FingerTip

描述

FingerTip provides an optimal mix of low power, small size, low external part count and versatile features with unmatched true multi-touch performance in a single-chip touchscreen controller.

FingerTip uses a dedicated capacitance-to-voltage acquisition engine to implement the touch sensing. Coupled with the internal processor, the FingerTip touchscreen controller can detect, classify and track 10 finger touches with fast a report rate and response times.

The touch acquisition analog front-end has a wide dynamic range capable of coping with touchscreens of different sizes and configurations. This offers the flexibility to use FingerTip with multiple touchscreens using different ITO designs and overlay materials. One or two layer ITO sensors are supported using glass or PET substrates. FingerTip provides support for curved displays through proprietary node compensation hardware.

FingerTip's low-noise capacitive analog front-end provides enhanced noise suppression capabilities for various noise sources such as display, 3-phase noise and severe common mode noise introduced by battery chargers. The device utilizes ST proprietary hardware and firmware techniques to reduce power significantly in low power active mode and in low power idle mode, and incorporates multiple TX driving methods that can further boost the SNR and report rate.

FingerTip supports advanced features thanks to multi-mode sensing technology. The water rejection algorithm can detect water on the top of the screen and the device can still track one finger moving in the water without false touch or line breaking. The device supports multi-finger glove operation and small passive stylus.

The device also provides all types of SYNC mode (HSYNC and VSYNC) support, which enables touch sampling to be synchronized with the display SYNC signal. This enables it to work even with quad high definition displays.

The main processor implements a powerful 32-bit ARM M3 core with Flash that is capable of providing a high level of overall touch performance in terms of noise rejection, response time and power consumption. It runs concurrently with the analog front end and gives ample scope for implementation of complex touch-sensing tracking algorithms, advanced shape-based filtering and event reporting. The Flash size provides enough free space for further customization, even after implementation of ST firmware for all features.

The device supports I²C serial interface, I²C master interface, HID over I²C interface and SPI interface for greater flexibility.