鈩?/div>
C
HARGE
-T
RANSFER
T
OUCH
S
ENSOR
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Less expensive than many mechanical switches
Projects a 鈥榯ouch button鈥?through any dielectric
Turns small objects into intrinsic touch sensors
100% autocal for life - no adjustments required
Only one external part required - a 1壟 capacitor
Piezo sounder direct drive for 鈥榯actile鈥?click feedback
LED drive for visual feedback
2.5 to 5V 20碌A(chǔ) single supply operation
碌
Toggle mode for on/off control (strap option)
10s or 60s auto-recalibration timeout (strap option)
Pulse output mode (strap option)
Gain settings in 3 discrete levels
Simple 2-wire operation possible
HeartBeat鈩?health indicator on output
Active Low (QT110), Active High (QT110H) versions
Vdd
Out
Opt1
Opt2
1
8
Vss
Sns2
Sns1
Gain
QT110
2
3
4
7
6
5
APPLICATIONS -
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Light switches
Industrial panels
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Appliance control
Security systems
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Access systems
Pointing devices
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Elevator buttons
Toys & games
The QT110 / QT110H charge-transfer (鈥淨(jìng)T鈥欌€? touch sensor is a self-contained digital IC capable of detecting near-proximity or touch. It
will project a sense field 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, toys, 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 timeout interval.
The IC requires only a common inexpensive capacitor in order to function. A bare piezo beeper can be connected to create a 鈥榯actile鈥?/div>
feedback clicking sound; the beeper itself then doubles as the required external capacitor, and it can also become the sensing
electrode. An LED can also be added to provide visual sensing indication. With a second inexpensive capacitor the device can
operated in 2-wire mode, where both power and signal traverse the same wire pair to a host. This mode allows the sensor to be wired
to a controller with only a twisted pair over long distances.
Power consumption is under 20碌A(chǔ) in most applications, allowing operation from Lithium cells for many years. In most cases the power
supply need only be minimally regulated.
The IC鈥檚 RISC core employs signal processing techniques pioneered by Quantum; these are specifically designed to make the device
survive real-world challenges, such as 鈥榮tuck sensor鈥?conditions and signal drift. Even sensitivity is digitally determined and remains
constant in the face of large variations in sample capacitor C
S
and electrode C
X
. No external switches, opamps, or other analog
components aside from C
S
are usually required.
The device includes several user-selectable built in features. One, toggle mode, permits on/off touch control, for example for light
switch replacement. Another makes the sensor output a pulse instead of a DC level, which allows the device to 'talk' over the power
rail, permitting a simple 2-wire interface. The Quantum-pioneered HeartBeat鈩?signal is also included, allowing a host controller to
monitor the health of the QT110 continuously if desired. 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
0
0
C to +70
0
C
-40
0
C to +85
0
C
-40
0
C to +85
0
C
0
0
AVAILABLE OPTIONS
SOIC
QT110-S
QT110H-S
QT110-IS
QT110H-IS
8-PIN DIP
QT110-D
QT110H-D
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-
Copyright 漏 1999 Quantum Research Group Ltd
R1.01/0106
Quantum Research Group Ltd
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