參數(shù)資料
型號: QT160
廠商: Electronic Theatre Controls, Inc.
英文描述: 6 KEY CHARGE TRANSFER QTOUCH SENSOR IC
中文描述: 6鍵電荷轉(zhuǎn)移一款Qtouch傳感器IC
文件頁數(shù): 3/12頁
文件大?。?/td> 707K
代理商: QT160
do not propagate fields laterally very well, and will have poor
sensitivity in the middle. Experimentation is required.
Since the channels acquire their signals in time-sequence,
any of the 6 electrodes can be placed in direct proximity to
each other if desired without cross-interference.
A good example of backlighting can be found in the E160
eval board for the QT160.
1.3.3 K
IRCHOFF
S
C
URRENT
L
AW
Like all capacitance sensors, these parts rely on Kirchoff
s
Current Law (Figure 1-5) to detect the change in capacitance
of the electrode. This law as applied to capacitive sensing
requires that the sensor
s field current must complete a loop,
returning back to its source in order for capacitance to be
sensed. Although most designers relate to Kirchoff
s law with
regard to hardwired circuits, it applies equally to capacitive
field flows. By implication it requires that the signal ground
and the target object must both be coupled together in some
manner for a capacitive sensor to operate properly. Note that
there is no need to provide actual hardwired ground
connections; capacitive coupling to ground (Cx1) is always
sufficient, even if the coupling might seem very tenuous. For
example, powering the sensor via an isolated transformer
will provide ample ground coupling, since there is
capacitance between the windings and/or the transformer
core, and from the power wiring itself directly to 'local earth'.
Even when battery powered, just the physical size of the
PCB and the object into which the electronics is embedded
will generally be enough to couple a few
picofarads back to local earth.
Electrodes connected to the IC
themselves act as coupling plates back
to local ground, since when one
channel is sensing the other channels
are clamped to circuit ground.
1.3.4 V
IRTUAL
C
APACITIVE
G
ROUNDS
When detecting human contact (e.g. a
fingertip), grounding of the person is
never required. The human body
naturally has several hundred
picofarads of
free space
capacitance
to the local environment (Cx3 in Figure
1-5), which is more than two orders of
magnitude greater than that required to
create a return path to the IC via earth.
The PCB however can be physically
quite small, so there may be little
free
space
coupling (Cx1 in Figure 1-5)
between it and the environment to
complete the return path. If the circuit ground cannot be
earth grounded by wire, for example via the supply
connections, then a
virtual capacitive ground
may be
required to increase return coupling.
A
virtual capacitive ground
can be created by connecting
the IC's own circuit ground to:
(1) A nearby piece of metal or metallized housing;
(2) A floating conductive ground plane;
(3) A nail driven into a wall;
(4) A larger electronic device (to which its output might be
connected anyway).
Free-floating ground planes such as metal foils should
maximize 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.
1.3.5 F
IELD
S
HAPING
The electrode can be prevented from sensing in undesired
directions with the assistance of metal shielding connected
l
Q
3
QT160/161 1.06/1102
Figure 1-2 Internal Switching & Timing
C
s
C
x
SNS2
SNS1
ELECTRODE
S
S
Charge
Amp
B
Result
Done
Start
Figure 1-3 Mesh Key Geometry
Figure 1-4 Open Electrode for Back-Illumination
相關(guān)PDF資料
PDF描述
QT161 6 KEY CHARGE TRANSFER QTOUCH SENSOR IC
QT301 CAPACITANCE TO ANALOG CONVERTER
QT310 PROGRAMMABLE CAPACITANCE SENSOR IC
QT310-D PROGRAMMABLE CAPACITANCE SENSOR IC
QT310-IS PROGRAMMABLE CAPACITANCE SENSOR IC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
QT1608RL080 制造商:MAGIC-TECH 功能描述:
QT160-AS 功能描述:SENSOR IC 6CH 5V 5MA SGL 28-SSOP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:QProx™, QTouch™ 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率(位):- 評估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)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(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)
QT160-ASG 功能描述:IC SENSOR 6CH 5V 5MA SGL 28SSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:QProx™, QTouch™ 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率(位):- 評估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)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(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)
QT160-D 功能描述:SENSOR IC 6-CH 5V 5MA SGL 28-DIP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:QProx™, QTouch™ 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率(位):- 評估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)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(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)
QT160-DG 功能描述:IC SENSOR 6CH 5V 5MA SGL 28DIP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:QProx™, QTouch™ 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率(位):- 評估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)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(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)