QT" touch chip cuts cost of iPod-style rotary sensors by over 60 percent

Citation

(2005), "QT" touch chip cuts cost of iPod-style rotary sensors by over 60 percent", Sensor Review, Vol. 25 No. 3. https://doi.org/10.1108/sr.2005.08725caf.002

"QT" touch chip cuts cost of iPod-style rotary sensors by over 60 percent

"QT" touch chip cuts cost of iPod-style rotary sensors by over 60 percent

Keywords: Sensors

Quantum Research Group, the charge- transfer (QT) capacitive touch company, has announced the QT510 QWheel IC, a chip that the company believes will cut the cost of rotary touch sensing by 60 per cent in consumer electronic products. In high volume, existing rotary capacitive solutions cost around US$5 but implementing a touch wheel based on QWheel technology will cut the cost to under US$3. In many cases the technology is less expensive than mechanical equivalents, and in all cases is more reliable with high consumer demand.

QWheel touch technology can be thought of as a “capacitive potentiometer”, where the wiper is a human finger. The electrode consists of a simple resistive ring element which can be placed behind any dielectric panel. Three capacitive QT channels are connected to this ring and the signals processed to 7-bits of absolute position. Output is via a standard SPI serial interface. No external active components are needed and the 14-pin device operates from a single 2.5 to 5V supply. The device is in a lead-free SOIC or TSSOP package.

The QWheel can sense through panels up to 3mm thick, and even through gloves. When placed behind glass or plastic, the circuit creates a smooth, sealed, indestructible rotary touch control that can replace virtually any mechanical encoder or potentiometer. It does not require a hole or knob and therefore, has no service or maintenance problems.

The QT510 uses spread-spectrum modulation for high noise resistance and low RF emissions. It features drift compensation to account for slow changes due to aging or changing environmental conditions. The part will also operate in a low power mode, consuming as little as 10μA in sleep mode. An unique proximity mode allows the device to detect hand movement up to 50mm away from the panel surface; this can be made to activate a display or product from standby, before the user even touches the product.

QWheel is a reliable, cost-saving alternative to existing capacitive sensing technologies and can also be used wherever a mechanical control would otherwise be employed. Applications include menu selection, volume, lighting, position, temperature, and speed controls. Market sectors include consumer electronics and appliances, audio, HVAC controls, communications, toys and games, industrial controls, aerospace, military and automotive controls.

The QT510 QWheel chip can be assessed using Quantum's E510 evaluation board. The E510 includes an interface converter to connect it to a PC, plus PC display software. The E510 PCB comes fully assembled and tested ready for adhering to the supplied plastic demo panel or to the inside of the user's end product. It costs US$95 through distributors.

The QT510 QWheel chip is available now priced at US$2.5 each for 100k quantities (Plate 2).

Plate 2 The QT 510 QWheel IC

For further information contact: George East, Quantum Research Group Limited, 1 Mitchell Point, Ensign Way, Hamble, Southampton, SO31 4RF, UK. Tel.: +44 (0) 2380 565600; Fax: +44 (0) 2380 453939; E-mail: george.east@qprox.com; Web site: www.qprox.com