AT42QT1111-MU Atmel, AT42QT1111-MU Datasheet - Page 7

• Manufacturer Part Number: AT42QT1111-MU
• Description: IC TOUCH SENSOR 11KEY QFN
• Manufacturer: Atmel
• Series: QTouch™r
• Type: Capacitiver

Specifications of AT42QT1111-MU

• Touch Panel Interface: 10, 2-Wire
• Number Of Inputs/keys: 11 Key
• Data Interface: Serial, SPI™
• Voltage Reference: Internal
• Voltage - Supply: 3 V ~ 5.5 V
• Current - Supply: 12mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN Exposed Pad
• Output Type: Logic
• Interface: SPI
• Input Type: Logic
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AT42QT1111-MU; AT42QT1111-MUTR

2. Overview of the AT42QT1111
2.1
2.2
2.3
2.4
9571A–AT42–02/10
Introduction
Configurations
Guard Channel
Self-test Functions
The AT42QT1111 (QT1111) is a digital burst mode charge-transfer (QT
driver designed for any touch-key applications.
The keys can be constructed in different shapes and sizes. Refer to the Touch Sensors Design
Guide and Application Note QTAN0002, Secrets of a Successful QTouch™ Design, for more
information on construction and design methods (both downloadable from the Atmel
The device includes all signal processing functions necessary to provide stable sensing under a
wide variety of changing conditions, and the outputs are fully debounced. Only a few external
parts are required for operation.
The QT1111 modulates its bursts in a spread-spectrum fashion in order to suppress heavily the
effects of external noise, and to suppress RF emissions.
The QT1111 is designed as a versatile device, capable of various configurations. There are two
basic configurations for the QT1111:
Both configurations allow for a choice of acquisition modes, thus providing a variety of
possibilities that will satisfy most applications (see the following sections for more information).
Additionally, the SYNC line can be used as an external trigger input. Note that in 11-key mode
the SYNC line replaces one key, thus allowing only 10 keys.
See
The device has a guard channel option (available in all key modes), which allows one key to be
configured as a guard channel to help prevent false detection. See
more information.
The QT1111 has two types of self-test functions:
See
• 11-key QTouch. The device can sense up to 11 keys.
• 7-key QTouch with individual outputs for each key. The device can sense up to 7 keys and
• Internal Hardware tests – check for hardware failures in the device’s internal memory.
• Functional checks – confirm that the device is operating within expected parameters.
drive the matching Detect outputs to a user-configurable PWM.
Section 4.7 on page 18
Section 4.10 on page 20
for more information.
for more information.
AT42QT1111-MU/AT42QT1111-AU
Section 4.9 on page 19
™
) capacitive sensor
®
website).
for
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