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R1215D Datasheet, PDF (1/22 Pages) RICOH electronics devices division – STEP-UP DC/DC CONTOLLER
R1215D SERIES
STEP-UP DC/DC CONTOLLER
NO.EA-134-0604
OUTLINE
The R1215D Series are CMOS-based PWM step-up DC/DC converter controllers with low supply current.
Each of the R1215D Series consists of an oscillator, a PWM comparator 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, resisters, and capacitors.
Maximum duty cycle and the soft start time are easily adjustable with external resistors and capacitors. As for
the protection circuit, after the soft-starting time, if the maximum duty cycle is continued for a certain period, the
R1215D Series latch the external driver with its off state, or the latch-type protection circuit works.
The delay time for latch the state can be set with an external capacitor.
To release the protection circuit, restart with power-on (Voltage supplier is equal or less than UVLO detector
threshold level).
FEATURES
• Input Voltage Range ....................................................... 1.8V to 5.5V
• Two Options of Basic Oscillator Frequency .................... Typ.700kHz, 1.4MHz
• Built-in Latch-type Protection Function (Output Delay Time can be set with an external capacitor)
• Maximum Duty Cycle/Soft-start time ............................. Adjustable with external capacitors
• High Reference Voltage Accuracy .................................. ±1.5%
• UVLO Threshold level..................................................... Typ.1.6V/1.79V by mask option
• Small Temperature Coefficient of Reference Voltage ... Typ.±150ppm/°C
• Package .......................................................................... SON-8 ( t = Max. 0.9mm )
APPLICATIONS
• Constant Voltage Power Source for portable equipment.
• Constant Voltage Power Source for LCD and CCD.
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