`
`’I 6 KEY GMatrixTM KEYPANEL SENSOR IC
`
`GTBCH 61
`
`0 Advanced second generation QMatrix controller
`O 16 touch keys through any dielectric
`0 100% autocal for life - no adjustments required
`O SPI Slave or Master/Slave interface to a host controller
`
`0 Parallel scan interface for electromechanical compatibility
`0 Keys individually adjustable for sensitivity, response time,
`and many other critical parameters
`0 Sleep mode with wake pin
`O Synchronous noise suppression
`0 Mix and match key sizes & shapes in one panel
`0 Adjacent key suppression feature
`0 Panel thicknesses to 5 cm or more
`0 Low overhead communications protocol
`..
`O 44-pin TQFP package
`
`APPLICATIONS -
`
`O O O O
`< D
`
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`
`
`
`
`
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`QT50151
`TQFP—44
`
`. Security keypanels
`0 Industrial keyboards
`
`‘ Appliance controls
`0 Outdoor keypads
`
`- ATM machines
`o Touch-screens
`
`‘ Automotive panels
`0 Machine tools
`
`The OTC-30161 digital charge—transfer (“QT") QMatrixTM IC is designed to detect human touch on up 16 keys when used in
`conjunction with a scanned, passive X—Y matrix. It will project the keys through almost any dielectric, e.g. glass, plastic, stone,
`ceramic, and even wood, up to thicknesses of 5 cm or more. The touch areas are defined as simple 2—part interdigitated
`electrodes of conductive material, like copper or screened silver or carbon deposited on the rear of a control panel. Key sizes,
`shapes and placement are almost entirely arbitrary; sizes and shapes of keys can be mixed within a single panel of keys and can
`vary by a factor of 20:1 in surface area. The sensitivity of each key can be set individually via simple functions over the SPI or
`UART port, for example via Quantum‘s Qthn program, or from a host microcontroller. Key setups are stored in an onboard
`eeprom and do not need to be reloaded with each powerup.
`
`The device is designed specifically for appliances, electronic kiosks, security panels, portable instruments, machine tools, or
`similar products that are subject to environmental influences or even vandalism. It can permit the construction of 100% sealed,
`watertight control panels that are immune to humidity, temperature, dirt accumulation, or the physical deterioration of the panel
`surface from abrasion, chemicals, or abuse. To this end the device contains Quantum—pioneered adaptive auto self—calibration,
`drift compensation, and digital filtering algorithms that make the sensing function robust and survivable.
`
`The part can scan matrix touch keys over LCD panels or other displays when used with clear ITO electrodes arranged in a matrix.
`It does not require 'chip on glass' or other exotic fabrication techniques, thus allowing the OEM to source the matrix from multiple
`vendors. Materials such as such common PCB materials or flex circuits can be used.
`
`External circuitry consists of a resonator and a few capacitors and resistors, all of which can lit into a footprint of less than 6 sq. cm
`(1 sq. in). Control and data transfer is via either a SPl or UART port; a parallel scan port provides backwards compatibility with
`scanned electromechanical keys.
`
`The QT60161 makes use of an important new variant of charge—transfer sensing, transverse charge—transfer, in a matrix format
`that minimizes the number of required scan lines. Unlike some older technologies it does not require one sensing IC per key.
`
`AVAILABLE OPTIONS
`TQFPPartNumber
`QTGO161-S
`QTGO161—AS
`
`ODE to +70”C
`4000 to +105°C
`
`o
`‘4' QSLQANELRJOM
`
`Copyright © 2001 Quantum Research Group Ltd
`Pat Pend. R1.01/02.02
`
`Petitioners Samsung and Sony Ex-1021, 0001
`1193RESP_00003827
`
`Petitioners Samsung and Sony Ex-1021, 0001
`
`
`
`©Quantum Research Group Ltd.
