mXT640U 1.1
maXTouch 640-node Touchscreen Controller
Product Brief
Description
The mXT640U uses a unique charge-transfer acquisition engine to implement Microchip’s patented capacitive sensing method.
Coupled with a state-of-the-art CPU, the entire touchscreen sensing solution can measure, classify and track a number of
individual finger touches with a high degree of accuracy in the shortest response time. The mXT640U allows for both mutual and
self capacitance measurements, with the self capacitance measurements being used to augment the mutual capacitance
measurements to produce reliable touch information.
maXTouch
®
Adaptive Sensing Touchscreen
Technology
• Up to 32 X (transmit) lines and 20 Y (receive) lines
• A maximum of 640 nodes can be allocated to the
touchscreen
• Touchscreen size 8.17 inches (16:10 aspect ratio),
assuming a sensor electrode pitch of 5.5 mm. Other
sizes may be possible with different electrode pitches
and appropriate sensor material
• Multiple touch support with up to 16 concurrent
touches tracked in real time
• Dual-boot OS support for Microsoft
®
Windows
®
and
Android
Touch Sensor Technology
• Discrete/out-cell support including glass and PET film-
based sensors
• On-cell/touch-on display support including TFT, IPS
and OLED
• Synchronization with display refresh timing capability
• Support for standard (for example, Diamond) and
proprietary sensor patterns (review of designs by
Microchip recommended)
• Glove Support
- Multiple-finger glove touches up to 1.5 mm
thickness (subject to stack-up design)
- Single-finger glove touch up to 5 mm thickness
(subject to stack-up design)
• Mutual capacitance and self capacitance
measurements supported for robust touch detection
• Noise suppression technology to combat ambient,
charger noise, and power-line noise
- Up to 240 Vpp between 1 Hz and 1 kHz
sinusoidal waveform
- Up to 20 Vpp between 1 kHz and 1 MHz
sinusoidal waveform
• Stylus Support
- Supports passive stylus with 1 mm contact
diameter, subject to configuration, stack up, and
sensor design
• Scan Speed
- Up to 250 Hz one finger reporting rate, subject to
configuration
- Typical report rate for 10 touches
100
Hz
(subject to configuration)
- Initial touch latency <20 ms for first touch from
idle, subject to configuration
- Configurable to allow for power and speed
optimization
Front Panel Material
• Works with PET or glass, including curved profiles
(configuration and stack-up to be approved by
Microchip)
• Glass 0.4 mm to 4.5 mm, dependent on screen size,
touch size and stack-up
• Plastic 0.2 mm to 2.2 mm, dependent on screen size,
touch size and stack-up
On-chip Gestures
• Supports wake up/unlock gestures, including symbol
recognition
Keys
• Up to 32 nodes can be allocated as mutual
capacitance sensor keys (subject to other
configurations)
• Support for 3 Generic Keys in addition to the
touchscreen array (subject to other configurations)
• Adjacent Key Suppression (AKS) technology is
supported for false key touch prevention
Touch Performance
• Moisture/Water Compensation
- No false touch with condensation or water drop up
to 22 mm diameter
- One-finger tracking with condensation or water
drop up to 22 mm diameter
2017 Microchip Technology Inc.
Product Brief
DS400001942A-page 1
MXT640U 1.1
Enhanced Algorithms
• Lens bending algorithms to remove display noise
• Touch suppression algorithms to remove unintentional large touches, such as palm
• Palm Recovery Algorithm for quick restoration to normal state
Product Data Store Area
• Up to 32 bytes of user-defined data can be stored during production
Power Saving
• Programmable timeout for automatic transition from active to idle states
• Pipelined analog sensing detection and digital processing to optimize system power efficiency
Application Interfaces
• I
2
C-compatible slave mode: Standard/Fast mode 400 kHz, Fast-mode Plus 1 MHz, High-speed mode up to
3.4 MHz
• HID-I
2
C interface for Microsoft
®
Windows
®
8.x and later versions
• Interrupt to indicate when a message is available
• SPI Debug Interface to read the real-time raw data for tuning and debugging purposes
Power Supply
•
•
•
•
•
Digital (Vdd) 3.3 V nominal
Digital I/O (VddIO) 3.3 V nominal
Analog (AVdd) 3.3 V nominal
High voltage internal X line drive (XVdd) 6.6 V with internal voltage pump
High voltage internal X line drive (XVdd) 9.9 V with internal voltage pump
Packages
• 88-ball UFBGA 6 × 6 × 0.6 mm, 0.5 mm pitch
• 88-ball X1FBGA 6 × 6 × 0.45 mm, 0.5 mm pitch
Operating Temperature
• –40C to +85C
DS400001942A-page 2
Product Brief
2017 Microchip Technology Inc.
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