|
|
PDF QT60486 Data sheet ( Hoja de datos )
| Número de pieza | QT60486 | |
| Descripción | (QT60326 / QT60486) 32 & 48 KEY QMATRIX ICs | |
| Fabricantes | QUANTUM | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de QT60486 (archivo pdf) en la parte inferior de esta página. Total 30 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
lQ
QT60326, QT60486
32 & 48 KEY QMATRIX™ ICs
z Advanced second generation QMatrix™ controller
z Keys individually adjustable for sensitivity, response
time, and many other critical parameters
z Panel thicknesses to 50mm through any dielectric
z 32 and 48 key versions
z 100% autocal for life - no in-field adjustments
z SPI Slave and UART interfaces
z Sleep mode with wake pin
z Adjacent key suppression feature
z Synchronous noise suppression pin
z Spread-spectrum modulation: high noise immunity
z Mix and match key sizes & shapes in one panel
z Low overhead communications protocol
z FMEA compliant design features
z Negligible external component count
z Extremely low cost per key
z 44-pin Pb-free TQFP package
MOSI
MISO
SCK
/RST
Vdd
Vss
XT2
XT1
RX
TX
WS
144 43 42 41 40 39 38 37 36 35 3343
2 32
3 31
4 QT60326 30
5 QT60486 29
6 28
7
8
TQFP-44
27
26
9 25
10 24
11
12
13
14
15
16
17
18
19
20
23
21 22
Y3B
Y2B
Y1B
Y0B
Vdd
Vss
Vdd
X7
X6
X5
X4
APPLICATIONS -
y Security keypanels
y Industrial keyboards
y Appliance controls
y Outdoor keypads
y ATM machines
y Touch-screens
y Automotive panels
y Machine tools
These digital charge-transfer (“QT”) QMatrix™ ICs are designed to detect human touch on up 48 keys when used with a scanned,
passive X-Y matrix. They will project touch 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 QmBtn program, or from a
host microcontroller. Key setups are stored in an onboard eeprom and do not need to be reloaded with each powerup.
These devices 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. 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 parts can scan matrix touch keys over LCD panels or other displays when used with clear ITO electrodes arranged in a matrix.
They do 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 passive parts, all of which can fit into a 6.5 sq cm footprint (1 sq inch). Control and
data transfer is via either an SPI or UART port.
These devices 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. Unlike older methods, it does not require one IC per key.
TA
-400C to +1050C
-400C to +1050C
AVAILABLE OPTIONS
# Keys
Part Number
32 QT60326-AS-G
48 QT60486-AS-G
LQ
Copyright © 2003-2005 QRG Ltd
QT60486-AS R8.01/0105
1 page  
Figure 2-4 X-Drive Pulse Roll-off and Dwell Time
X drive
Dwell time
Y gate
Lost charge due to
inadequate settling
before end of dwell time
Figure 2-5 Probing X-Drive Waveforms with a Coin
Figure 2-6 Recommended Key Structure
‘T’ should ideally be similar to the complete thickness the fields need to
penetrate to the touch surface. Smaller dimensions will also work but will give
less signal strength. If in doubt, make the pattern coarser.
2.7 Signal Levels
Using Quantum’s QmBtn™ software it is easy to observe the
absolute level of signal received by the sensor on each key.
The signal values should normally be in the range from 250 to
750 counts with properly designed key shapes (see appropriate
Quantum app note on matrix key design). However, long
adjacent runs of X and Y lines can also artificially boost the
signal values, and induce signal saturation: this is to be
avoided. The X-to-Y coupling should come mostly from
intra-key electrode coupling, not from stray X-to-Y trace
coupling.
QmBtn software is available free of charge on Quantum’s web
site.
The signal swing from the smallest finger touch should
preferably exceed 10 counts, with 15 being a reasonable target.
The signal threshold setting (NTHR) should be set to a value
guaranteed to be less than the signal swing caused by the
smallest touch.
Increasing the burst length (BL) parameter will increase the
signal strengths as will increasing the sampling resistor (Rs)
values.
2.8 Matrix Series Resistors
The X and Y matrix scan lines should use series resistors
(referred to as Rx and Ry respectively) for improved EMI
performance.
X drive lines require them in most cases to reduce edge rates
and thus reduce RF emissions. Typical values range from 1K to
20K✡.
Y lines need them to reduce EMC susceptibility problems and in
some extreme cases, ESD. Typical Y values range around
1K✡. Y resistors act to reduce susceptibility problems by
forming a natural low-pass filter with the Cs capacitors.
It is essential that the Rx and Ry resistors and Cs capacitors be
placed very close to the chip. Placing these parts more than a
few millimeters away opens the circuit up for high frequency
interference problems (above 20MHz) as the trace lengths
between the components and the chip start to act as RF
antennae.
The upper limits of Rx and Ry are reached when the signal
level and hence key sensitivity are clearly reduced. The limits of
Rx and Ry will depending on key geometry and stray
capacitance, and thus an oscilloscope is required to determine
optimum values of both.
The upper limit of Rx can vary depending on key geometry and
stray capacitance, and some experimentation and an
oscilloscope are required to determine optimum values.
Dwell time (page 22) affects the duration in which charge
coupled from X to Y can be captured. Increasing the dwell will
increase the signal levels lost to higher values of Rx and Ry, as
shown in Figure 2-4. Too short a dwell time will cause charge to
be 'lost', if there is too much rising edge roll-off. Lengthening
the dwell time will cause this lost charge to be recaptured,
thereby restoring key sensitivity. In these devices, dwell time is
adjustable (see Section 5.11) to one of 3 values.
