Low power micros support capacitive touch sensor interfaces
1 min read
Silicon Laboratories has launched what it says is the industry's lowest power capacitive touch sense microcontrollers. The F99x family features devices with integrated touch sense technology for use in power and cost sensitive applications ranging from home automation to security systems.
In addition to consuming the lowest current per MHz, the mcus feature an integrated low drop out regulator that keeps the current constant at 150µA/MHz over the 1.8 to 3.6V operating range. According to SiLabs, the LDO helps reduce the mcu's drain on a battery by 50% compared to competing products.
The F99x range, part of SiLabs' QuickSense family, features fast and accurate capacitive sensing technology. All devices in the range feature a patent pending capacitance to digital converter (CDC) with a 40µs acquisition time. The company says the CDC offers superior noise immunity for reliable performance in challenging conditions, as well as when operating with thick laminate overlays.
MCU product manager Shahram Tadyon said: "Our solution is fast and accurate; competitors often offer devices that are either fast or sensitive. Our CDC technology does both. Getting a touch solution to work quickly and robustly is not easy"
Providing up to 14 capacitive sensing inputs, F99x mcus allow designers replace mechanical buttons, sliders and wheels. When combined with Si11xx QuickSense infrared and ambient light sensors, system designers can develop innovative 'touchless' proximity sensing interfaces.
The mcus integrate a 25MHz pipelined 8051 compatible core, a precision oscillator, a 12bit a/d converter, a temperature sensor, a voltage reference and four timers. The parts are available with 2, 4 and 8kbyte of flash and in 24pin qfn, 24pin qsop packages and 20pin 3 x 3mm qfn packages.
