DataSheet8.cn


PDF ( 数据手册 , 数据表 ) QT60485

零件编号 QT60485
描述 (QT60325 - QT60645) QMatrix KEYPANEL SENSOR ICS
制造商 QUANTUM
LOGO QUANTUM LOGO 


1 Page

No Preview Available !

QT60485 数据手册, 描述, 功能
www.DataSheet4U.com
LQ
PRELIMINARY
QT60325, QT60485, QT60645
32, 48, 64 KEY QMatrixKEYPANEL SENSOR ICS
Advanced second generation QMatrix controllers
Up to 32, 48 or 64 touch keys through any dielectric
Panel thicknesses to 5 cm or more
100% autocal for life - no adjustments required
Keys individually adjustable for sensitivity, response time,
and many other critical parameters
Mix and match key sizes & shapes in one panel
Passive matrix - no components at the keys
Moisture suppression capable
AKS™ - Adjacent Key Suppression feature
Synchronous noise suppression
Sleep mode with wake pin
SPI Slave or Master/Slave interface to a host controller
Low overhead communications protocol
44-pin TQFP package
MOSI
MISO
SCLK
RST
Vdd
Vss
XTO
XTI
X0
X1
X2WS
44 43 42 41 40 39 38 37 36 35 34
1 33
2 32
3 31
4 QT60325 30
5 QT60485 29
6 QT60645 28
7 27
8
9
TQFP-44
26
25
10 24
11 23
12 13 14 15 16 17 18 19 20 21 22
CZ2
YS0
YS1
YS2
Aref
AGnd
AVdd
YC7
YC6
YC5
YC4
APPLICATIONS
Security keypanels
Industrial keyboards
Appliance controls
Outdoor keypads
ATM machines
Touch-screens
Automotive panels
Machine tools
The QT60325, QT60485, and QT60645 digital charge-transfer (“QT”) QMatrix™ ICs are designed to detect human touch on up to
32, 48, or 64 keys respectively using 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 port, for example via Quantum’s QmBtn program. Key setups are stored in an onboard eeprom and do not need to be
reloaded with each power-up.
These ICs are designed specifically for appliances, electronic kiosks, security panels, portable instruments, machine tools, or
similar products that are subject to environmental influences or even vandalism. They 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 devices contain Quantum-pioneered adaptive self-calibration, drift
compensation, and digital filtering algorithms that make the sensing function robust and survivable. The devices use short dwell
times and Quantum’s patent-pending AKS™ feature to permit operation in wet environments.
The parts use a passive key matrix, dramatically reducing cost over older technologies that require an ASIC for every key. The
key-matrix can be made of standard flex material (e.g. Silver on PET plastic) or ordinary PCB material to save cost.
External circuitry consists of an opamp, R2R ladder-DAC network, a common PLD, a FET switch, and a small number of resistors
and capacitors which can fit into a footprint of roughly 8 sq. cm (1.5 sq. in). Control and data transfer is via a SPI port which can
be configured in either a Slave or Master/Slave mode.
QT60xx5 ICs make 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 to provide a high economy of scale.
lQ
AVAILABLE OPTIONS
TA
00C to +700C
00C to +700C
00C to +700C
-400C to +1050C
-400C to +1050C
-400C to +1050C
TQFP
QT60325-S
QT60485-S
QT60645-S
QT60325-AS
QT60485-AS
QT60645-AS
Copyright © 2001 Quantum Research Group Ltd
Pat Pend. R1.05/0802







