R1207N Series STEP-UP DC/DC CONVERTER NO.EA-298-190808 OUTLINE The R1207N Series are CMOS-based PWM control type step-up DC/DC converter ICs with low supply current. Each of these ICs consists of an NMOS FET, a diode, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier, a current limit circuit, an under voltage lockout circuit (UVLO), an over-voltage protection circuit (OVP), a soft-start circuit, a Maxduty limit circuit, and a thermal shutdown protection circuit. This step-up DC/DC converter can be easily built with a few external components such as a coil, a resistor, and a capacitor. As the protection functions, the R1207N Series have a Lx peak current limit function, an over voltage protection (OVP) function, an under voltage lock out (UVLO) function and a thermal shutdown function. The R1207N Series present the R1207N8xxA version that is optimized for the constant voltage power source, and the R1207N8xxB/C version that is optimized for driving the white LED with the constant current. The R1207N8xxB/C is an adjustable version that can change the LED brightness dynamically by using a 200Hz to 300kHz PWM signal toward the CE pin. The R1207N Series are available in TSOT-23-6 package. FEATURES Input Voltage Range .................................................. 2.3V to 5.5V (R1207N8xxA) 1.8V to 5.5V (R1207N8xxB/C) Supply Current ........................................................... Typ. 800A Standby Current ......................................................... Max. 5A Feedback Voltage ...................................................... 1.0V1.5% (R1207N8xxA) 0.2V10mV (R1207N8xxB) 0.4V10mV (R1207N8xxC) Oscillator Frequency .................................................. Typ. 1.2MHz Maximum Duty Cycle ................................................. Typ. 91% UVLO Function Typ.2.0V (Hys.Typ.0.2V) (R1207N8xxA) Typ.1.6V (Hys.Typ.0.1V) (R1207N8xxB/C) Lx Current Limit Function ........................................... Select from 350mA, 700mA Over Voltage Protection ............................................. Typ. 25V LED dimming control (R1207N8xxB/C) ................... by external PWM signal (Frequency 200Hz to 300kHz) Thermal Protection Function ...................................... Typ.150C(Hys.Typ.50C) Switch ON Resistance ............................................... Typ. 1.35 Package ..................................................................... TSOT-23-6 Ceramic capacitors are recommended APPLICATION Constant Voltage Power Source for portable equipment OLED power supply for portable equipment White LED Backlight for portable equipment 1 R1207N NO.EA-298-190808 SELECTION GUIDE The OVP threshold voltage, current limit and VFB/Auto discharge are user-selectable options. Product Name Package Quantity per Reel Pb Free Halogen Free TSOT-23-6 3,000 pcs Yes Yes R1207N8x3-TR-FE x : Designation of current limit. (1) 350mA (2) 700mA : Designation of VFB. (A) 1.0V (B) 0.2V (C) 0.4V 2