RP500x SERIES
step-down DC/DC Converters with synchronous rectifier
NO.EA-155-080522
OUTLINE
The RP500X Series are CMOS-based step-down DC/DC Converters with synchronous rectifier.
Each of these ICs consists of an oscillator, a switching control circuit, a reference voltage unit, an error
amplifier, a soft-start circuit, protection circuits, UVLO circuit, switching transistors, and so on. A low ripple, high
efficiency step-down DC/DC converter can be easily composed of this IC with only an inductor and capacitors. In
terms of the output voltage, since the feedback resistances are built-in, the voltage is fixed internally.
50mV(custom-made) step output can be set by laser-trim and 1.5% or 24mV tolerance depending on the output
voltage is guaranteed.
Mode alternative circuit works automatically for improving the efficiency. Considering fixed noise frequency,
PWM fixed control type is also available. As protection circuits, the current limit circuit which limits peak current
of Lx at each clock cycle, and the latch type protection circuit which works if the term of the over-current
condition keeps on a certain time exist. The latch-type protection circuit works to latch an internal driver with
keeping it disable. To release the condition of the protection, after disabling this IC with a chip enable circuit,
enable it again, or restart this IC with power-on or make the supply voltage at UVLO detector threshold level or
lower than UVLO.
Since packages are DFN(PLP)1820-6, SOT23-6, WLCSP-6 (0.16φ), high density mounting on boards is
possible.
FEATURES
zꢀInput Voltage Range.............................................. 2.55V to 5.50V
zꢀOutput Voltage....................................................... 1.1V to 3.3V
(It is possible in the range from1.1V to 3.3V with a step 0.1V)
zꢀHigh Accuracy Output Voltage .............................. ±1.5% (Vout≥1.6V)
±24mV (Vout<1.6V)
zꢀSupply Current......................................................... Typ.400µA(at PWM mode)
Typ.100µA(at PFM mode)
zꢀOscillator Frequency ............................................. Typ. 1.2MHz
zꢀBuilt-in Soft start Function ..................................... Typ.0.1ms
zꢀBuilt-in Latch type Protection ................................ Typ.1.5ms
zꢀBuilt-in UVLO Function.......................................... Typ. 2.2V
zꢀTwo choices of Switching Mode............................ Automatic PWM/PFM mode change / PWM fixed
zꢀPackages............................................................... DFN(PLP)1820-6, SOT23-6W, WLCSP-6 (0.16φ)
APPLICATIONS
zꢀPower source for portable equipment such as cellular, PDA, DSC, Notebook PC
zꢀPower source for HDD
zꢀPower source for Li-ion battery-used equipment
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