QT60485 pdf, 数据表
© Quantum Research Group Ltd.
being checked be first fully recalibrated in order to allow the
Cz and DAC offset values to alter.
If a key is outside of a limit, either of bits 2 and 3 of command
'e' will be set for that key. The error will also appear as an
error in a bitfield reported with command 'E'.
Individual keys or groups of keys can be recalibrated with a
single command depending on the current command scope.
The time required to recalibrate many keys is not
multiplicative; the cal process for multiple keys runs in
parallel.
There is no mechanism by which keys will automatically
2.11 Boundary Error Reporting
recalibrate if the reference drifts past a guardband boundary. See also commands e, page 23; ^N, page 27
2.9 Adjacent Key Suppression (AKS)
See also command ^P, page 27
QT60xx5 devices incorporate adjacent key suppression
(AKS- patent pending) that can be selected on a per-key
basis. AKS permits the suppression of multiple key presses
based on relative signal strength. This feature assists in
solving the problem of surface moisture 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 might inadvertently activate an adjacent key.
AKS works for keys that are AKS-enabled anywhere in the
matrix and is not restricted to physically adjacent keys; the
device has no knowledge of which keys are actually
physically adjacent. When enabled for a key, adjacent key
suppression causes detections on that key to be suppressed
if any other AKS-enabled key in the panel has a more
negative signal deviation from its reference.
This feature does not account for varying key gains (burst
length) but ignores the actual negative detection threshold
setting for the key. If AKS-enabled 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
AKS. 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 of narrow gated transfer switches
(Section 3.13), creating a more robust sensing method.
2.10 Full Recalibration
See also command b, page 28
The devices fully recalibrate on powerup, after a hard reset, a
soft reset or after a recalibrate bcommand using an
algorithm that seeks out the optimal level of R2R offset and
Cz cancellation on a per-key basis. After powerup or a reset
the matrix is scanned key by key and appropriate calibrations
are set for each in accordance with user-defined setup
information. Since the circuit can tolerate a very wide 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).
Unlike guardband error reporting, boundary error reporting
only works within the active ADC signal window segment in
which the key's signal resides. Complex factoring of Cz and
Offset are not required for these tests, and the tests do not
require that the key be recalibrated to see the error condition.
Drift compensation can cause a key's reference level to move
near to the border of the ADC's 8-bit signal window; this may
make a key inoperable if the reference pegs near zero,
depriving the signal of the ability to move further negative
when a key is touched. Normally the reference level should
be reasonably centered within the ADC's current range, i.e. at
a level of about 128 decimal / 0x80 hex.
The truth logic for reference level drift error reporting is:
e/b2 = Reference > 191
e/b3 = Reference < 64
where e/b2 is command 'e' bit 2, and e/b3 is command 'e' bit
3. If either bit is set, the key should be recalibrated using
command 'b'. Note that guardbanding errors (Section 2.8)
also use these same bits for error reporting, but
guardbanding does not usually affect these bits until after a
recalibration.
Each Reference Boundary error will also appear as an error
in a bitfield reported from command 'E'.
There is no mechanism by which keys can be made to
automatically recalibrate if the reference drifts past a window
boundary.
2.12 Device Status & Reporting
See also commands 7, page 22; e, page 23; E, page 23;
k, page 23, K, page 24
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 7first, as the response to this
command is a single byte which reports back on behalf of all
keys. 7indicates if there are any keys detecting, calibrating,
or in error.
If command 7reports a condition requiring further
investigation, the host device can then use commands e, E,
kor Kto 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.
Full recalibration is distinct from fast-recalibration, wherein
only the Reference level is quickly adjusted. Full recalibration
requires 26 burst cycles to complete whereas fast
recalibration requires only one cycle (Section 2.5). The time
required for recalibration is dependent on the burst spacing
setting ^G (Section 3.8).
Bit 4 of command 7 reports if there is a discrepancy between
the eeprom and the Flash ROM backup of the eeprom in
case of data corruption; it is also set whenever a Setup
parameter has changed but was not yet been copied into
Flash. See Section 4.6. Resetting the device will force the
eeprom changes to be copied to Flash if legitimate, or it will
lQ
8 www.qprox.com QT60xx5 / R1.05







