SM7232, CS7232 dimming control application specific integrated circuit

The core component of the circuit is an SM7232 dimming dedicated integrated circuit . Its 8 pin functions are as follows: 1 pin is VDD,
the positive terminal of the power supply; 2 pins DOZE, 5 pins SEN, and 6 pins SLAVE are all phase shift control input terminals, among which Pin 5 is the touch control
input terminal. The hand touch signal is input through two high-value resistors R5 and R4. When the touch time is within 39ms~399ms,
the light can be turned on and off. The touch time is greater than 399ms (about 0.4s). It can turn on or adjust the light. If you hold the touch pad M for a long time, the brightness of the
light will automatically fade from dark to bright and then back to dim. Let go when you think it is appropriate, and the brightness will be fixed. If you want to turn off the light, just touch it briefly (small
(less than 0.4s), and then touch it briefly (less than 0.4s) to turn on the light and maintain the original brightness. {The function of pin 6 is
similar to that of pin 5, except that it has special logic inside and is mainly used for long-distance control . When used, the circuit is less susceptible to interference and malfunction
; pin 4, SYN, is the power frequency synchronization input, which is locked by the internal PLL as a phase shift circuit and brightness memory circuit
to generate a zero-phase reference for outputting trigger pulses; pin 3, CAP, It is the external terminal of the low-pass filter capacitor of the internal PLL; pin 7 vss is
the negative terminal of the power supply; pin 8 OUT is the trigger pulse output terminal.
    VD1, VD3, Rl and C3 form a resistor step-down half-wave rectification and voltage stabilizing circuit, which outputs 5v DC power for SM7232
. R2 provides synchronization signal for pin 4. C2 filters out spike interference. cl is the PLL filter capacitor. R6
provides the trigger signal for the thyristor vs. The resistance value of R3 will affect the touch sensitivity, generally it can be selected between 220k O ~680k O.
    The two high-impedance resistors R4 and R5 connected to the touch piece M ensure the absolute safety of the user.