Semtech Debuts World’s Lowest Power, Fully Integrated Capacitive Touch Sensor IC Platform

The capacitive analog interface on each of the seven ICs in the SX864x platform is designed with a highly accurate ADC that provides superior sensitivity to work with overlay materials more than 5mm thick, offering extremely robust and ESD-immune system design. With current consumption as little as 80uA at operation, these ICs are the ideal choice for battery-powered devices. This SX864x platform also integrates eight, 256-step LED drivers with individual intensity and linear and logarithmic fading control that is optimized for human vision.

The SX864x devices are specifically designed to reduce capacitive touch control design time-to-market. Users may customize various parameters such as scan time, slave address, channel gain and sensitivity thresholds in their applications without the need for new firmware development. False triggers due to environmental factors such as temperature, humidity and dust can also be eliminated via our on-chip calibration algorithm.

“Unlike competitive alternatives, the SX864x family integrates all the functional blocks necessary for capacitive sensing in a tiny footprint that requires zero external components. This simplifies the PCB design and reduces the overall solution BOM cost,“ said Sam Massih, Product Line Manager, Consumer Analog Products for Semtech. “The integrated, advanced features of the SX864x platform coupled with their low power consumption, makes these ICs ideal for a wide range of capacitive sensing applications.”

The devices in the SX864x platform include the 12-channel SX8643/44/45, which are offered in 5mm x 5mm 32-QFN packages; and the 8-channel SX8646/47/48/49 that come in 4mm x4mm 28-QFN packages. Semtech guarantees all of these devices to operate over the extended (-40°C to +85°C) temperature range.

Key Features of the SX864x Platform

* Capacitive touch sensor platform for button, slider and wheel control applications; includes eight independent, 256-step LED drivers with auto-lightening mode and individual intensity and fading control
* High-resolution capacitive sensing (able to sense thru overlay materials up to 5mm thick)
* Low power optimized for battery-powered applications: 175uA (typ) in active mode; 80uA (typ) in doze mode and 8uA (typ) in sleep mode
* Auto offset compensation eliminates false triggers due to environmental factors
* Zero external components per sensor input
* Multi-time In-field programmable firmware parameters for ultimate flexibility