Stepless dimming lamp circuit using application-specific integrated circuit

It is a key-controlled stepless dimming lamp made of HT7700A dimming special integrated circuit . It is controlled by SB single button and has 96 levels of dimming brightness.     HT7700A is manufactured using CMOS large-scale process and adopts standard D1P-S pin package. The functions of the prepared pins are as follows: ① pin zC is the AC zero-crossing signal detection terminal; ② pin SFNSI//KEY is the touch sensing/keying signal input terminal; ③ pin FB is the input signal current input terminal when touching ;The 4th foot V;. , the negative terminal of the power supply; the 5th pin IRIC., the trigger signal output terminal, is used to trigger the thyristor; the 6th and 7th pins OSC2. OSC1 are the oscillation signal output and input terminals respectively, and an external 62kn resistor F pin 8 v. . , the positive terminal of the power supply.