Date: 16/01/2012

Larger screen supporting capacitive touch screen controllers from Cypress and Atmel

The touch screen controller IC market is getting hotter due to high growth of shipment in tablet computers and also same is expected for ultra books this year.

The two leading semiconductor chip companies addressing this market for some time are Cypress and Atmel. The reliability of touch screen is very important for the success of a tablet and ultrabook. The noise, sensitivity and power consumption are the parameters both Cypress and Atmel are focusing. Both have announced touch screen controller ICs for tablets. Here are the details.

Cypress Semiconductor's new capacitive touch controller IC CY8CTMA1036 features 65 sense-I/Os for mobile devices such as tablet and ultrabook computers with screen sizes up to 12 inches. Cypress claims this touch controller IC offers world's best signal-to-noise ratio (SNR). This device as part of Cypress' Gen4 family said to offer lowest active power consumption, best tracking accuracy and high refresh rates. OS support includes both Windows 8 and Android.

The new CY8CTMA1036 is powered by 32-bit ARM Cortex featuring 65 sensing I/O channels with support for up to 1036 nodes on the screen, 35 percent more than any other single-chip solution, claims Cypress. Cypress suggetss additional sensing channels are essential for greater accuracy, linearity, support for smaller sized fingers and the ability to resolve multiple fingers close together.

"We're getting the same positive reaction from tablet manufacturers as we did from the handset sector," said Dhwani Vyas, Vice President of Cypress's User Interface Business Unit. "Customers are excited to apply the benefits of Gen4's noise immunity, low power and superior performance in a single-chip package to their tablet designs. We're sampling multiple customers now and expect to start production shipments by the end of this quarter."

Cypress says it is the first and only touchscreen IC that delivers built-in 10V Tx to drive the touch panel at 10V. Because SNR is directly proportional to the voltage at which the panel is driven, this feature allows Cypress to offer nearly four times the SNR of the next closest competitor, claims Cypress.

The Gen4 family eliminate display noise in hardware by using a tech called Display Armor supporting even noisy but low cost LCD panels such as ACVCOM LCDs. This allows touchscreen designers to make their products thinner by removing the air gap between the display and the sensor, and also less expensive by removing the shield layer in the sensor. Display Armor allows Gen4 to operate seamlessly with direct lamination, on-cell and in-cell stackups, regardless of the display chemistry.

The Gen4 platform consumes active power consumption of 2 mW, and a deep sleep mode that only draws 1.8 uW with wake-up via address match on the COM port. The Gen4 product family also boasts the industry's fastest refresh rate of 400Hz, and has the unique ability to scan a capacitive touch panel at 1,000 Hz - both industry-best metrics, as per Cypress. The Gen4 family features high accuracy and linearity of 0.2 mm.

Other features include:
Waterproofed and meet IP-67 standards
1-mm stylus support for Asian character sets and accurate handwriting capture
Hover sensing to provide mouseover-like features and true fingernail or thick-glove support in mobile devices.
Can switch dynamically between self-capacitive and mutual-capacitive sensing methods in application enables these differentiating features.

Atmel Corporation has made available its new maXTouch S Series family of touchscreen controllers. The new controller ICs are designed for touchscreen interfaces of up to 17" diagonal for products including smartphones, tablets, digital cameras, e-readers and other applications.

New maXTouch S Series devices include:
mXT224S: a 224-node controller supporting touchscreens from 3.5" to 4.3".
mXT336S: A 336-node controller for larger format superphones similar to Galaxy Note with screens between 4.3" and 5.5" diagonal.
mXT1664S: A high node density, single-chip 32-bit solution targeted at tablet products with touchscreens of 10.1" and above, measured diagonally, and designed to meet the stringent requirements of Windows 8, as well as products based on other operating systems with touchscreens up to 17" diagonal, as per Atmel.

The special features of Atmel's touch screen controllers
maXTouch S Serie use SlimSensor Technology supporting thinner mobiles. SlimSensor cuts display noise up to 3.5V from any type of display, including ACVCOM LCDs and noisier high pixel density displays.

maXTouch S Series controllers support Atmel's recently announced 1mm maXStylus active stylus with multiSense functionality, which enables high-precision, simultaneous touch and stylus input. Lower cost passive stylus with 2mm tip is also supported at over 120Hz report rate.

For a natural user experience, both stylus technologies feature intelligent palm rejection.
A single stylus can be used on all the user's mobile products.

Fully parallelized touch sensor scanning with high report rates
Sensor electrode pitch that is narrower than 4.5mm in common smartphone and tablet screen sizes, for higher touch sensing and stylus tracking resolution that matches increasing display pixel density
Improved touch-processing algorithms, for better finger-tracking precision, improved accuracy and linearity, and more sophisticated rejection of unintended touches

Atmel says with these enablers, maXTouch S Series controllers easily exceed the stringent requirements for touch performance mandated by Microsoft's Windows 8 and Windows Phone 8 operating systems. With stylus support, maXTouch S controllers also enable end-products to take advantage of the latest features of Google's Android 4.0 (Ice Cream Sandwich) operating system.

"The introduction of the maXTouch S Series represents a major milestone for Atmel and a fundamental redefinition of how touchscreen design can be accomplished. Designers of industry-leading touch interface products will no longer have to compromise on touchscreen performance and extreme functionality because of system noise," said Peter Jones, vice president of the microcontroller and touch business unit, Atmel Corporation. "Freed from previous constraints, design engineers now have a technology platform with which they can unleash their creativity and integrate touch interfaces into a new breed of mobile products that will delight consumers. 2012 will be a very exciting time for Atmel and for the industry as a whole."

maXTouch S Series devices are now sampling with lead customers. Production quantities will be available in Q1 2012.