Date: 29th Jan 2010

Haptic piezo controller for touch-screen and touch-button apps

Maxim has introduced the MAX11835, a new high integrated, programmable TacTouch HPC (haptic piezo controller) for single-layer and multilayer piezo actuators. The MAX11835 with built-in haptic waveform generation reduces processor load and improves haptic response time, and suitable for touch-screen and touch-button applications such as cell phones, MIDs (mobile Internet devices), MP3 players, portable media players, digital photo frames, multifunction printers, digital still/video cameras, and POS (point-of-sale) terminals.

The MAX11835 generates any type of user-programmable waveforms including sine, trapezoidal, square, and pulse to drive the piezo loads to create custom tactile sensations. The low-power MAX11835 directly interfaces with application processor/host controllers through a standard serial interface and integrates various blocks such as a boost regulator, pattern storage memory, and waveform generator block in one package to provide complete piezo driver solution.
The key features of the MAX11835 haptic piezo controller are,

Create custom user-programmable waveforms with up to 8-bit resolution
On-chip DC boost regulator
On-chip 33V high-voltage boost switch with programmable maximum peak current
Flyback converter generates piezo high-voltage supply
On-chip haptic multiple waveform storage
TRIGb to optionally start a preprogrammed waveform
DISb to disable or enter low power-boost operation during a PA burst
1.8V to 3.6V of digital supply
2.7V to 5.25V boost/flyback and Analog Power Supply (VBATT)
Programmable low-power modes
1µA of deep-sleep shutdown current
Thermal shutdown
Available in a 400kHz I2C serial interface
±2kV HBM, ±1kV CDM, ±200V MM ESD protection

Maxim says Single-layer piezo actuators require high voltage drives of up to 250V, Multilayer piezo actuators require up to 40V and thus eliminate additional high-voltage safety requirements in (handheld) products. Multilayer piezo actuators also support audio output, but are more expensive than single-layer piezo actuators.

By integrating a user-programmable haptic pattern generator, programmable boost converter, and high-voltage, high capacitive load driver, the MAX11835 generates a user-configurable, slew-rate-limited, boosted voltage output.

The MAX11835 output drivers are able to drive high capacitive loads, allowing the connection of multiple piezo actuators to a single device. This reduces total system cost, since only one IC is required in many applications.

Package: 25-pin WLP package
Price: Starts at $1.40 for 1k pieces
Availability: Now in samples

For more details visit www.maxim-ic.com