Integrated piezo haptic driver for realistic HD touchscreen experience

June 03, 2013 // By Graham Prophet
Texas Instruments has introduced a highly-integrated piezo haptic driver for high-definition (HD) consumer, automotive and industrial touchscreen applications.

The DRV2667 features a digital interface, integrated 15-V to 105-V boost converter, power diode, and 40-V to 200-V peak-to-peak (Vpp) fully-differential amplifier, resulting in a complete single-chip solution size that is less than half the size of competitive solutions. The DRV2667 also features an I 2C controlled digital playback engine that relieves the host processor from haptic effects generation. The DRV2667 enables the highest fidelity HD haptic experience for a wide range of products, such as smartphones, tablets, white goods and automotive central information displays.

The integration of digital waveform generation, high-voltage drive, and 2 kB of RAM eliminates the need for external components, and allows the DRV2667 to store and instantly recall haptic waveforms. The driver delivers real-time playback of haptic effects, such as those from Immersion’s TouchSense 5000 haptic effects library. Digital interface and a 2-msec startup enable a faster haptic effect response time, and a more realistic HD tactile experience that closely resembles the feel of specific events, surfaces or effects. Users can experience the pluck of a guitar string, the feel of turning a page, the press of a keyboard or mechanical button, and a myriad of gaming effects.

A high-voltage differential amplifier generates up to 200-Vpp output drive, resulting in six times more vibration force than competing solutions. This capability enables support for a wide range of piezo actuators. Combining the DRV2667 with an external inductor provides the smallest solution size of 10 x 11 mm, which is half the size of competitive solutions that must be paired with an external transformer and other discrete components.

An evaluation kit, DRV2667EVM, costs $99 and includes a fully programmable MSP430G2553 Value Line microcontroller, piezo actuator, sample waveforms and capacitive touch buttons for complete standalone and in-system evaluation. The DRV2667, in a 20-pin, 4 x 4 x 0.9-mm QFN package costs $2.95 (1000).