19-5133; Rev 0; 1/10
EVALUATION KIT
AVAILABLE
TacTouch™, Low-Power, Ultra-Small, Resistive
Touch-Screen Controller with Haptic Driver
General Description
The MAX11811 low-power touch-screen controller operates from a 1.7V to 3.6V single supply targeting powersensitive applications such as handheld equipment. The
device contains a 12-bit SAR ADC and a multiplexer to
interface with a resistive touch-screen panel. A digital
serial interface provides communications.
The MAX11811 includes digital preprocessing of the
touch-screen measurements, reducing bus loading
and application processor (AP) resource requirements.
The included smart interrupt function generator greatly
reduces the frequency of interrupt servicing to the devices. The MAX11811 enters low-power mode automatically
between conversions to save power, making the device
ideal for portable applications.
The MAX11811 offers two modes of operation: direct
and autonomous. Direct mode allows the application
processor to control all touch-screen controller activity. Autonomous mode allows the MAX11811 to control
touch-screen activity, thereby freeing the application
processor to perform other functions. In autonomous
mode, the device periodically scans the touch screen
for a touch event without requiring host processor
intervention. This can be used to reduce system power
consumption. An on-chip FIFO is used during autonomous mode to store results and increase effective data
throughput and lower system power.
The MAX11811 supports data-tagging, which records
the type of measurement performed; X, Y, Z1, or Z2, and
the type of touch event; initial touch, continuing touch, or
touch release.
The MAX11811 features a haptic driver to either drive a
vibration motor directly or to interface with an external
piezo actuator driver. The device generates PWM signals that can drive the MAX11835 haptic piezo controller. The device includes a general-purpose current DAC
output and a general-purpose input that can be used to
drive IR and visible LEDs, as well as IR photo-detectors
in applications such as proximity detectors.
2
The MAX11811 supports the I
MAX11811ETP+ is available in a 20-pin TQFN package
and is specified over the extended industrial temperature range of -40NC to +85NC. The MAX11811GTP/V+ is
specified over the -40NC to +105NC automotive temperature range.
Ordering Information and Typical Operating Circuits nnm,
nappear at end of data sheet.
TacTouch is a trademark of Maxim Integrated Products, Inc.
C serial bus. The
Features
4-Wire Touch-Screen Interface
S
X/Y Coordinate Measurement and Touch Pressure
S
Measurement
Ratiometric Measurement
S
12-Bit SAR ADC
S
Single 1.7V to 3.6V Supply
S
Two Operating Modes—Direct and Autonomous
S
Data Tagging Provides Measurement and Touch
S
Event Information
Data Filtering Provides Noise Reduction
S
Aperture Mode Provides Spatial Filtering
S
Digital Processing Reduces Bus Activity and
S
Interrupt Generation
Programmable Touch-Detect Pullup Resistors
S
Auto Power-Down Control for Low-Power
S
Operation
General-Purpose Current DAC Output
S
General-Purpose Input
S
Integrated Proximity Sensing System
S
Integrated Motor Haptic Driver*
S
PWM Output for MAX11835 Haptic Piezo
S
Controller
400kHz I
S
20-Pin, 4mm x 4mm TQFN
S
Low-Power Operation
S
250µW at V
ESD Protection
S
Q8kV HBM (X+, X-, Y+, Y-)
†
(HPC)
2
C Interface
= 1.7V, 34.4ksps
DD
Applications
Mobile Communication Devices
PDA, GPS Receivers, Personal Navigation
Devices, Media Players
Digital Still Camera
Digital Video Camera
Digital Photo Frame
POS Terminals and Financial Terminals
Handheld Games
Automotive Center Consoles
*Use of Haptic technologies in an end product may require
third-party licensing.
†
Quickview available.
MAX11811
_______________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.