`
`Conte nts
`1 Overview ............................................ 4
`1.1 Field Flows ....................................... 4
`12 Circuit Overview ................................... 4
`13 Communications .................................. 4
`2 Signal Processing .................................... 5
`21 Negative Threshold ................................ 5
`22 Positive Threshold ................................. 5
`2.3 Hysteresis ........................................ 5
`2.4 Drift Compensation ................................ 5
`25 Negative Recalibration Delay
`........................ 6
`2.6 Detection Integrator ............................... 6
`27 Positive Recalibration Delay
`......................... 6
`2.8 Signal and Reference Guardbandlng
`.................. 6
`2.9 Adjacent Key Suppression ........................... 7
`2.10 Full Recalibration ................................. 7
`211 Device Status & Reporting .......................... 7
`3 Circuit Operation ..................................... 7
`3.1 Matrix Scan Sequence
`.............................. 7
`3.2 Signal Path ....................................... 8
`3.3 ‘X‘ Electrode Drives
`................................ 8
`3-51 RF! FromX Lines .................................. 8
`3.3.2 Noise Coupling Into Xlines ,,,,,,,,,,,,,,,,,,,,,,,,,, a
`3.4 “7‘ Gate Drives ..................................... 8
`3-41 RF! From Hines .................................. 8
`3.4.2 Noise Coupling Into Y lines __________________________ 8
`3.5 Burst Length & Sensitivity ........................... 8
`3.6 Burst Acquisition Duration .......................... 9
`3.7 Intra-Burst Spacing
`................................ 9
`3.8 Burst Spacing ..................................... 9
`3.9 Sample Capacitors ................................. 9
`3.10 Water Film Suppression ............................ 9
`3.11 Reset Input ...................................... 9
`3.12 Oscillator ........................................ 9
`3.13 Startup / Calibration Times ......................... 9
`3.14 SleepWWake / Noise Sync Pin iWS)
`..................
`0
`315 LED / Alert Output
`.............................. ’ 1
`3.16 Oscilloscope Sync ............................... ’ 1
`3.17 Power Supply & PCB Layout ....................... ’ 1
`3.18 ESD/ Noise Considerations
`.......................
`1
`4 Communications Interfaces .......................... ’ 2
`4.1 Serial Protocol Overview ..........................
`2
`4.2 SPl Port Specifications ............................ ’2
`4.3 SPl Slave-Only Mode .............................. ’2
`4.4 SP1 Master—Slave Mode ............................
`3
`4.5 UART Interface ..................................
`5
`4.6 Sensor Echo and Data Response .................... ’ 5
`4.7 Parallel Scan Port ................................ ’5
`4.8 Eeprom Corruption ..............................
`6
`5 Commands & Functions ............................. ’ 7
`5.1 Direction Commands .............................
`7
`9
`0X57' 09? Command
`............................ ’ 7
`D 0X70 - Put Command
`............................ ’ 7
`5.2 Scope Commands
`............................... ’8
`5 MB - Specific Kev Scope ..........................
`8
`S Oxfii -AII Keys Scope .............................
`8
`X 0x78 - ROW Keys Scone
`
`........................... ’ 8
`
`0X79 ' Column K9V5 SCOPE“ ......................... 18
`V
`53 Status Commands ............................... 18
`0
`0X30 - Signal for Sinaie KEV
`........................ 18
`1
`0X31 - Delta Signal for Single Key ,,,,,,,,,,,,,,,,,,,,, 18
`2 0x32- Reference Value
`........................... 18
`5
`0x35 - Detection Integrator Counts ___________________ 18
`6
`0X36 - Eeprom Checksum __________________________ 18
`7
`0X37 . General Device Status ........................ 19
