The R1280D002x Series are 2-channel PWM Step-up (as Channel 1)/Inverting (as Channel
2) DC/DC converter controllers with CMOS process.
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 0µA.
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. |
Input
Voltage Range 
R1280D 002x Series
