Capacitive Touch Sensor Platform Optimized for TV Applications

Semtech Corp. has launched a new platform of easy-to-use capacitive sensing ICs optimized for the next-generation of energy-efficient, touch button television applications. The eight-channel SX8660/61 touch sensor platform features integrated LED drivers and an extended, 10cm range of proximity sensing. It is designed to easily replace legacy mechanical button controllers with an analog output interface (AOI) that supports the use of a buzzer for audible feedback making the platform fully compatible with a wide range of television designs.

The capacitive analog interface on the SX8660/61 ICs is designed with a highly accurate analog-to-digital converter (ADC) that provides superior sensitivity to work with thick overlay materials (up to 5mm) for extremely robust ESD immunity and to support a long, 10cm range of proximity detection. With current consumption as low as 70µA at operation, these ICs help designers meet the latest energy-efficiency eco-regulations for televisions.

The SX8660/61 platform also integrates eight, 256-step LED drivers with individual intensity (linear or logarithmic) fading control that is optimized for human vision. This allows design of buttons that automatically fade on when touched and fade off when released, with interval speed and initial and final light intensity levels set by the designer. Special single and continuous breathing modes are also available to enhance visual feedback to the user.

The SX8660/61 platform further simplifies capacitive touch control design and reduces time-to-market with integrated, multi-time programmable firmware that enables users to customize various parameters such as scan time, slave address, channel gain and sensitivity thresholds in their applications, without the need for new firmware development. Additionally, dedicated capacitive sense inputs eliminate the need for external resistors and capacitors, reducing design footprint, bill of materials (BOM) and complexity.

Semtech