QT411

      With the help of Quantum's patented charge-transfer ('QT') methods,the QUANTUM company make the QT411 QSlide™ IC,which is a new type of linear capacitive touch 'slider' sensor IC. This unique IC allows designers to do a lot of things.For example,the users could create speed or volume controls, menu bars, and other more exotic forms of human interface on the panel of an appliance or personal electronic device.Through a completely sealed panel,it can be generally used to replace any form of linear control.And also the QT411 is significantly more stable with temperature and other environmental influences.That's the upgrade of  QT401 which made before.In some particular situation QT411 can tolerate extreme temperature swings without false detection or shifts in reported touch position.And also if meet the the endpoints of the slider area it does not require special calibration of this.
      QT411 has four applications.The first one is personal electronics.The second one is appliance controls.The third one is climate controls.The last one is automotive controls.Also it has twelve features.The first one is QT401 QSlide™ enhancement - simplified calibration.The second is linear finger-touch capacitive slider control.The third one is robust charge-transfer sensing method.The fourth one is extremely simple circuit - no external active components.The fifth one is SPI slave-mode interface.The sixth one is self-calibration and drift compensation.The seventh one is spread-spectrum operation for optimal EMC compliance.The eighth one is 2.5 - 5.5V single supply operation,very low power.The ninth one is enhanced power supply & thermal drift rejection.The tenth one is 14-pin TSSOP Pb-free package.The eleventh is compatible with clear ITO over LCD construction.The last one is inexpensive, simple 1-sided PCB construction possible.
      Some absolute maximum ratings of QT411 have been concluded as seven points.The first one is that the operating temperature range(Ta) should be within  -40 and +85°C.The second one is that the Storage temperature range(Ts) should be within -55 and +125°C.The third one is Vdd should be within -0.5 and +7.0V.The fourth one is about the max continuous pin current(any control or drive pin) should be ±20mA.The fifth one is about short circuit duration to ground(any pin) could be infinite.The sixth one is about short circuit duration to VDD(any pin) also could be infinite.The seventh is about voltage forced onto any pin,which should be within -0.6V to (Vdd + 0.6) Volts.
      Attention for these important notes.When in the sleep mode,you should note that activity on SCLK will also wake the QT411, and it willthen in turn wait for the /SS to rise. If you want to have the lowest possible operation in sleep mode, do not pulse on SCLK until after /SS goes low.The second point you should to note is that with the detect output pin in the QT411 detection occurs when one or two of the sensing channels becomes imbalanced with respect to the other channel(s).And a touch at one position will always cause such an imbalance.