`<sp> 0X20 - Signal Levels For Group ____________________ 19
`1
`0X21 - Delta Signals for Group _______________________ 19
`0X22 - Reference Levels for Group .................... 19
`% 0X25 - Detect Integrator Counts for Group _____________ 19
`e
`0X65 ~ Error Code for Selected Key
`,,,,,,,,,,,,,,,,,,, 19
`E
`0X45 - Error Codes for Group
`....................... 20
`k
`0X68 - Reporting of First Touched Key ................. 20
`5.4 Setup Commands
`............................... 21
`‘A 0X01 - Negative Detect Threshold ____________________ 21
`*3 0X02 — Positive Detect Threshold _____________________ 21
`*C 0X03 - Negative Threshold Hysteresis .................. 21
`“D 0X04 - Positive Threshold Hysteresis .................. 21
`”F 0X05 - ELIrSf Length .............................. 21
`”G 0W7 - Burst Spacing ............................. 22
`*H 0X08 - Negative Drift Compensation Rate 5 _____________ 22
`‘1 0X09 - Positive Drift Compensation Rate
`............... 22
`*J OXOA — Negative Detect Integrator Limit
`............... 22
`*K 0X09 - Positive Recalibration Delay
`___________________ 23
`“L OXOC — Negative Recalibration Delay ___________________ 23
`AM OXOD - lntra-Burst Pulse Spacing
`____________________ 23
`“N UXDE - Positive Reference Error Band __________________ 23
`*0 ()qu - Negative Reference Error Band
`________________ 23
`”P 0X10 - Adjacent Key Suppression
`.................... 24
`5.5 Supervisory / System Functions
`.................... 24
`6
`0X35 ' Eeprom ChEC/(SUW- .......................... 24
`L
`0X4C - lock Reference Levels
`....................... 24
`b
`0x62 - Recalibra te Keys ___________________________ 24
`I
`0X6C - Return Last Command Character ________________ 25
`r
`0X72 - Reset DGVICG' .............................. 25
`1/ 0:66 - Return Part Version ......................... 25
`W 0X57 - Return Part Signature _______________________ 25
`Z 0X54 - Elite? sleep ............................... 25
`to 0x11 - Data Rate Selection
`........................ 25
`‘R 0X12 ' OSCiIIOSCODe SW7C .......................... 26
`‘W 0x17- Noise Sync
`.............................. 26
`5.6 Function Summary Table
`......................... 27
`5.7 Timing Limitations
`.............................. 30
`6 Electrical Specifications
`............................ 31
`61 Absolute Maximum Specifications .................. 31
`6.2 Recommended Operating conditions
`............... 31
`6.3 DC Specifications ................................ 31
`6.4 Protocol Timing ................................. 31
`6.5 Maximum Dl‘dv Response Delays .................... 32
`7 Mechanical ........................................ 33
`7.1 Dimensions ..................................... 33
`7.2 Marking ........................................ 33
`8 Index ............................................. 34
`
`
`
`RESEARCH GROUP
`'20 §UKN I UM
`
`ii
`
`www.qprox.com QT60161/R1.01
`
`Petitioners Samsung and Sony EX-1021, 0002
`1193RESP_00003828
`
`Petitioners Samsung and Sony Ex-1021, 0002
`
`
`
`©Quantum Research Group Ltd.
`
`Table 1.1 Device Pin List
`
`Pin
`Name
`Type Description
`Master—Out/ Slave In SPI line. In Master/Slave SPI mode is used for both communication directions.
`1
`Most
`I/D PP
`.
`.
`..
`
`In Slave SPl mode is the data input (in only).
`Master-In / Slave Out SPl line. Not used in Master/Slave SPl mode,
`2
`MISC
`“0 PP
`In Slave mode outputs data to host (out only).
`
`3
`SCK
`l/O PP
`SPI Clock. in Master mode is an output; in Slave mode is an input
`
`4
`RST
`l
`Reset input, active low reset
`
`5
`Vdd
`Pwr
`+5V supply
`
`6
`Vss
`Pwr
`Ground
`
`7
`XTO
`0 PP
`Oscillator drive output. Connect to resonator or crystalply
`
`8
`XTI
`l
`Oscillator drive input. Connect to resonator or crystal, or external clock source.
