Capacitor Touch -Type Key Screen Applied High -Performance Touch Chip

Capacitor touch technology has developed rapidly, because it can well support the advantages of multi -touch, touch screen loss, long service life, etc., and have achieved rapid development.Touch chipThe emergence of technology has also made huge changes in the method of keys. The button operation becomes more flexible and comfortable, and the key panel is also more fashionable and beautiful.At present, touch chips have become one of the core components of modern electronic products. From mobile phones, tablets, smart watches, smart door locks, washing machines, cars, etc., they have a wide range of application scenarios.

There are two main types of touch chips currently used, one isresistanceThe other is a capacitor.It is widely used because of higher reliability of capacitors.At present, products that apply touch chips, single -point touch types are more common and widely used.With the continuous development of touch chips, various forms of touch buttons have appeared in our daily home appliances. For example, the emergence of roller wheels and slider -type kernels has enriched the application of touch chips.

Early touch chips are relatively simple and can only process keys.With the further development of technology, touch chips are no longer a simple button processing chip, and now it can be used as a masterMCUFor use, in addition to processing touch buttons, you can also process AD sampling, LED control, communication, etc.In the past, there must be two chips, one touch chip, and one master MCU. Now only one touch chip is needed to solve the problem, which greatly reduces the cost of the product.Key technology.

The working principle of the touch chip is achieved by sensing the changes in capacitance brought by the human body's touch; when the human body is close to the surface of the touch screen, it will cause the capacitance between the touch screen and the human bodyCapacity changes to calculate the specific touch position and operation gesture.This process requires a series of sensor technology, signal processing, and algorithm optimization to achieve the effect of high precision and high sensitivity.

There is an inductive capacitor between any two conductive objects. One button, that is, a pad, and the earth can also constitute an inductive capacitor. In the case of the surrounding environment unchanged, the inductive electrical capacity is a fixed and small value.When a human finger is close to the touch button, the inductive capacitance parallel pad and the inductive capacitance composed of the human finger and the earth will increase the total induction capacitance value.The capacitive touch button IC will change the determined signal that the key is pressed after detecting the inductive capacitance value of a key.Because the capacitive touch button does not have a mechanical structure, all the tests are slight changes in the power, so it will be more sensitive to various interference. Therefore, the design of the touch button design, the design of the touchpad, and the choice of touch IC are very critical.

Internal integrated high -resolution touch detection module and dedicated signal processing of capacitive touch chipsCircuitTo ensure that the capacitive touch chip has sensitive automatic recognition and tracking functions for environmental changes.In order to facilitate users to control the sensitivity of the touch button in the application, the capacitive touch chip also sets a sensitivity control bit.

After the touch chip set becomes MCU, the detection of the keys has become more flexible. You can use matrix scanning or AD sampling.Now a new touch chip can fully meet the requirements.

The GreenChip capacitance touch chip represented by Wan Shengxin-GTX314L is a 14-bit touch sensor series with multi-channel trigger sensors. It provides interrupt and wake-up functions through the continuous mode.Compatible with the processing signal of the original mechanical touch button.

GTX314L chip inside special useintegrated circuit, To have a high power voltage suppression ratio, which can reduce the occurrence of the key detection error. This feature guarantees that the chip in the application of adverse environmental conditions still has high reliability, and has a stronger anti -interference ability.Excessive high voltage tests can be used to inject current tests, and the effect is very obvious.

In addition, the chip integrates rich simulation and digital peripherals to provide interrupt functions; provides slide models; providesregisterWrite the lock function;EmbeddedDigital noise filter; intelligent sensitivity calibration; very easy to form various flexible combination door lock solutions.

The chip uses an automatic card search, and automatically shields the touch chip function before the probe card. There is no MCU intervention in the whole process. The MCU only needs to determine that IRQ can make the corresponding operation. The new implementation method is to reduce the overall standby power consumption of the smart door lock to less than 10UA.Define low power consumption.

Capacitor touch chip -GTX314L has characteristics:

① The range of power supply voltage is wide: 1.8V ～ 5.5V

②14 channel CAP. Sensor input

③ Embedded GreenTouch3TM engine

④ Smart sensitivity calibration; low power enhancer

⑤ Provide interrupt functions; provide slide pattern;

⑥ Support the I2C interface; provide the register to write the lock function

The peripheral circuit is simple and easy to debug; you can adjust the sensitivity of each button alone by easy to program, and pass the lead-free authentication (QFN-24L (4.00 x4.00x0.75, E = 0.50)) simulation compensation circuit; embedded number digitalNoise filter; GTX314L CTRL pin provides a chip IDI2C bus that can switch on the same chip for two chips.