Multi-Touch ‘Resistive’ Touchscreen Controller Chip
January 13, 2010 by admin
Filed under Design, Electronics, Featured Mechatronic Articles, Technology
As the latest high-tech devices such as smartphones, mobile internet devices and netbooks adopt multi-touch touchscreens to support increasingly sophisticated ‘apps’ and games,STMicroelectronics has introduced a multi-touch ‘resistive’ touchscreen controller chip to optimize the Bill of Materials of the electronics supporting this advanced capability. The STM32TS60 is the first member of ST’s new STMTouch family, which offers a broad portfolio of solutions including multi-touch devices and proximity and touch-key sensors.
The new multi-touch controller detects up to ten simultaneous touches with fingers, nails or stylus, enabling application designers to replace complex menu sequences with more direct and natural user controls. Actions made easier with multi-touch capabilities include browsing and selecting options, handwriting and data entry, arranging and sizing windows, picking up and dragging images, and fast and intuitive game play. Other abilities include drawing pictures, using touch pressure to adjust line thickness.
Employing resistive touch-panel technology, the STM32TS60 controller offers customers a real alternative and complements the recent industry trend for using capacitive touch technology. Resistive technology is a cost effective and mature high-volume solution that has seen dramatically improved performance over the past few years in terms of durability and display transparency. In addition, it easily overcomes EMI (electromagnetic interference) noise issues, which can be an inherent limitation with alternative touch technologies. Resistive technology is already widely used in PDAs and similar touch-enabled devices and the screens are readily available in standard LCD sizes and at competitive prices.
The new chip combines the company’s STM32 microcontroller architecture with PMatrixTM Multi-Touch technology from ST‘s partner Stantum to achieve fast response times while minimizing system complexity and component count.
The STM32TS60 single-core microcontroller is an added-value solution compared to other expensive multi-core processor or digital signal processors (DSPs) requiring specialized programming expertise.
The STM32TS60’s high EMI immunity makes it suitable for use in multi-function wireless products such as cellphones, notebook PCs, netbooks and mobile Internet devices. Moreover, its low power consumption helps to maximize operating times and recharge intervals, and is a direct benefit of the STM32’s energy-saving design features and ARM® Cortex™-M3 processor conceived for power-sensitive embedded applications. In addition, very-low-power idle mode with ‘wake-up on touch only’ helps further extend mobile battery life.
The STM32TS60 is housed in a 7 x 7mm 144-pin UFBGA package, and is now sampling to lead customers. Volume production is expected for Q2 2010.
New, Brighter, Sharper LED Signage
November 20, 2009 by admin
Filed under Electronics, Featured Mechatronic Articles, Technology
STMicroelectronics recently announced a new series of highly accurate LED drivers with automatic power saving, enabling electronic signage such as road signs, advertising, stadium displays, battery or solar-powered signs and similar equipment to deliver better, high-resolution viewing by ensuring consistent brightness across the viewing area.
The brightness of an LED is closely related to the drive current, usually supplied by a separate driver chip. As each new generation of LEDs produces greater brightness at lower drive current, overall efficiency is increasing but so, too, is the need for more accurate current control. This control is essential to prevent excessively bright or dark areas from damaging the visual effectiveness of signs and screens, which can employ tens of thousands of individual LEDs.
To provide the enhanced current control designers need, ST has introduced a family of driver chips capable of supplying 16 LED channels with driving capabilities of 3mA to 40mA and bit-to-bit accuracy within ±1%. This accuracy is superior in tolerance to alternative drivers providing comparable drive current. In addition, as a large display may require several thousand drivers, ST’s new devices also provides excellent current matching from chip to chip (±2%) to further enhance visual performance.
The new LED drivers are theSTP16CPP05, STP16CPPS05, STP16DPP05, and STP16DPPS05. In addition to their enhanced current accuracy, they also provide optional features including ST-patented automatic power saving, as well as built-in LED error detection. Available variants allow designers to specify either or both of these value-added features, in a choice of four industry-standard package options.
The patented automatic power saving allows the drivers to turn off independently when no LED drive data is provided. This function delivers two benefits: software design is simplified as no power-save algorithm is required; and power savings are increased as the drivers turn off more quickly than is generally possible under software control.
Error detection helps to improve maintenance and boost productivity for signage operators. If an LED in the display fails, ST’s LED drivers can detect either of the two possible failure modes (short circuit or open circuit) and communicate the failure to a central point. With this information, the system could be programmed to inform field maintenance crews of the necessary replacement parts in advance. In applications such as road signage, where reliability is critical, this feature can enable faults to be repaired quickly and efficiently.
