How to choose the appropriate working voltage of projected capacitive touch screens?

In the selection process of projected capacitive touch screens, the working voltage is an important parameter that needs to be carefully considered. Different voltage choices can affect system power consumption, signal quality, and overall cost. As a professional touchscreen manufacturer, we hope to help you make wiser choices through this article.
 

There are currently two main types of power supply voltages for projected capacitive touch screens in the market: 3.3V and 5V. The advantage of the 3.3V solution lies in its low power consumption, making it particularly suitable for battery powered portable devices such as handheld terminals and medical tablets. The 5V system has better anti-interference ability and is commonly used in industrial control equipment and outdoor display screens.
 

We once encountered a typical case: a customer used a 3.3V touch screen in a 5V system. Although a voltage divider resistor was added, the problem of touch failure still occurred after long-term operation. Later, we suggested switching to models that support 5V natively, and the problem was easily resolved. This example tells us that forcibly changing the operating voltage may affect the product's lifespan and reliability.
 

It is worth mentioning that the working voltage also affects the selection of communication interfaces for projected capacitive touch screens. The I ² C interface typically uses 3.3V, while RS232 may require 5V or higher voltage. When designing the system, it is essential to ensure that the touch screen matches the voltage level of the main control board, and if necessary, a voltage conversion chip should be added.