at42qt1040 ATMEL Corporation, at42qt1040 Datasheet
at42qt1040
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at42qt1040 Summary of contents
Page 1
... Signal Processing: – Self-calibration, auto drift compensation, noise filtering, Adjacent Key Suppression technology • Applications: – Mobile, consumer, white goods, toys, kiosks, POS, and so on ™ ™ (AKS ) technology to enable accurate key ™ QTouch 4-key Sensor IC AT42QT1040 9524B–AT42–04/09 ...
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... OD 14 OUT2 OD 15 SNSK3 I/O 16 SNS3 I/O 17 N/C – 18 N/C – 19 N/C – 20 SNSK2 I/O * Option resistor should always be fitted even if channel is unused and Cs capacitor is not fixed. I/O CMOS input and output AT42QT1040 SNSK3 SNS2 1 OUT2 2 14 QT1040 13 OUT3 SNS1 3 12 OUT1 4 11 OUT0 SNS0 ...
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... SNSK1 SNS1 QT1040 SNSK2 6 N/C SNS2 7 N/C 10 N/C SNSK3 17 N/C SNS3 18 N/C 19 N/C check the following sections for component values capacitors (Cs0 – Cs3) 7: Voltage levels 6: LED traces AT42QT1040 J1 VDD 1 RAKS 2 3 AKS SELECT J2 VDD 1 RFS 2 3 SPEED SELECT Rs0 4 Cs0 5 Rs1 2 Cs1 3 Rs2 ...
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... Overview of the AT42QT1040 2.1 Introduction The AT42QT1040 (QT1040 digital burst mode charge-transfer (QT driver designed for touch-key applications. The device can sense from one to four keys; one to three keys can be disabled by not installing their respective sense capacitors. Any of the four channels can be disabled in this way. ...
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... To prevent this, the sensor includes a timer known as the Max On-duration feature which monitors detections detection exceeds the timer setting, the sensor performs an automatic recalibration. Max On-duration is set to ~30s. 9524B–AT42–04/09 for more information). When AKS is disabled, any combinations of AT42QT1040 5 ...
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... Modern no-clean flux is generally compatible with capacitive sensing circuits PCB is reworked in any way, clean it thoroughly to remove all traces of the flux residue around the capacitive sensor components. Dry it thoroughly before any further testing is conducted. AT42QT1040 6 ™ Design, and the Touch Sensors Design Guide, both downloadable from ...
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... A single ceramic 0.1 µF bypass capacitor, with short traces, should be placed very close to the power pins of the IC. Failure can result in device oscillation, high current consumption, erratic operation, and so on. Examples of Good and Bad Tracking Example of GOOD tracking AT42QT1040 Figure 3-1 shows an example of Example of BAD tracking 7 ...
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... LEDs to a power supply other than Vdd; if the LED supply is higher than Vdd it may cause erratic behavior of the QT1040 and “back-power” the QT1040 through its I/O pins. AT42QT1040 8 RAKS Resistor Changing the RAKS option will affect the sensitivity of the particular key ...
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... The RFS resistor should always be connected to either Vdd or Vss and not changed during operation of the device. Changing the RFS option will affect the sensitivity of the particular key. Always check that the sensitivity is suitable after a change. Retune Cs1 if necessary. AT42QT1040 Pulse on OUT2 Mode Fast mode ...
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... The serial data is clocked out at a rate of ~200 kHz, MSB first Table 4-3. AT42QT1040 10 If the short is not removed within 5 seconds, debug mode is still entered, but with Channel 3 unusable until a re-calibration occurs. Note that as Channel 3 will show up as being in detect, a recalibration will occur after Max On-duration (~30 seconds) ...
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... Contains the number of keys active Show the touch status of the corresponding keys to Figure 4-5 show the usefulness of the debug data out feature. Channels can be Byte Clocked Out (~5 µs Period) AT42QT1040 Notes Signed 16-bit integer Signed 16-bit integer Signed 16-bit integer Signed 16-bit integer ...
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... Figure 4-3. Figure 4-4. Figure 4-5. AT42QT1040 12 Byte Following Byte (~ 30 µs Period) Full Debug Send (30 Bytes) Debug Lines Floating Between Debug Data Sends (30 Bytes Send) 9524B–AT42–04/09 ...
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... Volts -40°C to +85°C -55°C to +125°C 1.8V to 5.5V ±20 mV maximum Min Typ Max -0.5V – 0.3V 0.6 Vdd Vdd Vdd + 0.5V 0 – 0.7 0.8 Vdd – Vdd – <0. – 50 AT42QT1040 Units Notes sink current source current µA k 13 ...
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... Timing Specifications Parameter Description T Burst duration BS Fc Burst center frequency Fm Burst modulation, percentage T Burst pulse width PW 5.5 Power Consumption Vdd (V) 1.8 3.3 5.0 AT42QT1040 14 Min Typ – 3.5 – 119 -7.5 – – 2 AKS Mode (RAKS) Speed (RFS) Off Off On On Off Off On On Off Off On On ...
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... Ref (4x) K TITLE 20M2, 20-pad 0.85 mm Body, Lead Pitch 0.45 mm, 1.55 x 1.55 mm Exposed Pad, Thermally Enhanced Plastic Very Thin Quad Flat No Lead Package (VQFN) AT42QT1040 C y SIDE VIEW COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM MAX A 0.75 0.80 ...
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... Marking Either of the following two markings may be used: Pin 1 ID Code Revision 1.0 Released AT42QT1040 16 Pin 1 ID 140 R1 Code Revision: 1.0 Released Program Week Code Number 1-52 Where ... then using the underscore A = 27... 140 R1X YZZ Traceability Code (Y = last digit of year; for example 2009 2010, etc ...
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... Revision A – March 2009 Revision B – April 2009 9524B–AT42–04/09 Part Number Description AT42QT1040-MMH 20-pin VQFN RoHS compliant MSL Rating Peak Body Temperature MSL1 AT42QT1040 Specifications o 260 C IPC/JEDEC J-STD-020 History Initial release for chip revision 1.0 Update to pin listing in ...
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... Literature Requests www.atmel.com/literature ® , Atmel logo and combinations thereof, and others are registered trademarks, Adjacent ™ , and others are trademarks of Atmel Corporation or its subsidiaries. Other terms and product names Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 ...