Overview: R1212D Series PWM Step-up DC/DC Controller NO.EA-109-220608 OUTLINE
The R1212D is a CMOS-based PWM step-up DC/DC controller with low supply current. Internally, the R1212D consists of an oscillator, a PWM parator 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 stepup DC/DC converter can be posed of this IC with some external ponents, or an inductor, a diode, a power MOSFET, divider resistors, and capacitors. The maximum duty cycle and the soft start time are easily adjustable with external resistors and capacitors. In terms of maximum duty cycle, with or without internal limit can be set by mask options. As for the protection circuit, after the soft-starting time, if the maximum duty cycle is continued for a certain period, the R1212D latches 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).
