OUTLINE

The R1211x Series are CMOS-based PWM step-up DC/DC converter controllers with low supply current. Each of the R1211x Series consists of an oscillator,a PWM control circuit, a reference voltage unit, an error amplifier, a reference current unit, a protection circuit, and an under voltage lockout (UVLO) circuit. A low ripple, high efficiency step-up DC/DC converter can be composed of this IC with some external components, or an inductor, a diode, a power MOSFET, divider resisters, and capacitors.

FEATURES

• Standby Current................................................Typ. 0µA (for B/D version)

• Input Voltage Range.........................................2.5V to 6.0V

• Built-in Latch-type Protection Function (Output Delay Time can be set with an external capacitor)

• Two Options of Basic Oscillator Frequency ......300kHz, 700kHz

• Max Duty Cycle.................................................Typ. 90

• High Reference Voltage Accuracy ....................±1.5

• U.V.L.O. Threshold level ...................................Typ. 2.2V (Hysteresis Typ. 0.13V)

• Small Packages ................................................SOT-23-6W or thin (package height Max. 0.85mm) SON-6

APPLICATIONS

• Constant Voltage Power Source for portable equipment.

• Constant Voltage Power Source for LCD and CCD.