The MAX11811 low-power touch interface solutions operate from a single 1.7V to 3.6V supply, and target power-sensitive applications such as handheld equipment. The IC includes a 4-wire resistive touch-screen controller, a haptic motor controller plus driver, and an IR proximity-sensing system. The MAX11811 contains a 12-bit SAR ADC and a multiplexer to interface with a 4-wire resistive touch-screen panel. A digital serial interface provides communications.
The MAX11811 includes an advanced state machine, which performs digital preprocessing of the touch-screen measurements, reducing bus loading and application-processor resource requirements. The device enters low-power modes automatically between conversions to save power, making them ideal for portable applications. Also included is a smart interrupt-generation engine, which enables servicing the part only when needed. The register map is compatible with that of the MAX11800/MAX11801.
In addition, the MAX11811 has a built-in haptic controller plus driver to either drive a vibration motor directly, or to interface with an external piezo driver. The built-in haptic waveform generator generates > 50,000 haptic patterns, which are configured through the serial interface. This eliminates the need for a dedicated interface on the applications processor/microcontroller end.
It also contain a general-purpose current DAC output and voltage input. The DAC output can drive IR and visible LEDs; the input can connect to either a photo-detector for proximity sensing, or an ambient light sensor.
Key Features
Applications/Uses
4-Wire Resistive Touch-Screen Interface
X and Y Coordinate and Touch-Pressure Measurement
Ratiometric Measurement
12-Bit SAR ADC
Single 1.7V to 3.6V Supply
Integrated Haptic Controller Driver for ERM and LRA Motors
Integrated Proximity-Sensing System
General-Purpose Current DAC Output and General-Purpose Input
PWM Output for Piezo Drivers
Data Tagging Provides Measurement and Touch-Event Information
Data Filtering Reduces Noise
Aperture Mode Provides Spatial Filtering
Digital Preprocessing Reduces Serial Bus Activity and Interrupt Generation
Programmable Touch-Detect Pullup Resistor
Auto Power-Down Control for Ultra-Low-Power Operation
400kHz I2C Interface
2.1mm x 2.1mm, 16-Pin WLP and 4mm x 4mm, 20-Pin TQFN Packages
Low-Power Operation
246µW at VDD = 1.8V, 34.4ksps
698µW at VDD = 3.6V, 34.4ksps
Automotive Centre consoles
Handheld Games
Mobile Communication Devices
PDA, GPS, Media Players, Portable Navigation Devices