`
`9
`RX
`l
`UART receive input
`10
`TX
`0 PP
`UART transmit out ut
`
`11
`W8
`l
`Wake from Sleep / Sync to noise source
`
`12
`8MP
`0 PP
`Sample output control
`
`13
`XOOPA
`I/O PP
`X0 Drive matrix scan / Communications option A input
`
`14
`X1OPB
`l/O PP
`X1 Drive matrix scan / Communications option B input
`
`15
`X2
`0 PP
`X2 Drive matrix scan
`
`16
`X3
`0 PP
`X3 Drive matrix scan
`
`17
`Vdd
`Pwr
`+5V supply
`
`18
`Vss
`Pwr
`Ground
`
`19
`X80
`l
`X80 Scan input line
`
`20
`X81
`|
`X81 Scan input line
`
`21
`X82
`l
`X82 Scan input line
`
`22
`X83
`l
`X83 Scan input line
`
`23
`YSO
`0 PP
`Y80 Scan output line
`
`24
`YS1
`0 PP
`YS1 Scan output line
`
`25
`Y82
`0 PP
`Y82 Scan output line
`
`26
`Y83
`O PP
`YS3 Scan output line
`
`27
`AVdd
`Pwr
`+5 supply for analog sections
`
`28
`AGnd
`Pwr
`Analog ground
`
`29
`Aref
`Pwr
`+5 supply for analog sections
`
`30
`CSBB
`l/O PP
`C33 control B
`
`31
`C83A
`I/O PP
`Cs3 control A
`
`32
`C828
`l/O PP
`C82 control B
`
`33
`C82A
`l/O PP
`Cs2 control A
`
`34
`C818
`l/O PP
`051 control B
`
`35
`CS1A
`l/O PP
`Cs1 control A
`
`36
`C808
`l/O PP
`C50 control B
`
`37
`CSUA
`I/D PP
`Cs0 control A
`
`38
`Vdd
`Pwr
`+5 supply
`
`39
`Vss
`Pwr
`Ground
`
`40
`LED
`0 PP
`Active low LED status drive / Activity indicator
`
`41
`DRDY
`0 OD
`Data ready output for Slave SPI mode; active low
`
`42
`Vref
`l
`Vref input for conversion reference
`43
`SO
`0 PP
`Oscilloscope sync output
`
`44
`88
`HO OD
`Slave select for SPl direction control; active low
`
`
`
`
`
`
`
`
`IIO:
`
`l = Input
`0 = Output
`Pwr = Power pin
`l/O = Bidirectional line
`PP = Push Pull output drive
`OD = Open drain output drive
`
`
`
`RESEARCH GROUP
`'20 GUKN I UNI
`
`iii
`
`www.qprox.com QT60161/R1.01
`
`Petitioners Samsung and Sony EX-1021, 0003
`1193RESP_00003829
`
`Petitioners Samsung and Sony Ex-1021, 0003
`
`
`
`©Quantum Research Group Ltd.
`
`1 Overview
`QMatrix devices are digital burst mode charge-transfer (QT)
`sensors designed specifically for matrix geometry touch
`controls; they include 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 in under
`6 square centimeters of PCB area.
`
`Figure 1-1 Field flow between X and Y elements
`
`\
`‘\‘\\\\l I 4::
`\\“I I //’;’-
`
`\\\l|I///// ’.
`
`cmos
`driver
`
`Figure 1-4 Sample Electrode Geometries
`
`PARALLEL LINES
`
`SERPENTlNE
`
`SPIRAL
`
`charge driven by the X electrode is partly received onto the
`corresponding Y electrode which is then processed. The part
`uses 4 ‘X' edge—driven rows and 4 'Y' sense columns to sense
`up to 16 keys.
`
`The charge flows are absorbed by the touch of a human
`finger (Figure 1—1) resulting in a decrease in coupling from X
`to Y. Thus, received signals decrease or go negative with
`respect to the reference level during a touch.
`
`As shown in Figure 1—3, water films cause the coupled fields
`to increase slightly, making them easy to distinguish from
`touch.
`
`The device has a wide dynamic range that allows for a wide
`variety of key sizes and shapes to be mixed together in a
`single touch panel. These features permit new types of
`keypad features such as touch—sliders. back-illuminated keys,
`and complex warped panels.
`
`The devices use an SPI interface running at up to 3MHz rates
`to allow key data to be extracted and to permit individual key
`parameter setup, or, a UART port which can run at rates to
`57.6 Kbaud. The serial interface protocol uses simple
`commands; the command structure is designed to minimize
`the amount of data traffic while maximizing the amount of
`information conveyed.
`
`1.2 Circuit Overview
`A basic circuit diagram is shown in Figure 1—5. The ‘X' drives
`are sequentially pulsed in groupings of bursts. At the
`intersection of each ‘X’ and ‘Y’ line in the matrix itself, where
`a key is desired, should be an interdigitated electrode set
`similar to those shown in Figure 1—4. Consult Quantum for
`application assistance on key design.
`
`The device uses fixed external capacitors to acquire charge
`from the matrix during a burst of charge-transfer cycles; the
`burst length can be varied to permit digitally variable key
`signal gains. The charge is converted to digital using a
`single—slope conversion process.
`
`In addition to normal operating and
`setup functions the device can also
`report back actual signal strengths
`and error codes over the serial
`interfaces.
`
`Qthn software for the PC can be
`used to program the IC as well as
`read back key status and signal
`levels in real time.
`
`A parallel scan port is also provided
`that can be used to directly replace
`membrane type keypads.
`
`QMatrix technology employs
`transverse charge—transfer (‘QT')
`sensing, a new technology that
`senses the changes in an electrical
`charge forced across an electrode
`set.
`
`1.1 Field Flows
`Figure 1—1 shows how charge is
`transferred across an electrode set
`to permeate the overlying panel
`material; this charge flow exhibits a
`high dQ/dt during the edge
`transitions of the X drive pulse. The
`
`Figure 1-2 Field Flows When Touched
`
`,,
`
`‘ \
`I r ’
`overlying panel
`a
`‘\\\|I/’;”//
`/ ’—~
`’x’
`\\\III,,,
`
`“'"I’””:" “1‘
`
`V
`element
`
`pleéem
`’
`
`cmos
`driver
`
`_H_J'l__
`
`Figure 1-3 Fields With a Conductive Film
`
`Water film
`
`
`
`Burst mode operation permits the
`use of a passive matrix, reduces RF
`emissions, and provides excellent
`response times.
`Refer to Section 3 for more details
`on circuit operation.
`
`1.3 Communications
`The device uses two variants of SPl
`communications, Slave—only and
`Master-Slave, a UART interface,
`plus a parallel scan interface. Over
`the serial interfaces are used a
`command and data transfer
`structure designed for high levels of
`flexibility using minimal numbers of
`bytes. For more information see
`Sections 4 and 5.
`
`The parallel scan port permits the
`replacement of electromechanical
`keypads that would be scanned by
`a microcontroller; the scan interface
`mimics an electromechanical
`keyboard’s response.
`
`
`OO
`GANT M
`4' RESEARCH GROUP
`
`www.qprox.com QT60161 /R1.01
`
`Petitioners Samsung and Sony Ex-1021, 0004
`1193RESP_00003830
`
`Petitioners Samsung and Sony Ex-1021, 0004
`
`
`
`©Quantum Research Group Ltd.
`
`Figure 1-5 Circuit Block Diagram
`V
`@ptA CCIOpt?-D
`
`QT60161
`
`X1 Al’nn’an’nh KEYMATRIX
`
`Y0 Y1 Y2 Y3
`1.1.4.1-
`‘7‘7‘7‘7
`
`
`ScanOutput
`
`ScanInput
`
`2 Signal Processing
`The device calibrates and processes signals using a number
`of algorithms specifically designed to provide for high
`survivability in the face of adverse environmental challenges.
`The QT60161 provides a large number of processing options
`which can be user—selected to implement very flexible, robust
`keypanel solutions.
`
`2.1 Negative Threshold
`See also command "A, page 21
`
`The negative threshold value is established relative to a key’s
`signal reference value. The threshold is used to determine
`key touch when crossed by a negative—going signal swing
`after having been filtered by the detection integrator (Section
`2.6). Larger absolute values of threshold desensitize keys
`since the signal must travel farther in order to cross the
`threshold level. Conversely, lower thresholds make keys
`more sensitive.
`
`As Cx and Cs drift, the reference point drift-compensates for
`these changes at a user-settable rate (Section 2.4); the
`threshold level is recomputed whenever the
`reference point moves, and thus it also is drift
`compensated.
`
`The threshold is user-programmed using the setup process
`described in Section 5 on a per-key basis.
`
`2.3 Hysteresis
`See also command "C and "D, page 21
`
`Refer to Figure 1—6. The QT6016’l employs programmable
`hysteresis levels of 12.5%, 25%, or 50% of the delta between
`the reference and threshold levels. There are different
`hysteresis settings for positive and negative thresholds which
`can be set by the user. The percentage refers to the distance
`between the reference level and the threshold at which the
`detection will drop out. A percentage of 12.5% is less
`hysteresis than 25%, and the 12.5% hysteresis point is closer
`to the threshold level than to the reference level.
`
`The hysteresis levels are set for all keys only; it is not
`possible to set the hysteresis differently from key to key on
`either the positive or negative hysteresis levels.
