LQ
QP
ROX
™
QT320
2-C
HANNEL
P
ROGAMMABLE
A
DVANCED
S
ENSOR
IC
Two channel digital advanced capacitive sensor IC
Projects two ‘touch buttons’ through any dielectric
Cloning for user-defined sensing behavior
100% autocal - no adjustments required
Only one external capacitor per channel
User-defined drift compensation, threshold levels
Variable gain via Cs capacitor change
Selectable output polarities
Toggle mode / normal mode outputs
HeartBeat™ health indicator on outputs (can be disabled)
1.8 ~ 5V supply, 60µA
APPLICATIONS
Light switches
Industrial panels
Appliance control
Security systems
Access systems
Pointing devices
Computer peripherals
Entertainment devices
The QT320 charge-transfer (“QT’”) touch sensor chip is a self-contained digital IC capable of detecting near-proximity or
touch on two sensing channels. It will project sense fields through almost any dielectric, like glass, plastic, stone, ceramic,
and most kinds of wood. It can also turn small metal-bearing objects into intrinsic sensors, making them respond to proximity
or touch. This capability coupled with its ability to self calibrate continuously can lead to entirely new product concepts.
It is designed specifically for human interfaces, like control panels, appliances, security systems, lighting controls, or
anywhere a mechanical switch or button may be found; it may also be used for some material sensing and control
applications provided that the presence duration of objects does not exceed the recalibration time-out interval.
The IC requires only a common inexpensive capacitor per channel in order to function.
Power consumption and speed can be traded off depending on the application; drain can be as low as 60µA, allowing
operation from batteries.
The IC’s RISC core employs signal processing techniques pioneered by Quantum; these are specifically designed to make
the device survive real-world challenges, such as ‘stuck sensor’ conditions and signal drift. Even sensitivity is digitally
determined. All key operating parameters can be set by the designer via the onboard eeprom which can be configured to alter
sensitivity, drift compensation rate, max on-duration, output polarity, and toggle mode independently on each channel.
No external switches, opamps, or other analog components aside from Cs are usually required.
The Quantum-pioneered HeartBeat™ signal is also included, allowing a host controller to monitor the health of the QT320
continuously if desired; this feature can be disabled via the cloning process.
By using the charge transfer principle, the IC delivers a level of performance clearly superior to older technologies in a highly
cost-effective package.
T
A
0 C to +70 C
-40
0
C to +85
0
C
0
0
AVAILABLE OPTIONS
SOIC
-
QT320-IS
8-PIN DIP
QT320-D
-
LQ
Copyright © 2002 QRG Ltd
QT320/R1.03 08/02
QUANTUM [ QUANTUM RESEARCH GROUP ]
