Atmel AT42QT2160触摸控制方案

Atmel公司的AT42QT2160触摸控制器,在单片内集成了触摸键和触摸滑动功能. AT42QT2160能控制多达16个触摸键,并能通过PWM输出能控制多达11个LED,从而不需要外接LED控制器,因此广泛应用在笔记本电脑,移动手机和移动设备,家用电器和PC外设等.本文介绍了AT42QT2160的主要特性,电路连接方框图以及评估板EVK2160A的性能和详细电路图.

The AT42QT2160-MMU (QT2160) is designed for use with up to 16 keys and a slider
(constructed from 2 keys up to 8 keys). There are three dedicated General Purpose
Input/Outputs (GPIOs) which can be used as inputs for mechanical switches etc. or as driven outputs. There are eight shared General Purpose Outputs (GPOs) (X0...X7) which are driven outputs only. There is PWM control for all GPIO/GPOs.

The QMatrix™ technology employs transverse charge-transfer sensing electrode designs which can be made very compact and are easily wired. Charge is forced from an emitting electrode into the overlying panel dielectric, and then collected on a receiver electrode. This directs the charge into a sampling capacitor which is then converted directly to digital form, without the use of amplifiers.

The keys are configured in a matrix format that minimizes the number of required scan
lines and device pins. The key electrodes can be designed into a conventional Printed
Circuit Board (PCB) or Flexible Printed Circuit Board (FPCB) as a copper pattern, or
as printed conductive ink on plastic film.

AT42QT2160主要特性:
Number of keys: up to 16 keys, and one slider (constructed from 2 to 8 keys)
Number of I/O lines: 11 (3 dedicated - configurable for input or output, 8 shared -output only), PWM control for LED driving
Technology: patented spread-spectrum charge-transfer (transverse mode)
Key outline sizes: 6 mm x 6 mm or larger (panel thickness dependent); widely different sizes and shapes possible
Key spacings: 8 mm or wider, center to center (panel thickness dependent)
Slider design: 2 to 8 keys placed in sequence, same design as keys
Electrode design: two-part electrode shapes (drive-receive); wide variety of possible layouts
PCB layers required: one layer (with jumpers), two layers (no jumpers)
Electrode materials: PCB, FPCB, silver or carbon on film, ITO on film
Panel materials: plastic, glass, composites, painted surfaces (low particle density metallic paints possible)
Adjacent metal: compatible with grounded metal immediately next to keys
Panel thickness: up to 3 mm glass, 2.5 mm plastic (key size dependent)
Key sensitivity: individually settable via simple commands over I2C-compatible interface
Interface: I2C-compatible slave mode (100kHz)
Moisture tolerance: best in class
Power: 1.8 V to 5.5 V
Package: 28-pin 4 x 4 mm MLF RoHS compliant
Signal processing: self-calibration, auto drift compensation, noise filtering, Adjacent Key SuppressionTM technology
Applications: laptop, mobile, consumer appliances, PC peripheral etc.
Patents: AKS (patented Adjacent Key Suppression™) technology QMatrix (patented charge-transfer method) QSlide (patented charge-transfer method) (patent-pending QSlide sensing configuration)
This datasheet is applicable to revision 4R0 chips only



图1. AT42QT2160连接方框图

评估板EVK2160A:
This kit is for the evaluation and development of applications using the AT42QT2160-MMU (QT2160) 16 Key QMatrixTM Integrated Circuit (IC). In this example, the QT2160 is shown working in a battery powered Standalone mode, but can connected to a PC and/or User application by simple modifications to the EVK2160A Evaluation Board.



图2.评估板外形图



图3.评估板EVK2160A电路图(1)



图4.评估板EVK2160A电路图(2)