参数资料
| 型号： | QT60168C-ASG |
| 厂商： | Atmel |
| 文件页数： | 23/28页 |
| 文件大小： | 0K |
| 描述： | IC TOUCH SENSOR 16KEY 32TQFP |
| 标准包装： | 250 |
| 系列： | QMatrix™, QProx™ |
| 类型： | 电容性 |
| 输入数/键： | 16 键 |
| 分辨率（位）： | 9，11 b |
| 评估套件： | 可供 |
| 数据接口： | 串行，SPI? |
| 电源电压： | 3 V ~ 5 V |
| 电流 - 电源： | 25mA |
| 工作温度： | -40°C ~ 105°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-TQFP |
| 供应商设备封装： | 32-TQFP（7x7） |
| 包装： | 托盘 |
| 配用： | 427-1087-ND - BOARD EVAL QT60248-AS QMATRIX |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页当前第23页第24页第25页第26页第27页第28页
For example:
NKE = Number of keys enabled = 20
FDIL = Fast detect integrator limit = 5
BS = Burst spacing = 0.5ms
FMEA = FMEA test time = 5ms
NDIL = Norm detect integrator Limit = 2
HPR = Host polling rate = 10ms
The worst case response time is computed as:
Tr = ((((NKE + FDIL) * BS) + FMEA) * NDIL) + HPR
For the above example values:
Tr = ((((20 + 5) * 0.5ms) + 5ms) * 2) + 10ms = 45ms
2.4 Oscillator
The oscillator is internal to the device. There is no facility for
external clocking.
2.5 Sample Capacitors; Saturation
The charge sampler capacitors on the Y pins should be the
values shown. They should be X7R or NP0 ceramics or PPS
film. The value of these capacitors is not critical but 4.7nF is
recommended for most cases.
Cs voltage saturation is shown in Figure 2-1. This nonlinearity
is caused by excessively negative voltage on Cs inducing
conduction in the pin protection diodes. This badly saturated
signal destroys key gain and introduces a strong thermal
coefficient which can cause 'phantom' detection. The cause of
this is usually from the burst length being too long, the Cs value
being too small, or the X-Y coupling being too large. Solutions
include loosening up the interdigitation of key structures,
separating X and Y lines on the PCB more, increasing Cs, and
decreasing the burst length.
Increasing Cs will make the part slower; decreasing burst
length will make it less sensitive. A better PCB layout and a
looser key structure (up to a point) have no negative effects.
Cs voltages should be observed on an oscilloscope with the
matrix layer bonded to the panel material; if the Rs side of any
Cs ramps more negative than -0.25 volts during any burst (not
counting overshoot spikes which are probe artifacts), there is a
potential saturation problem.
Figure 2-2 shows a defective waveform similar to that of 2-1,
but in this case the distortion is caused by excessive stray
capacitance coupling from the Y line to AC ground, for example
from running too near and too far alongside a ground trace,
ground plane, or other traces. The excess coupling causes the
charge-transfer effect to dissipate a significant portion of the
received charge from a key into the stray capacitance. This
phenomenon is more subtle; it can be best detected by
increasing BL to a high count and watching what the waveform
does as it descends towards and below -0.25V. The waveform
will appear deceptively straight, but it will slowly start to flatten
even before the -0.25V level is reached.
A correct waveform is shown in Figure 2-3. Note that the
bottom edge of the bottom trace is substantially straight
(ignoring the downward spikes).
Unlike other QT circuits, the Cs capacitor values on QT60xx8
devices have no effect on conversion gain. However they do
affect conversion time.
Unused Y lines should be left open.
2.6 Sample Resistors
There are 3 sample resistors (Rs) used to perform single-slope
ADC conversion of the acquired charge on each Cs capacitor.
These resistors directly control acquisition gain: larger values of
Rs will proportionately increase signal gain. Values of Rs can
range from 380K ohms to 1M ohms. 470K ohms is a
reasonable value for most purposes.
Unused Y lines do not require an Rs resistor.
2.7 Signal Levels
Quantum’s QmBtn software makes 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 and values of
Rs. 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
website.
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.
lQ
4
QT60248-AS R4.02/0405
Figure 2-1 VCs - Non-Linear During Burst
(Burst too long, or Cs too small, or X-Y capacitance too large)
Figure 2-2 VCs - Poor Gain, Non-Linear During Burst
(Excess capacitance from Y line to Gnd)
Figure 2-3 Vcs - Correct
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相关代理商/技术参数 |
参数描述 |
|---|---|
| QT60168C-ASG-SL683 | 功能描述:接口 - 专用 Integrated Circuit RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
| QT60240 | 制造商:QUANTUM 制造商全称:QUANTUM 功能描述:16 AND 24 KEY QMATRIX TOUCH SENSOR ICs |
| QT60240-ASG | 制造商:Quantum Corp 功能描述:QPROX SENSOR 24 KEYS SMD MLF-32 |
| QT60240-ATG | 功能描述:接口 - 专用 Integrated Circuit RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
| QT60240-ATG SL924 | 制造商:Atmel Corporation 功能描述:INTEGRATED-CIRCUIT 制造商:Atmel 功能描述:INTEGRATED-CIRCUIT |
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