The R1223N Series are PWM step-down DC/DC Converter controllers with low supply current by CMOS process. Each of these ICs consists of an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a soft-start circuit, a protection circuit, a PWM/VFM alternative circuit, a chip enable circuit, and resistors for voltage detection. A low ripple, high efficiency step-down DC/DC converter can be easily composed of this IC with only four external components, or a power-transistor, an inductor, a diode and a capacitor.

FEATURES

Range of Input Voltage · · · · · · · · · · · · ·2.3V~13.2V

Built-in Soft-start Function and Two choices of Protection Function (Latch-type or Reset type)

Two choices of Oscillator Frequency · · · · · ·300kHz, 500kHz

High Efficiency · · · · · · · · · · · · · · · · · ·TYP. 90

Output Voltage · · · · · · · · · · · · · · · · ·Stepwise Setting with a step of 0.1V in the range of 1.5V ~5.0V

Standby Current · · · · · · · · · · · · · · · · ·TYP. 0µA

High Accuracy Output Voltage · · · · · · · · · ·±2.0

Low Temperature-Drift Coefficient of Output Voltage · · · · ·TYP. ±100ppm/°C