Capacitive touch switch

ROHM has published a mechanical ON/OFF switch that can be used in place of home appliances and OA machines, and has introduced the BU21079F, a control IC for capacitive touch switches. The new component is a new product following ROHM's electrostatic switch control series IC BU21072MUV/BU21078MUV. It inherits the high sensitivity and anti-noise characteristics of the market's high evaluation and achieves low power consumption through intermittent work. The packaging method uses the street-foot surface mount SOP16 that is strongly demanded by the home appliance industry.

The faceplate of the operating panel of a general electronic device arranges a plurality of switches, but these are mostly mechanical ON/OFF switches. In recent years, touch operation methods derived from smart phones have become popular. In order to avoid contact failure caused by mechanical wear, dust intrusion, and fashion design styles, various operation panels are being evaluated. In view of this, ROHM has developed a controller IC for capacitive touch screens and touch switches to which the aforementioned requirements are applied. Through ROHM's exclusive user interface technology, ROHM has achieved the characteristics of high sensitivity and resistance to noise, achieving the best of both worlds. Praise. On the other hand, the requirements for reducing power consumption and alleviating the load on the installation are increasing.

The newly developed BU21079F controller IC uses intermittent operation to significantly reduce power consumption while using the easy-to-surface-mount SOP16 in the appliance industry's standard package. OA machines such as printers and microwave ovens, IH cookers, and other products can easily be turned into simpler control panel products.

In general, electrostatic switches have the contradictory relationship of increasing sensitivity and anti-noise performance. However, the ROHM application's best-known analog technology enhances the noise discrimination function, high sensitivity, and high noise immunity through an optimized circuit. For this purpose, the thickness of the overlay can be used up to a thickness of 15 mm, and the distance between the switching electrode and the line is approximately 1 times that of the normal product. Machines that use curved panels, large home appliances, etc. So far, machines that do not easily mount electrostatic switches can be easily imported.

The BU21079F control IC operates from a 3.0V to 5.5V supply voltage. It has built-in I2C I/F, MCU, matrix switch expansion, and long-term key functions. The switch electrode supports 8 channels.