qt60320d Quantum Research Group, qt60320d Datasheet
qt60320d
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qt60320d Summary of contents
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... Security keypanels Industrial keyboards The QT60320D digital charge-transfer (“QT”) QMatrix™ designed to detect touch keys in a scanned X-Y matrix. It will project the keys through almost any dielectric, like glass, plastic, stone, ceramic, and even most kinds of wood thicknesses more ...
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... OVERVIEW The QT60320D is a digital burst mode charge-transfer (QT) sensor designed specifically for matrix geometry touch controls; it includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions. Only a few low cost external parts are required for operation. The entire circuit can be built within about 1 square inch of PCB area (smt) ...
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... Y lines, since stray C from Y to ground appears merely as a parallel capacitance to a much larger value of Cs. The QT60320D circuit design maintains high gain levels independent stray coupling C to ground. It also readily compensates for field-related issues like electrode design or the composition of the overlying panel has individual programmable gain and threshold settings for each key ...
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... Since key touches result in negative signal swings, the threshold is set below the signal reference level. The QT60320D employs a hysteresis of 25% of the delta between the reference and threshold levels. The signal must rise by 25% of the distance from threshold to reference before the detection event drops out and the key registers as untouched ...
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... CIRCUIT SPECIFICS A basic QT60320D circuit is shown in Figure 2-1. 2.1 SIGNAL PATH The QT60320D requires an external sampling capacitor, two Cz capacitors, an amplifier, some analog switches, and an R2R ladder DAC to operate. The Cs capacitor performs the charge integration function by collecting charge coupled though a selected key during the dV/dt of the rising edge of an 'X' scan line ...
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... X pins are used to drive the external R2R ladder network which generates an offset to the amplifier chain during this period that the amplifier stabilizes and the signal is sampled internally by the QT60320D. Figure 2-3 also shows a dwell-adjusted version of Yb, Yb', that can be generated with the help of external timing delays. ...
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... Cs to ground. 3 SERIAL INTERFACE The QT60320D uses a serial interface to a host. This port uses a simple ASCII protocol described in this section. 3.1 SERIAL PORT SPECIFICATIONS The QT60320D uses a full-duplex asynchronous serial ...
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... If the power supply is shared with another electronic system, care should be taken to assure that the supply is free of digital spikes, sags, and surges which can adversely affect the circuit. The QT60320D will track slow changes in Vcc, but it can be adversely affected by rapid voltage steps and impulse noise on the supply rail. ...
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... To reduce leakage current problems the amplifier should be a JFET or CMOS input type only. 4.6 ESD PROTECTION In general the QT60320D will be protected from direct static discharge by the overlying panel. However, even with a panel, transients can still flow into the electrode via induction extreme cases, via dielectric breakdown ...
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... F4.com = !(ys4 & !xsd); " enables to 3125 are active low F3.com = !(ys3 & !xsd); F2.com = !(ys2 & !xsd); F1.com = !(ys1 & !xsd The EPLD functions to generate control signals for the QS3125 quad n-channel switch, to POLARITY OUTPUT_TYPE Feed_Pin ) Feed_Pin ) Feed_Pin ) Feed_Pin ) Feed_Pin ) 10 FEEDBACK_TYPE ) QT60320D R1.11/12.07.03 ...
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... E6S3 BOARD SCHEMATIC LQ 11 QT60320D R1.11/12.07.03 ...
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... High input logic level HL V Low output voltage OL V High output voltage Input leakage current A R Acquisition resolution LQ Min Typ Max 25 0.8 2.2 0.6 Vdd-0.7 ± +105 +125 Units Notes 4mA sink V 1mA source µA bits QT60320D R1.11/12.07. ...
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... TQFP A 0 QT60320D- Inches Min Max Notes 0.386 0.394 SQ 0.458 0.478 SQ 0.003 0.008 0.018 0.030 0.002 0.006 - 0.047 0.012 0.018 0.031 0.031 BSC 0.315 0.315 BSC 0 7 Marking QT60320D-A QT60320D R1.11/12.07.03 ...
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Tel: +44 (0)23 8056 5600 Fax: +44 (0)23 8045 3939 The specifications set out in this document are subject to change without notice. All products sold and services supplied by QRG are subject to our Terms and Conditions of ...