`
`2.4 Drift Compensation
`See also commands "H, "l, page 22
`
`Signal levels can drift because of changes in Cx and Cs over
`time. It is crucial that such drift be compensated, else false
`detections, non— detections, and sensitivity shifts will follow.
`The QT60161 can compensate for drift using two setups, "H
`and "l.
`
`Drift compensation is performed by making the reference
`level track the raw signal at a slow rate, but only while there is
`no detection in effect. The rate of adjustment must be
`performed slowly, otherwise legitimate detections could be
`ignored. The devices drift compensate using a slew—rate
`limited change to the reference level; the threshold and
`hysteresis values are slaved to this reference.
`
`When a finger is sensed, the signal falls since the human
`body acts to absorb charge from the cross—coupling between
`X and Y lines. An isolated, untouched foreign object (a coin,
`or a water film) will cause the signal to rise very slightly due to
`the enhanced coupling thus created. These effects are
`contrary to the way most capacitive sensors operate.
`
`Once a finger is sensed, the drift compensation mechanism
`ceases since the signal is legitimately detecting an object.
`Drift compensation only works when the key signal in
`question has not crossed the negative threshold level
`(Section 2.1).
`
`The drift compensation mechanism can be made asymmetric
`ifdesired; the drift—compensation can be made to occur in
`one direction faster than it does in the other simply by setting
`l‘H and "l to different settings.
`
`Figure 1—6 Detection and Drift Compensation
`
`The threshold is user—programmed on a per—key
`basis using the setup process (Section 5).
`
`2.2 Positive Threshold
`See also command "B, page 21
`
`The positive threshold is used to provide a
`mechanism for recalibration of the reference point
`when a key's signal moves abruptly to the positive.
`These transitions are described more fully in
`Section 2.7.
`
`mmuuw‘nna‘omw - . ,.
`H steresis
`
`/, Reference
`
`
`
`
`OO
`GANT M
`4' RESEARCH GROUP
`
`www.qprox.com QT60161 /R1.01
`
`Petitioners Samsung and Sony EX-1021, 0005
`1193RESP_00003831
`
`Petitioners Samsung and Sony Ex-1021, 0005
`
`
`
`©Quantum Research Group Ltd.
`
`Drift compensation should usually be set to compensate
`faster for increasing signals than for decreasing signals.
`Decreasing signals should not be compensated quickly, since
`an approaching finger could be compensated for partially or
`entirely before even touching the touch pad. However, an
`obstruction over the sense pad, for which the sensor has
`already made full allowance for, could suddenly be removed
`leaving the sensor with an artificially suppressed reference
`level and thus become insensitive to touch. In this case, the
`sensor should compensate for the object's removal by raising
`the reference level quickly.
`
`The drift compensation rate can be set for each key
`individually, and can also be disabled completely if desired on
`a per—key basis.
`
`Drift compensation and the detection time—outs (Section 2.5)
`work together to provide for robust, adaptive sensing. The
`time-outs provide abrupt changes in reference location
`depending on the duration of the signal ‘event'.
`
`2.5 Negative Recalibration Delay
`See also command "L, page 23
`
`If a foreign object contacts a key the key‘s signal may change
`enough in the negative direction, the same as a normal
`touch, to create an unintended detection. When this happens
`it is usually desirable to cause the key to be recalibrated in
`order to restore its function after a time delay of some
`seconds.
`
`The Negative Recal Delay timer monitors this detection
`duration; if a detection event exceeds the timer‘s setting, the
`key will be recalibrated so that it can function thereafter. The
`"L function can be altered on a key by key basis. It can be
`disabled if desired by setting the "L parameter to zero, so that
`it will never recalibrate automatically.
`
`2.6 Detection Integrator
`See also command "J, page 22
`
`To suppress false detections caused by spurious events like
`electrical noise, the QT60xx5 incorporates a 'detection
`integrator' counter that increments with each detection
`sample until a user—defined limit is reached, at which point a
`detection is confirmed. If no detection is sensed on any of the
`samples prior to the final count, the counter is reset
`immediately to zero, forcing the process to restart.
`
`When an active key is released, the counter must count down
`to zero before the key state is set to ‘off'. Setting a key’s
`detection integrator target value to zero disables that key
`although the bursts for that key continue normally.