QT60485 equivalent, schematic
© Quantum Research Group Ltd.
3.22 ESD / Noise Considerations
In general the QT60xx5 will be well protected from static
discharge during use by the overlying panel. However, even
with a dielectric panel transients currents can still flow into
scan lines via induction or in extreme cases, dielectric
breakdown. Porous or cracked materials may allow a spark to
tunnel through the panel. In all cases, testing is required to
reveal any potential problems. The devices have diode
protected pins which can absorb and protect the device from
most induced discharges, up to 5mA.
The X lines are not usually at risk during operation, since they
are low-resistance output drives. The YCn lines are not
directly connected to the matrix and so are not at risk.
However the PLD and the QS3251 are connected to the Y
lines and may require additional ESD protection.
Diode clamps can be used on the X and Y matrix lines. The
diodes should be high speed / high current types such as
BAV99 dual diodes, connected from Vdd to Vss with the
diode junction connected to the matrix pin.
Capacitors placed on the X and Y matrix lines can also help
to a limited degree by absorbing ESD transients and lowering
induced voltages. Values up to 100pF can be used without
causing circuit problems.
The circuit can be further protected by inserting series
resistors into the X and/or Y lines to limit peak transient
current. Values up to 500 ohms can be used in most cases,
but if the dwell time is short this resistance can cause a
reduction in signal gain. RC networks as shown in Figures
4-4 and 4-5 can provide enhanced protection against ESD
while also limiting the effects of external fields.
Bypass capacitors and series resistors can be used to
prevent these effects as shown in Figures 4-4 and 4-5.
4 Serial Interface
QT60xx5 devices use an SPI serial interface to a host MCU.
This port uses a protocol described in Section 5.
4.1 Serial Port specifications
QT60xx5's use an SPI synchronous serial interface with the
following specifications at 6MHz oscillator frequency:
Max clock rate, Fck
Data length
Host command space, Tcm
Response delay to host, Tdr1
Drdy delay from response, Tdr2
Multi-byte return spacing, Tdr3
1.5MHz
8 bits
m 50µs
Table 4-1, also, Sec. 7
1µs to 1ms
15µs to 2ms
The host can clock the SPI at any rate up to and including the
maximum clock rate Fck. The maximum clock rate of the part
in Master mode is determined by Setup ^Q.
The part can operate in either master-slave mode or
slave-only mode, and is thus compatible with virtually all
SPI-capable microcontrollers.
The SPI interface should not be used over long distances due
to problems with signal ringing and introduced noise etc.
unless suitably buffered or filtered with RC networks as
shown in Figures 4-4 and 4-5. Slower data rates with longer
RC timeconstants will provide enhanced resistance to noise
and ringing problems.
External field interference can occur in some cases; these
problems are highly dependent on the interfering frequency
and the manner of coupling into the circuit. PCB layout
(Section 3.21) and external wiring should be carefully
designed to reduce the probability of these effects occurring.
Conversion to asynchronous UART format can be
accomplished by using a microcontroller with conversion
firmware. Using such a conversion device the part can
communicate with Quantum's QmBtn PC software. Consult
Quantum for details.
Of particular note is the length of the connection from the
circuit to the key panel. This connection will act as an
antenna that will resonate at various radio frequencies to
cause interference, and thus should be very short. If RFI
pickup is a problem, the connections should be damped
using ferrite beads or low-value (22 - 100 ohm) series
resistors in all lines including any ground and power lines
running in parallel to the panel.
SPI data noise: In some applications the host MCU can be
some distance from the sensor, with the interface coupled via
ribbon cable. The SPI link is particularly vulnerable to noise
injection on these lines; corrupted or false commands can be
induced from transients on the power supply or ground wiring.
Figure 4-1 SPI Connections
4.2 Protocol Overview
The SPI protocol is based entirely on polled data
transmission, that is, the part will not send data to the host of
its own volition but will do so only in response to specific
commands from the host.
Run-time data responses, such as key detection or error
information, requires simple single-byte functions to evoke a
response from the part.
Setup mode interactions mostly use 2-byte functions from the
host to cause the part to alter its behavior; these functions
also cause writes to the internal eeprom.
The concept of 'scope' is used to allow functions to operate
on individual keys or groupings of keys. The scope of
subsequent functions can be altered by short initial scope
instructions.
Slave-Only
Master-Slave
See Section 5 for protocol details.
Host MCU
P_IN
P_OUT
SCK
MISO
MOSI
SS
Vdd
QT60xx5
DRDY
SS
SCK
MISO
MOSI
MS
Host MCU
SS
SCK
MISO
MOSI
QT60xx5
DRDY
SS
SCK
MISO
MOSI
MS
10K
4.3 SPI Slave-Only Mode
Refer to Figures 4-1 and 4-2. Select Slave-only by
floating Pin 37 (MS) or tying high via a m10K resistor. Pin
37 also functions as an oscilloscope sync output (Section
3.20) and should never be tied directly to a supply rail. In
Slave mode the host must always be in Master mode, as
it controls all SPI activity including clocking of the
lQ
16 www.qprox.com QT60xx5 / R1.05










页数 30 页
下载[ QT60485.PDF 数据手册 ]


分享链接

Link :

推荐数据表

零件编号描述制造商
QT60485(QT60325 - QT60645) QMatrix KEYPANEL SENSOR ICSQUANTUM
QUANTUM
QT60485B(QT60325B - QT60645B) QMatrix KEYPANEL SENSOR ICSQUANTUM
QUANTUM
QT60486(QT60326 / QT60486) 32 & 48 KEY QMATRIX ICsQUANTUM
QUANTUM

零件编号描述制造商
STK15C88256-Kbit (32 K x 8) PowerStore nvSRAMCypress Semiconductor
Cypress Semiconductor
NJM4556DUAL HIGH CURRENT OPERATIONAL AMPLIFIERNew Japan Radio
New Japan Radio
EL1118-G5 PIN LONG CREEPAGE SOP PHOTOTRANSISTOR PHOTOCOUPLEREverlight
Everlight


DataSheet8.cn    |   2020   |  联系我们   |   搜索  |  Simemap