R1223N SERIES
PWM/VFM step-down DC/DC Controller
NO.
EA-065-130424
OUTLINE
The R1223N Series are CMOS-based PWM step-down DC/DC Converter controllers with low supply current.
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.
With a PWM/VFM alternative circuit, when the load current is small, the operation is au...