`
`The detection integrator is extremely effective at reducing
`false detections at the expense of slower reaction times. In
`some applications a slow reaction time is desirable; the
`detection integrator can be used to intentionally slow down
`touch response in order to require the user to touch longer to
`operate the key.
`
`There are 16 possible values for this function.
`
`2.7 Positive Recalibration Delay
`See also command "K, page 23
`
`A recalibration can occur automatically if the signal swings
`more positive than the positive threshold level. This condition
`can occur if there is positive drift but insufficient positive clrift
`compensation, or if the reference moved negative due to a
`recalibration, and thereafter the signal returned to normal.
`
`As an example of the latter, if a foreign object or a finger
`contacts a key for period longer than the Negative Recal
`Delay, the key is recalibrated to a new lower reference level.
`Then, when the condition causing the negative swing ceases
`to exist (eg. the object is removed) the signal can suddenly
`swing back positive to near its normal reference.
`
`It is almost always desirable in these cases to cause the key
`to recalibrate to the new signal level so as to restore normal
`touch operation. The device accomplishes this by simply
`setting Reference = Signal.
`
`The time required to detect this condition before recalibrating
`is governed by the Positive Recalibration Delay command. In
`order for this feature to operate, the signal must rise through
`the positive threshold level (Section 2.2) for the proscribed
`interval determined by Setup "K.
`
`After the Positive Recal Delay interval has expired and the
`fast—recalibration has taken place, the affected key will once
`again function normally. This interval can be set on a per—key
`basis; it can also be disabled by setting "K to zero.
`
`2.8 Signal and Reference Guardbanding
`See also commands "N, "0, page 23; ‘L’, page 24
`
`The QT60161 provides for a method of self-checking that
`allows the host to ascertain whether one or more key signals
`or reference levels are 'out of spec‘. This feature can be used
`to determine if an X or Y line has broken, the matrix panel
`has delaminated from the control panel, or there is a circuit
`fault. There are two kinds of guardbands, but both report
`using the same two error flags.
`
`Signal guardbanding alerts the host via an error flag if the
`raw signal of a key falls below 64 or rises above 65,471. Bits
`2 or 3 of function ‘e‘ will be set for keys whose signals are
`outside of those limits. The error will also appear in a bitfield
`reported via command ‘E'.
`
`Reference guardbanding alerts the host when the reference
`level of a key falls outside of user-defined levels which can be
`much narrower than the signal guardbanding. The reference
`guardband is determined as a percent deviation from the
`'locked' reference level of each individual key. The signal
`reference levels can be stored into internal eeprom via the
`Lock command ‘L' during production; deviations in reference
`levels that fall outside the guardbands centered on these
`locked reference levels are then reported as errors.
`
`The guardband can be set differently for each signal direction
`relative to the stored and locked levels. The possible settings
`are from 0.1% to 25.5% of signal reference in steps of 0.1%
`as set by commands "N (positive swings) and "0 (negative
`swings). A setting of 0 (zero) disables the corresponding
`guardband direction.
`
`Once the L command has recorded all values of signal
`reference into eeprom, and if guardbanding is enabled, the
`part will compare the actual reference level of each key to its
`corresponding guardbands to see if it falls outside of these
`
`
`
`www.qprox.com QT60161 /R1.01
`
`Petitioners Samsung and Sony EX-1021, 0006
`1193RESP_00003832
`
`Petitioners Samsung and Sony Ex-1021, 0006
`
`
`
`©Quantum Research Group Ltd.
`
`limits. If so, either of bits 2 and 3 of command 'e' will be set
`for that key. The error will also appear in a bitfield reported
`via command 'E‘.
`
`2.9 Adjacent Key Suppression
`See also command "P, page 24
`
`The QT60161 incorporates adjacent key suppression that can
`be enabled on a per—key basis. This feature permits the
`suppression of multiple key presses based on relative signal
`strengths. This feature assists in solving the problem of
`surface water which can bridge a key touch to an adjacent
`key, causing multiple key presses. This feature is also useful
`for panels with tightly spaced keys, where a fingertip can
`partially overlap an adjacent key. This feature will act to
`suppress the signals from the unintended key(s).
