6-channel Capacitive Touch Sensor


Tokyo Japan, Oct 16 2013, Asahi Kasei Microdevices Corporation (AKM) today launched the AK4161, a low power 6-channel capacitive touch sensor. A capacitive touch sensor can detect a human body touch from the capacitance changes of electrodes formed by a conductor, typically used for ON/OFF switches. With this capacitive touch sensor, flat surface switches can be realized, enhancing design possibilities with a flexible form factor. Compared to mechanical switches, capacitive touch sensors have better endurance, and waterproof performance. The AK4161 can also be used for slider and wheel switches, since it reads data not only by detecting touch or release, but also real-time capacitive changes from sense terminals.


The AK4161 provides stable touch detection performance by continuous parameter correction as the input capacitance changes due to environmental drift, such as temperature and humidity. The automatic initial setting function sets the charge current and charge time for each sense terminal based on the size and the shape of a touch switch, simplifying the initial setting of the touch switch. In addition, erroneous operation in a noisy environment can be prevented by a noise reduction filter and a data update stop function. The noise reduction filter implements two median averaging filters, allowing for selection of the number of data to calculate an average value depending on the environment. The data update stop function monitors measurement values of each sense terminal, which can stop updating status of the relevant channels if it is a noisy environment.


The six sensor input channels can be configured as LED drivers or GPIO’s, making the device capable of multi-detection of touch switches, such as LED illumination and mechanical switches. Two channels of the sensor input can be configured as interrupt outputs for data updating, error detection and etc. The AK4161 is suitable for a wide variety of applications since different interrupt conditions can be applied to these channels.


The AK4161 operates off of a of single power supply ranging from 1.71V to 3.6V. Various settings such as filtering, de-bouncing and detecting cycles can be accomplished through a low voltage I2C serial control interface. The AK4161 is housed in a space saving 16-pin QFN package.


Evaluation boards and samples are available now.  

To obtain more information about the AK4161, please visit here.


*I2C-bus is a trademark of NXP B.V.