First, the circuit Overview
NB7232 touch (touch)-free dimming (governor) / switch circuit, Science and Technology Park of Ningbo City, Ningbo Microelectronics Co., Ltd design and process improvements through optimization of new products launched, fully compatible with earlier LS7232, CS7232, M7232, SM7232, etc., the use of CMOS Technology, Operating Voltage 5V, the earlier use of PMOS Technology LS7232 (Operating Voltage 15V) of the Performance and Stability is much Better. Widely used in Life incandescent Light (Lamps, Chandeliers, etc.) and motor speed (Table, ceiling fans, vacuum cleaners, etc.) control, it formed a mainly peripheral circuits triac with, the use of touch (or key) mode of light (or motor) dimming (or speed) and the switch control Dimming and Speed ??Control with Memory function or position. From the traditional Mechanical Potentiometer Adjustment Switches or in the form of a new upgraded Product.
Second, the principle
Circuit from the INPUT buffer, PLL, Control Logic, Memory brightness, phase Angle pointer, Digital comparator and output Driver Component. The Block Diagram shown in Figure One:
Figure a Basic principle of the Circuit is (Dimming for example): the Human body charged with electricity the same Frequency, when the Human Contact Touch of Films, by Clipping the INPUT buffer Stage, Amplification, Shaping, Becoming a standard MOS level. Touch Duration more than 32 MS is less than 332 milliseconds, the Control Logic Part of the Control Circuit Switching State was. When the Touch Duration Greater than 332 milliseconds, the Control Logic Part of the Dimming Control Circuit was Working, the output phase Angle Trigger Pulse of 41 degrees to 159 degrees Continuous Cycle, and according to the Human Eye's Sensibility, is divided into Fast, Slow, and a PAUSE of three processes. When Touching the End of the brightness of the phase Angle when the Memory of the Memory, if more giving than 32 milliseconds, less than 332 milliseconds the touch, the circuit was off state, the phase angle is still the part of the memory, to ensure that the next circuit an open state, to keep the original selected phase angle, the light Original source to maintain the brightness. Trigger Pulse Synchronous with the Mains, ensure that the PLL Circuit clock work, but also by its formation. At the same Time, the Circuit also has a Remote Control (that is, the Remote Trigger) Capabilities, and getting to sleep (from light to dark, the last off) function, and its duration set by the external circuit.
Third, the pin arrangement and Function
Pin Function:
1. Vss - 5V power supply.
2. Doze - Dimming function. When the conduction of the Maximum Angle (159 °) Time. impose on the outside of the Foot 83 ± 3 pulses, the SCR conduction Angle Continuous variable from 159 ° to 40 °, the Final Deadline (no output trigger pulse).
3. Cap - External PLL filter capacitor (reference value 0.47µF).
4. Syn - mains frequency synchronization signal is input.
5. Sen2 - Touch Control Side. Low level Trigger, the body Touch Points.
6. Sala - Remote Control client. High level Trigger, interference, Suitable for a more long-Range Dimming Control Button.
7. VDD - 0V.
8. Out - the output trigger pulse.
Fourth, the typical application circuit
Figure I (component and load in series connection can directly replace the original lamp or a mechanical speed control switch.)
Figure II (components and load and join law, IC power supply from more stable electricity for lighting manufacturers to adopt)
Note:
1. TRIAC SCR power according to the load size selection 97A6 (about 1A), TLC336A (about 3A), BT136-500D (about 6A) a, principle of selection is less than the trigger current of 25mA.
2. C4 values ??in between 0.1 ~ 0.47uF, C2 value between the 2200 ~ 4700pF.
Fifth, the major technical indicators
R Supply voltage: 5V.
Output pulse width: 40ms.
Output trigger pulse conduction angle: 41 ° ~ 159 °.
Dimming cycle (light from the brightest to the most): 4.2s.
Supply current: 1.5 ~ 2.5mA.
Output sink current: = 25mA.
Output trigger pulse amplitude: Vss-3V.
Dimming pulse: 83 ± 3.