What is TTP223 touch sensor? Touch sensor TTP223 working

TTO223 or the touch sensor which we commonly use works as a capacitive touch switch which is ideal for driving devices under microcontroller working voltage range

  • TTP223 touch sensor is the very common sensor that is used to control the system with human interface with the system. TTP capacitive touch sensor, widely used sensor in automation and project.
  • So, here we are talking about, “what is TTP223 touch sensor?” The touch sensor can be used in home automation and in many other household things. Like you can attach the sensor to the wall on any other places
  • Touch Sensor are used for controlling the system or device physically with the touch response of body to sensor. It comes in various sizes and multiple sensor points in single module variants.
  • This sensor seems to be small in comparison to other, but the touch sensitivity of this sensor is good for beginner purposes.
  • The only drawback of the most common Capacitive touch sensor i.e., TTP223 touch sensor is that is does not have any sensitivity control potentiometer or trimmer capacitor available o the module.
  • The sensor also can be found in two variants, TTP223-BA6 & TTP223N-BA6. The pros & cons of the both IC’s is opposite to each other, which we’ll discuss in later part of the article.

TTP223 Touch Sensor schamatic

ttp223 touch sensor
  • The application circuit of the TTP223 touch sensor or TTP223 IC from it’s datasheet which you can see. But I’ll explain each pinout, and it’s working in the working section of the article.
  • Other than this, to control the sensitivity of the sensor or human touch, we have to desolder the SMD Capacitor that has pre soldered onto the board and then replace it which a trimmer or the fixed value we want.
  • Also, due to its most common range of the voltage operation in TTP223 Touch sensor, it can be used with almost any of the microcontroller or microprocessor.
  • The PCB of the module is quite compact so the sensing pas of the sensor it rather small, but you can extend that by attaching a separate wire of the large plate for more area of sensing.
ttp223 touch sensor

TTP223 Touch Sensor Working

  • The working of the TTP223 touch sensor IC is very simple, can ca be understood easily through a thorough reading of the datasheet which is provided above.
  • This IC comes in a SOT-23 6L package which is for both packages, either TTP23 & TTP223N. The 4 pins which are used other than Power pins are used for various changes.
  • Q pin in the above circuit is the output pin which giver either high or low output which gives signal to the microcontroller the state of this pin can be changed according to the table mentioned below.
TTP223 touch sensor
  • The sensitivity of the sensor can be changed via changing the Cs capacitor in the circuit diagram. Which is connected to the Input pin of the IC & GND and in parallel with the touchpad.
  • Upon touching the pad, the capacitance of the circuit increases and hence the IC registers the touch.

Advantages :

  • The main and most important advantages of this sensor is that it can be used withoout actually physically any button or switch.
  • Secondly due to its small size it can be fixed in almost any place without any issue for space and size. Frthermore you can also fix it some other place and extend a wire through the touch pin as shown in above schematic to the body of the area where sensitivity needs to be arranged.
  • The working voltage level of theTTP223 touch sensor IC is2.0V to 5.5Vw hich is easily acceptable for almost all types of microcontroller and development boards. The sensitivity may change according to the voltage level with refernence to the microcontroller used.
  • It is very low cost for a project whivh need capacitive touch sensitivity fro controll appliances or task and is mostly used in home applinaces like smart watches, Monitor buttons etc.
  • This sensor comes in multiples sensing pads at onces whcih are useful for making touch response pads in a single place thus resuding wiring and space.

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Disadvantages :

  • The main disadvantage of this sensor is that you have to isolate it from other electric or magnetic fields or places that can provide huma like touch to the sensor as due to which the sensor may react to that as touch and your project or task may malfunction.
  • Secondly, you have to make sure which using wire to extend the touch pin that you properly place wire away from other power lines as this may affect the sensitivity and may affect your work.
  • To change the sensitivity you have to dsolder the SMD capacitor on the PCB whcih is not quiet easy for beginners or someone whoc doesn’t have equipments.

This is the complete working and explanation of TTP223 touch sensor, I hope you like it. If you need any other information regarding this then comment down below, I’ll amend the changes as soon as possible.


Q. What is the Working voltage level of the TTP223 Touch Sensor?

The working voltage level of the TTP223 touch sensor is 2.0V to 5.5V which is the common voltage for almost all types of microcontrollers and development boards.

Q. Can this sensor be used with metal body object to make them work?

Yes, you can use this but the range of the sensor like the electric field genetrated by the mtael body may ressult in malfunction as it can detect human touch from a quiete range og about 1-3 cm (depending upon the size of the body).

Q. What type of output is given by the TTP223 Touch sensor?

TTP223 Touch sensor gives only DIGITAL OUTPUT, the voltage range of the signal however can be adjusted or depends upon the working voltage of the Sensor.

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