The R5210x is CMOS-based PWM step-down DC/DC converter combined with a voltage regulator
(VR) and a voltage detector (VD), 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 current limit circuit, a phase compensation circuit, a resistor net
for voltage detect circuit, an output driver transistor, and so on. A low ripple, high efficiency step-down
DC/DC converter can be easily composed of this IC with some external components,or an inductor, a diode,
and capacitors.
The oscillator frequency is 800kHz, therefore small inductor and capacitor can be used with this IC.
Further, this IC equips the under voltage lockout function (UVLO). If the input voltage becomes 2.35V (Typ.)
or less, the output of DC/DC converter is turned off. However, embedded voltage regulator and the detector
continue to operate.
The voltage regulator consists of a reference voltage unit, a resistor net for voltage detect circuit,
an error amplifier, an output driver transistor, and so on.
The built-in voltage detector supervises the input voltage and the output is N-channel open drain type.
Power-on reset delay time is also included and internally set typically at 10ms.
Wide
Range of Input Voltage 
R5210x
Series
