lQ
QT401
QS
LIDE
™ T
OUCH
S
LIDER
IC
1-dimensional finger-touch slider
Extremely simple circuit - no external active components
Completely passive sensing strip: no moving parts
Compatible with clear ITO over LCD construction
SPI slave-mode interface
Self-calibration and drift compensation modes
Proximity mode for wake up of a product
Spread-spectrum operation for optimal EMC compliance
2.5 - 5.5V single supply operation; very low power
14-pin SOIC, TSSOP lead-free packages
Inexpensive, simple 1-sided PCB construction possible
E401 reference design board available
VDD
SDO
/SS
SCLK
SDI
SNS1A
SNS1B
1
2
3
4
5
6
7
14
13
GND
DRDY
DETECT
PROX
N/A
SNS2A
SNS2B
QT401
12
11
10
9
8
APPLICATIONS
Lighting controls
Appliance controls
Touch-screens
Automotive controls
The QT401 QSlide™ IC is a 1-dimensional position sensor IC designed for human interfaces. This unique IC allows designers
to create speed or volume controls, menu bars, and other more exotic forms of human interface on the panel of an appliance
or over an LCD display.
The device uses a simple, inexpensive resistive sensing strip between two connection end points. The strip element can be an
arc or a semicircle or simply linear. The strip can also be used as a proximity sensor out to several centimeters, to wake up an
appliance or display from a sleep mode in a dramatic fashion.
The QT401 can report a single rapid touch anywhere along the slider element, or, it can track a finger moving laterally along
the slider strip in real time. The device self-calibrates under command from a host controller in one of two modes.
The QT401 is a new type of capacitive sensor based on Quantum’s patented charge-transfer methods. This device uses two
channels of simultaneous sensing across a resistive element to determine finger position, using mathematical analysis. The
accuracy of QSlide™ is theoretically the same as a conventional potentiometer. A positional accuracy of 5% (or better) is
relatively easy to achieve.
The acquisitions are performed in a burst mode which uses proprietary spread-spectrum modulation for superior noise
immunity and low emissions.
The output of the QT401 can also be used to create discrete controls on a strip, by interpreting sets of number ranges as
buttons. For example, the number range 0..19 can be button A, 30..49 button B, 60..79 button C etc. Continuous slider action
and discrete controls can be mixed on a single strip, or, the strip can be reinterpreted differently at different times, for example
when used below or on top of an LCD to act as a menu input device that dynamically changes function in context. In this
fashion the QT401 can be used to create ultra-simple, extremely inexpensive ‘touch screens’. The device is compatible with
ITO (Indium Tin Oxide) overlays on top of various displays.
T
A
-40 C ~ +85 C
0
0
AVAILABLE OPTIONS
SO-14
QT401-ISG
TSSOP-14
QT401-ISSG
LQ
Copyright © 2004 QRG Ltd
QT401 R10.04/0505
QUANTUM [ QUANTUM RESEARCH GROUP ]
