A new generation of touch stepless dimming and speed regulation circuit NB7232

1. Circuit overview: NB7232 touch (button) stepless dimming (speed adjustment)/switching circuit is a new product launched by Ningbo Science and Technology Park Yongjing Microelectronics Co., Ltd. after optimized design and process improvement. It is fully compatible with earlier LS7232, CS7232, M7232, SM7232, etc., use CMOS technology and have an operating voltage of 5V. Their performance and stability are much better than the early LS7232 (working voltage 15V) using PMOS technology. It is widely used to control incandescent lights (table lamps, chandeliers, etc.) and motor speeds (desk fans, ceiling fans, vacuum cleaners, etc.) in daily life. It uses a touch (or button) method together with a peripheral circuit mainly composed of a two-way thyristor. It controls the dimming (or speed adjustment) and switching of the light source (or motor), and has the memory function of the dimming or speed adjustment position. It is a novel upgraded product that gets rid of the traditional mechanical switch or potentiometer adjustment form. 2. Working principle: The circuit consists of input buffer, phase-locked loop, control logic, brightness memory, phase angle pointer, digital comparator and output driver. The block diagram is shown in Figure 1: The basic working principle of the circuit in Figure 1 is (dimming as an example): The human body is charged with the same frequency as the mains. When the human body touches the touch chip, the input buffer level is clipped, amplified, and shaped to become a standard MOS level. When the touch duration is greater than 32 milliseconds and less than 332 milliseconds, the control logic part of the control circuit is in a switching state. When the touch duration is greater than 332 milliseconds, the control logic part of the control circuit is in a dimming state, and the output trigger pulse phase angle changes continuously and periodically between 41 degrees and 159 degrees, and is divided into fast and slow according to the sensitivity of the human eye. and pause three processes. When the touch ends, the brightness memory memorizes the phase angle at that time. If another touch is applied for more than 32 milliseconds but less than 332 milliseconds and the circuit is in the off state, the phase angle is still memorized by this part to ensure that the circuit is in the on state next time. , maintain the original selected phase angle, and the light source maintains the original brightness. The synchronization of the trigger pulse and the mains power is guaranteed by the phase-locked loop, and the working clock of the circuit is also generated by it. At the same time, the circuit also has remote control (i.e. remote triggering) function and sleep (i.e. from light to dark and finally off) function, the duration of which is set by the external circuit. 3. Pin arrangement and function description: Pin function description: 1. Vss — 5V power supply. 2. Doze — fade-out function. When the conduction angle is maximum (159°). If the outside world applies 83±3 pulses to this pin, the conduction angle of the SCR continuously changes from 159° to 40°, and finally cuts off (no trigger pulse is output). 3. Cap — External filter capacitor for the phase-locked loop (reference value 0.47μF). 4. Syn—mains frequency synchronization signal input terminal. 5. Sen2 — Touch console. Low level trigger, human touch point. 6. Sala — Remote control terminal. High level trigger, good anti-interference, suitable for remote button dimming control. 7. VDD — 0V. 8. Out — Output trigger pulse. 4. Typical application circuit diagram 1 (component and load are connected in series, which can directly replace the original mechanical light or speed switch.) Diagram 2 (component and load are connected in parallel, the IC power source is taken from the mains, which is more stable and suitable for lamp production Adopted by the manufacturer) Note: 1. The triac SCR can choose one of 97A6 (about 1A), TLC336A (about 3A), or BT136-500D (about 6A) according to the load power. The selection principle is that the trigger current should be less than 25mA. 2. The value of C4 is between 0.1" and 0.47uF, and the value of C2 is between 2200" and 4700pF. 5. Main technical indicators: Power supply voltage: 5V. Output pulse width: 40ms. Output trigger pulse conduction angle: 41° to 159°. Dimming cycle (from brightest to brightest): 4.2s. Supply current: 1.5" 2.5mA. The output current sinks: ≤25mA. Output trigger pulse amplitude: Vss-3V. Dim pulse: 83±3.