AT42QT2161-MMU Atmel, AT42QT2161-MMU Datasheet - Page 6

• Manufacturer Part Number: AT42QT2161-MMU
• Description: IC TOUCH SENSOR 16KEY QFN M-MOD
• Manufacturer: Atmel
• Type: Capacitiver

Specifications of AT42QT2161-MMU

• Touch Panel Interface: 8, 2-Wire
• Number Of Inputs/keys: 16 Key, Slider
• Resolution (bits): 10 b
• Data Interface: I²C, Serial
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 1.14mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.2
2.3
6
Keys and Slider
Enabling/Disabling Keys
AT42QT2161
Figure 2-1.
The QT2161 is capable of a maximum of 16 keys. These can be located anywhere within an
electrical grid of 8X and 2Y scan lines.
A lesser number of enabled keys will cause any unused acquisition burst timeslots to be pared
from the sampling sequence, to optimize acquire speed and lessen power consumption. Thus, if
only 8 keys are actually enabled, only 8 timeslots are used for scanning.
Additional processing can be done on the keys to form a slider. The slider will have to start at X0
and use only Y0. The slider can consist of a minimum of 2 keys and a maximum of 8 keys.
Keys can be enabled by setting a nonzero burst length. A zero burst length disables the key.
The QT2161 includes all signal processing functions necessary to provide stable
sensing under a wide variety of changing conditions. Only a few external parts are
required for operation. The entire circuit can be built within a few square
centimeters of single-sided PCB area. CEM-1 and FR1 punched, single-sided
materials can be used for the lowest possible cost. The PCB’s rear can be mounted
flush on the back of a glass or plastic panel using a conventional adhesive, such as
3M VHB two-sided adhesive acrylic film.
The device uses an
to permit individual key parameter setup. The command structure is designed to
minimize the amount of data traffic while maximizing the amount of information
conveyed.
In addition to normal operating and setup functions the device can also report back
actual signal strengths.
Field Flow Between X and Y Elements
I
2
C
-compatible interface to allow key data to be extracted and
element
X
overlying panel
elem ent
Y
9614A–AT42–08/10