參數資料
型號: QT310-IS
廠商: Electronic Theatre Controls, Inc.
英文描述: PROGRAMMABLE CAPACITANCE SENSOR IC
中文描述: 可編程電容傳感器IC
文件頁數: 4/20頁
文件大?。?/td> 837K
代理商: QT310-IS
A ‘virtual capacitive ground’ can be created by connecting the
QT310’s own circuit ground to:
(1) A nearby piece of metal or metallized housing;
(2) A floating conductive ground plane;
(3) A fastener to a supporting structure;
(4) A larger electronic device (to which its output might be
connected anyway).
Because the QT310 operates at a relatively low frequency,
about 500kHz, even long inductive wiring back to ground will
usually work fine.
Free-floating ground planes such as metal foils should
maximise exposed surface area in a flat plane if possible. A
square of metal foil will have little effect if it is rolled up or
crumpled into a ball. Virtual ground planes are more effective
and can be made smaller if they are physically bonded to
other surfaces, for example a wall or floor.
1.3.4 F
IELD
S
HAPING
The electrode can be prevented from sensing in undesired
directions with the assistance of metal shielding connected to
circuit ground (Figure 1-5). For example, on flat surfaces, the
field can spread laterally and create a larger touch area than
desired. To stop field spreading, it is only necessary to
surround the touch electrode on all sides with a ring of metal
connected to circuit ground; the ring can be on the same or
opposite side from the electrode. The ring will kill field
spreading from that point outwards.
If one side of the panel to which the electrode is fixed has
moving traffic near it, these objects can cause inadvertent
detections. This is called ‘walk-by’ and is caused by the fact
that the fields radiate from either surface of the electrode
equally well. Again, shielding in the form of a metal sheet or
foil connected to circuit ground will prevent walk-by; putting a
small air gap between the grounded shield and the electrode
will keep the value of Cx lower and is encouraged. In the case
of the QT310, sensitivity can be high enough (depending on
Cx and Cs) that 'walk-by' signals are a concern; if this is a
problem, then some form of rear shielding may be required.
1.4 SENSITIVITY ADJUSTMENTS
There are three variables which influence sensitivity:
1.
2.
3.
Cs (sampling capacitor)
Cx (unknown capacitance)
Signal threshold value
There is also a sensitivity dependence of the whole device on
Vdd. Cs and Cx effects are covered in Section 1.2.1.
The threshold setting can be adjusted independently from 1 to
255 counts of signal swing (Section 2.3).
Note that sensitivity is also a function of other things like
electrode size, shape, and orientation, the composition and
aspect of the object to be sensed, the thickness and
composition of any overlaying panel material, and the degree
of mutual coupling of the sensor circuit and the object (usually
via the local environment, or an actual galvanic connection).
Threshold levels of less than 5 counts in BG mode are not
advised; if this is the case, raise Cs so that the threshold can
also be increased.
1.4.1 I
NCREASING
S
ENSITIVITY
In some cases it may be desirable to greatly increase
sensitivity, for example when using the sensor with very thick
panels having a low dielectric constant, or when sensing low
capacitance objects.
Sensitivity can be increased by using a bigger electrode,
reducing panel thickness, or altering panel composition.
Increasing electrode size can have diminishing returns, as
high values of Cx load will also reduce sensor gain (Figures
5-1 and 5-2). The value of Cs also has a dramatic effect on
sensitivity, and this can be increased in value up to a limit.
Increasing electrode surface area will not substantially
increase sensitivity if its area is already larger than the object
to be detected. The panel or other intervening material can be
made thinner, but again there are diminishing rewards for
L
Q
4
QT310/R1.03 21.09.03
Figure 1-5 Shielding Against Fringe Fields
Figure 1-6 Burst Detail
相關PDF資料
PDF描述
QT320 2 CHANNEL PROGAMMABLE ADVANCED SENSOR IC
QT320-D 2 CHANNEL PROGAMMABLE ADVANCED SENSOR IC
QT320-IS 2 CHANNEL PROGAMMABLE ADVANCED SENSOR IC
QT60040-S IC-SMD-QPROX MATRIX SENSOR
QT60040 4-KEY CHARGE-TRANSFER IC
相關代理商/技術參數
參數描述
QT310-ISG 制造商:Quantum Corp 功能描述:TOUCH SENSOR 1 CHAN SOIC8 310 ((NW))
QT310-ISG SL775 制造商:Atmel Corporation 功能描述:TOUCH PRODUCT - Bulk
QT310-S 功能描述:SENSOR IC TOUCH PROG 1CH 8-SOIC 制造商:microchip technology 系列:QProx?? 包裝:管件 零件狀態(tài):停產 觸摸屏:2 線電容 分辨率(位):16 b 接口:串行 電壓基準:內部 電壓 - 電源:1.8 V ~ 5 V 電流 - 電源:600μA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.209",5.30mm 寬) 供應商器件封裝:8-SO 基本零件編號:QT310 標準包裝:95
QT320 制造商:QUANTUM 制造商全稱:QUANTUM 功能描述:2 CHANNEL PROGAMMABLE ADVANCED SENSOR IC
QT320-D 功能描述:SENSOR IC TOUCH PROG 2CH 8-DIP RoHS:否 類別:集成電路 (IC) >> 數據采集 - 觸摸屏控制器 系列:QProx™ 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數/鍵:- 分辨率(位):- 評估套件:* 數據接口:- 數據速率/采樣率 (SPS,BPS):- 電壓基準:- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:16-TSSOP 包裝:帶卷 (TR)