supply current is reduced. The built-in chip enable circuit can make the standby mode with ultra low quiescent current. Since the package for these ICs is small SOT-23-5, high density mounting of the ICs on board is possible. FEATURES External Components ....................................... Only an inductor, a diode, and a capacitor Standby Current ............................................... Max. 0.5 A Temperature-Drift Coefficient of Output Voltage Typ.100ppm/C Output Voltage Range ....................................... 2.2V to 3.5V (xx1A), 2.2V to 6.0V (xx1C/D), 0.1V steps Two choices of Basic Oscillator Frequency ..... 100kHz (xx1A/C), 180kHz (xx1D) Output Voltage Accuracy .................................. 2.5% Package ........................................................... SOT-23-5 Efficiency .......................................................... Typ. 88% (VIN=Set Output Voltage0.6 V , IOUT=10mA) Low Ripple, Low Noise Built-in a driver transistor with low on-resistance Start-up Voltage ................................................ Max. 0.9V Basic Frequency change-over circuit (only for xx1A type) from Typ. 100kHz to 35kHz APPLICATIONS Power source for battery-powered equipment. Power source for portable communication appliances, cameras, VCRs Power source for appliances of which require higher voltage than battery voltage. 1 R1210Nxx1x BLOCK DIAGRAMS Vref Circuit 2 VOUT Phase Comp. VLX limiter LX 5 Buffer PWM Controller OSC fosc Control 4 GND Chip Enable 1 CE SELECTION GUIDE Product Name Package Quantity per Reel Pb Free Halogen Free SOT-23-5 3,000 pcs Yes Yes R1210Nxx1 -TR-FE The output voltage can be designated. (0.1V steps) xx : xx1A : 2.2V(22) to 3.5V(35) xx1C/xx1D : 2.2V(22) to 6.0V(60) : The oscillator frequency and the Frequency Change-over circuit are options as follows. Code Oscillator frequency Frequency Change-over circuit A 100kHz Yes C 100kHz No D 180kHz No 2