QT401 Datasheet, PDF (1/16 Pages) Quantum Research Group – QSLIDE TOUCH SLIDER IC

lQ
QT401
QSLIDE™ TOUCH SLIDER IC
z 1-dimensional finger-touch slider
z Extremely simple circuit - no external active components
z Completely passive sensing strip: no moving parts
z Compatible with clear ITO over LCD construction
z SPI slave-mode interface
z Self-calibration and drift compensation modes
z Proximity mode for wake up of a product
z Spread-spectrum operation for optimal EMC compliance
z 2.5 - 5.5V single supply operation; very low power
z 14-pin SOIC, TSSOP lead-free packages
z Inexpensive, simple 1-sided PCB construction possible
z E401 reference design board available
VDD
SDO
/SS
SCLK
SDI
SNS1A
SNS1B
1
14
2
13
3 QT401 12
4
11
5
10
6
9
7
8
GND
DRDY
DETECT
PROX
N/A
SNS2A
SNS2B
APPLICATIONS
y Lighting controls
y Appliance controls
y Touch-screens
y 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.
TA
-40⁰C ~ +85⁰C
LQ
AVAILABLE OPTIONS
SO-14
QT401-ISG
TSSOP-14
QT401-ISSG
Copyright © 2004 QRG Ltd
QT401 R10.04/0505