RT\/CT is the timing resistor and timing capacitor of the external oscillator. The reference resistor is connected to the reference voltage output pin (VREF), and the reference capacitor is connected to the ground pin (four pins).
Pin 1 (COMP) is the compensating pin of the error amplifier. The RC compensation network should be connected between the pin and the inverting input of the error amplifier (VFB) to improve the performance of the error amplifier. Pin 2 (VFB) is the inverting input of the error amplifier. The feedback voltage is fed into the pin and compared with the reference voltage at the in-phase input of the error amplifier to set the error voltage.
Pin 3 (ISENSE) is the in-phase input of the current sampling comparator. The voltage drop at both ends of the current sampling resistor is applied to the pin and compared with the error voltage (maximum 1V) applied to the inverting input of the amplifier to determine the duty cycle of the output drive pulse.
Pin 5 (GROUND) is the grounding pin.
Pin 6 (OUTPUT) is the output pin. The low level of the pin output is 1.5V, and the output feed current (average) is 200mA. The high level of the output is 13.5V, and the output source current voltage can reach 30V.
Pin 7 (VCC) is the power supply voltage pin. The input power supply voltage of this series IC chip can reach 30V.
Pin 8 (VREF) is the reference voltage output terminal. The output voltage of the pin is 5V and the output current can reach 5mA. This reference voltage can be used to power an external circuit.