2844 adopts dual-in-line 8-pin package; Current pulse width modulator, input voltage range 5 ~ 30V, maximum power consumption =1W, oscillator frequency ≥500kHz, reference voltage =5V, voltage adjustment rate =6mV, current adjustment rate =6mA, output maximum current =1000mA, maximum duty cycle =95%. Contains oscillator, high gain error amplification, latch, push-pull output circuit, etc., with overvoltage, overcurrent detection protection function.
2844 pin feature
< p >
< br >
< p >
2844 Working principle
The power circuit adopts the current PWM control mode, which makes the flyback circuit form a double-loop feedback with good stability (output DC voltage isolation sampling feedback outer loop and primary coil magnetization peak current sampling feedback inner loop) control system, which can quickly adjust the pulse duty ratio through the PWM modulator of the switching power supply. Thus, the output voltage of the previous cycle and the primary coil magnetizing peak current are effectively adjusted in each cycle to achieve the purpose of stabilizing the output voltage. The biggest feature of this feedback control circuit is that it has faster dynamic response speed when the input voltage and load current change greatly, automatically limits the load current, and the compensation circuit is simple. Flyback circuit is suitable for low power switching power supply.