R1280D002x SERIES 2CH PWM DC/DC CONTROLLER NO.EA-086-160125 OUTLINE The R1280D002x Series are CMOS-based 2-channel PWM Step-up (as Channel 1)/Inverting (as Channel 2) DC/DC converter controllers. Each of the R1280D002x Series consists of an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a reference current unit, a protection circuit, and an under voltage lockout (UVLO) circuit. A high efficiency Step-up/Inverting DC/DC converter can be composed of this IC with inductors, diodes, power MOSFETs, resisters, and capacitors. Each Output Voltage can be adjustable with external resistors, while soft-start time can be adjustable with external capacitors. Maximum Duty Cycle of R1280D002A and C series can be also adjustable with external resistors. Maximum Duty Cycle of R1280D002B is built-in as 90%(Typ.). When CE pin of R1280D002B is set at GND level, this IC turns off external power MOSFETs of Step- up/Inverting as Standby-mode. Standby current is typically 0A. As for a protection circuit, if Maximum duty cycle of either Step-up DC/DC converter side or Inverting DC/DC converter side is continued for a certain time, the R1280D Series latch both external drivers with their off state by its Latch-type protection circuit. Delay time for protection is internally fixed typically at 100ms. To release the protection circuit, restart with power-on (Voltage supplier is equal or less than UVLO detector threshold level), or as for R1280D002B, once after making the circuit be stand-by with chip enable pin and enable the circuit again. FEATURES Input Voltage Range ......................................... 2.5V to 5.5V Built-in Latch-type Protection Function by monitoring duty cycle (Fixed Delay Time Typ. 100ms) Oscillator Frequency ......................................... 700kHz (R1280D002A,B)/200kHz (R1280D002C) Maximum Duty Cycle ........................................ Typ. 90% (Only applied to R1280D002B Series) High Reference Voltage Accuracy .................... 1.5% U.V.L.O. Threshold ............................................ Typ. 2.2V (Hysteresis: Typ. 0.1V) Small Package .................................................. thin SON-10 (package thickness Max. 0.9mm) APPLICATIONS Constant Voltage Power Source for Portable Equipment. Constant Voltage Power Source for LCD and CCD. 1 R1280D002x BLOCK DIAGRAM R1280D002A/C R1280D002B 2