`
`Adjacent key suppression works for keys across the entire
`panel and is not restricted to physically adjacent keys; the
`device has no knowledge of which keys are physically
`adjacent. When enabled for a key, adjacent key suppression
`causes detections on that key to be suppressed if any other
`key in the panel has a more negative signal deviation from its
`reference, even if the other key does not have adjacent key
`suppression enabled.
`
`This feature does not account for varying key gains (burst
`length) but ignores the actual negative detection threshold
`setting for the key. if keys in a panel have different sizes, it
`may be necessary to reduce the gains of larger keys relative
`to smaller ones to equalize the effects of adjacent key
`suppression. The signal threshold of the larger keys can be
`altered to compensate for this without causing problems with
`key suppression.
`
`Adjacent key suppression works to augment the natural
`moisture suppression capabilities of the device (Section
`3.10), creating a more robust sensing method.
`
`2.10 Full Recalibration
`See also command ‘b’, page 24
`
`The part fully recalibrates one or more keys after the ‘b’
`command has been issued to it, depending on the current
`scope of the ‘b’ command. The device recalibrates all keys on
`powerup, alter a hard reset via the RST pin or on power up,
`or via a reset using the ‘r’ command. Since the circuit
`tolerates a very wide dynamic signal range, it is capable of
`adapting to a wide mix of key sizes and shapes having widely
`varying Cx coupling capacitances.
`
`If a false calibration occurs due to a key touch or foreign
`object on the keys during powerup, the affected key will
`recalibrate again when the object is removed depending on
`the settings of Positive Threshold and Positive Recal Delay
`(Sections 2.2 and 2.7).
`
`Calibration requires 9 full burst cycles to complete, and so the
`time it takes is dependent on the burst spacing parameter
`(Section 3.8 also, "G, page 22.
`
`2.11 Device Status & Reporting
`
`See also commands ‘7’, page 19; ‘e’, page 19; ‘E’, page 20;
`‘k’, page 20, ‘K’, page 20
`
`The device can report on the general device status or specific
`key states including touches and error conditions, depending
`on the command used.
`
`Usually it is most efficient to periodically request the general
`device status using command ‘7" first, as the response to this
`command is a single byte which reports back on behalf of all
`keys. ‘7’ indicates if there are any keys detecting, calibrating,
`or in error.
`
`if command ‘7’ reports a condition requiring further
`investigation, the host device can then use commands ‘e’, ‘E’,
`‘k’ or ‘K’ to provide further details of the event(s) in progress.
`This hierarchical approach provides for a concise information
`flow using minimal data transfers and low host software
`overhead.
`
`3 Circuit Operation
`A QT60161 reference circuit is shown in Figure 2—1.
`
`3.1 Matrix Scan Sequence
`The circuit operates by scanning each key sequentially, key
`by key. Key scanning begins with location X=0 lY=0. X axis
`keys are known as rows while Y axis keys are referred to as
`columns. Keys are scanned sequentially by row, for example
`the sequence YOXO YOX1 YOX2 YOXS Y1XO etc.
`
`Each key is sampled from 1 to 64 times in a burst whose
`length is determined by Setup "F. A burst is completed
`entirely before the next key is sampled; at the end of each
`burst the resulting analog signal is converted to digital using a
`single—slope conversion process. The length of the burst
`directly impacts on the gain of the key; each key can have a
`unique burst length in order to allow tailoring of key sensitivity
`on a key by key basis.
`
`Figure 3-1 QT60161 Circuit Model
`
`
`
`electrode
`
`electrode
`
`
`Yline(1of4)
`
`
`Cs(1of4)
`Stan
`
`
`Single-slope14bitADC
`
`
`Rs (1 m4}
`
`
`
`www.qprox.com QT60161 /R1.01
`
`Petitioners Samsung and Sony Ex-1021, 0007
`1193RESP_00003833
`
`Petitioners Samsung and Sony Ex-1021, 0007
`
`
`
`©Quantum Research Group Ltd.
`
`3.2 Signal Path
`Refer to Figures 1—5, 3—1, and 3—2.
`
`X-Drives. The X drives are push—pull ClVlOS lines which drive
`charge through the matrix keys on the positive and negative
`edges of X. Only the positive edge of X is used for signal
`purposes, however the negative edge must cause the charge
`across the keys to neutralize p