Dwell time problems can also be solved by either reducing the
stray capacitance on the X line(s) (by a layout change, for
example by reducing X line exposure to nearby ground planes
or traces), or, the Rx resistor needs to be reduced in value (or a
combination of both approaches).
One way to determine X settling time is to monitor the fields
using a patch of metal foil or a small coin over the key (Figure
lQ
5 QT60486-AS R8.01/0105
5 Page 
3 Serial Communications
These devices can use either SPI or UART communications
modes; it cannot use both at the same time. The part defaults to
SPI mode unless it receives a byte over the UART interface. If a
UART byte is received at any time, the UART interface is
enabled and the SPI interface is totally disabled until after the
next device reset.
The host device always initiates communications sequences;
the QT is incapable of chattering data back to the host. This is
intentional for FMEA purposes so that the host always has total
control over the communications with the QT60xx6. In SPI
mode the device is a slave, so that even return data following a
command is controlled by the host. In UART mode, the device
will still only respond back to the host after a command, but the
responses are not controlled by the host.
A command from the host always ends in a response of some
kind from the QT. Some transmission types from the host or the
QT employ a CRC check byte to provide for robust
communications.
A DRDY line is provided that handshakes transmissions.
Generally this is needed by the host from the QT to ensure that
transmissions are not sent when the QT is busy or has not yet
processed a prior command. In UART mode this line is
bi-directional, and the QT can use it to suspend transmissions
back to the host if the host is busy.
Initiating or Resetting Communications: After a reset, or,
should communications be lost due to noise or out-of-sequence
reception, the host should send a 0x0f (return last command)
command repeatedly until the compliment of 0x0f, i.e. 0xf0, is
received back. Then, the host can resume normal run mode
communications from a clean start.
Poll rate: The typical poll rate in normal ‘run’ operation should
be no faster than once per 10ms; even 50ms is more than fast
enough to extract status data using the 0x06 command (report
first key: see page 15) in most situations. Streaming commands
like the 0x0d command (dump setups: see page 15) or
multi-byte response commands like 0x07 or 0x08 can and
should pace at the maximum possible rate.
Run Poll Sequence: In normal run mode the host should limit
traffic with a minimalist control structure (see also Section 4.23).
The host should just send a 0x06 command until something
requires a deeper state inspection. If there is more than one key
in detect, the host should use 0x07 to find which additional keys
are in detect. If there is an error, the host should ascertain the
error type based on commands 0x0b and 0x0c and take
appropriate action. Issuing a 0x07 command all the time is
wasteful of bandwidth, requires more host processor time, and
actually conveys less information (no error flags are sent via a
0x07 command).
3.1 DRDY Pin
DRDY is an open-drain output (in SPI mode) or bidirectional pin
(in UART mode) with an internal 20K ~ 50K pull-up resistor.
Serial communications pacing is controlled by this pin. In either
UART or SPI mode, the host is permitted to send data only
when DRDY is high. In UART mode, the device additionally will
hold up responses to the host if DRDY is being held low by the
host. After a byte is received DRDY will always go low even if
only for a few microseconds; during this period the host should
not send data. Therefore, after each byte transmission the host
should first check that DRDY is high again.
If the host desires to send a byte to the QT it should behave as
follows:
1. If DRDY is low, wait
2. If DRDY is high: send a command to QT
3. Wait 20µs (time S5 in Figure 3-3: DRDY is guaranteed to
go low before this 20µs expires)
4. Wait until DRDY is high (it may already be high again)
5. Send next command or a null byte 0x00 to QT
It takes up to 1ms for DRDY to go high again after a command,
except for a few commands listed in Section 4:
0x01 (Setups load):
0x0E (Get eeprom CRC):
0x16 (Sleep):
<20ms
<20ms
<5ms
Other DRDY specs:
Min time DRDY is low:
Min time DRDY is low after reset:
1µs
1ms
3.2 SPI Communications
SPI mode is selected by default after reset. There is no other
configuration required to make the device operate in SPI mode.
If a UART byte occurs before or even after SPI transmissions
have taken place, the device will switch to UART mode and
remain in that mode until the device is reset.
Figure 3-1 Basic SPI Connections
Host MCU
QT60xx6
P_IN
P_OUT
SCK
MISO
MOSI
DRDY
SS
SCK
MISO
MOSI
Figure 3-2 Filtered SPI Connections
Host MCU
P_IN
P_OUT1
SCK
MISO
MOSI
P_OUT2
Ra
Ca
Ra
Ra
Ra
Ca
Ra
1K
QT60xx6 Circuit
DRDY
SS
X drives
(1 of 8
shown)
Ca SCK
Ca
MISO
Y Lines
MOSI (1 of 6
shown)
Ca
RESET
1nF
Recommended Values of Ra & Ca
SPI Clock Rate
4MHz
400kHz
100kHz
50kHz
Ra
680
1,000
2,200
2,200
Ca
33pF
270pF
470pF
1nF
Xn
Yn
lQ
11 QT60486-AS R8.01/0105
11 Page | ||
| Páginas | Total 30 Páginas | |
| PDF Descargar | [ Datasheet QT60486.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| QT60485 | (QT60325 - QT60645) QMatrix KEYPANEL SENSOR ICS | QUANTUM |
| QT60485B | (QT60325B - QT60645B) QMatrix KEYPANEL SENSOR ICS | QUANTUM |
| QT60486 | (QT60326 / QT60486) 32 & 48 KEY QMATRIX ICs | QUANTUM |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |