Electronic Components Datasheet Search
  English  ▼

Delete All


Preview PDF Download HTML

QT100 Datasheet(PDF) 6 Page - Quantum Research Group

Part # QT100
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  QUANTUM [Quantum Research Group]
Direct Link  http://www.qprox.com
Logo QUANTUM - Quantum Research Group

QT100 Datasheet(HTML) 6 Page - Quantum Research Group

Back Button QT100_07 Datasheet HTML 2Page - Quantum Research Group QT100_07 Datasheet HTML 3Page - Quantum Research Group QT100_07 Datasheet HTML 4Page - Quantum Research Group QT100_07 Datasheet HTML 5Page - Quantum Research Group QT100_07 Datasheet HTML 6Page - Quantum Research Group QT100_07 Datasheet HTML 7Page - Quantum Research Group QT100_07 Datasheet HTML 8Page - Quantum Research Group QT100_07 Datasheet HTML 9Page - Quantum Research Group QT100_07 Datasheet HTML 10Page - Quantum Research Group Next Button
Zoom Inzoom in Zoom Outzoom out
 6 / 12 page
background image
2.9.2 HeartBeat™ Output
The QT100 output has a HeartBeat™ ‘health’ indicator
superimposed on it in both LP and SYNC modes. This
operates by taking the output pin into a three-state mode for
15µs once before every QT burst. This output state can be
used to determine that the sensor is operating properly, or it
can be ignored, using one of several simple methods.
The HeartBeat indicator can be sampled by using a pull-up
resistor on the OUT pin, and feeding the resulting
positive-going pulse into a counter, flip flop, one-shot, or other
circuit. The pulses will only be visible when the chip is not
detecting a touch.
If the sensor is wired to a microcontroller as shown in
Figure 2.7, the microcontroller can reconfigure the load
resistor to either VSS or VDD depending on the output state of
the QT100, so that the pulses are evident in either state.
Electromechanical devices like relays will usually ignore the
short Heartbeat pulse. The pulse also has too low a duty cycle
to visibly affect LEDs. It can be filtered completely if desired,
by adding an RC filter to the output, or if interfacing directly
and only to a high-impedance CMOS input, by doing nothing
or at most adding a small noncritical capacitor from OUT to
2.9.3 Output Drive
The OUT pin is active high and can sink or source up to 2mA.
When a large value of Cs (>20nF) is used the OUT current
should be limited to <1mA to prevent gain-shifting side effects,
which happen when the load current creates voltage drops on
the die and bonding wires; these small shifts can materially
influence the signal level to cause detection instability.
3 Circuit Guidelines
3.1 Application Note
Refer to Application Note AN-KD02, downloadable from the
Quantum website for more information on construction and
design methods. Go to http://www.qprox.com, click the
Support tab and then Application Notes.
3.2 Sample Capacitor
Charge sampler capacitor Cs should be a stable type, such as
X7R ceramic or PPS film. The normal Cs range is from 2nF to
50nF depending on the sensitivity required; larger values of
Cs demand higher stability to ensure reliable sensing.
For more consistent sensing from unit to unit, 5 percent
tolerance capacitors are recommended. X7R ceramic types
can be obtained in 5 percent tolerance at little or no extra cost.
3.3 Power Supply, PCB Layout
The power supply can range between 2.0V and 5.0V. At 3V
current drain averages less than 500µA in Fast mode.
If the power supply is shared with another electronic system,
care should be taken to ensure that the supply is free of digital
spikes, sags, and surges which can adversely affect the
QT100. The QT100 will track slow changes in VDD, but it can
be badly affected by rapid voltage fluctuations. It is highly
recommended that a separate voltage regulator be used just
for the QT100 to isolate it from power supply shifts caused by
other components.
If desired, the supply can be regulated using a Low Dropout
(LDO) regulator, although such regulators often have poor
transient line and load stability. See Application Note
AN-KD02 (see Section 3.1) for further information on power
supply considerations.
Parts placement: The chip should be placed to minimize the
SNSK trace length to reduce low frequency pickup, and to
reduce stray Cx which degrades gain. The Cs and Rs
resistors (see Figure 1.1) should be placed as close to the
body of the chip as possible so that the trace between Rs and
the SNSK pin is very short, thereby reducing the antenna-like
ability of this trace to pick up high frequency signals and feed
them directly into the chip. A ground plane can be used under
the chip and the associated discretes, but the trace from the
Rs resistor and the electrode should not run near ground to
reduce loading.
For best EMC performance the circuit should be made entirely
with SMT components.
Electrode trace routing: Keep the electrode trace (and the
electrode itself) away from other signal, power, and ground
traces including over or next to ground planes. Adjacent
switching signals can induce noise onto the sensing signal;
any adjacent trace or ground plane next to, or under, the
electrode trace will cause an increase in Cx load and
desensitize the device.
Important Note: for proper operation a 100nF (0.1µF)
ceramic bypass capacitor must be used directly between
VDD and VSS, to prevent latch-up if there are substantial
VDD transients; for example, during an ESD event. The
bypass capacitor should be placed very close to the
device’s power pins.

Similar Part No. - QT100_07

ManufacturerPart #DatasheetDescription
Quantum Research Group
Quantum Research Group
QT100_0707 QUANTUM-QT100_0707 Datasheet
73Kb / 12P
More results

Similar Description - QT100_07

ManufacturerPart #DatasheetDescription
Quantum Research Group
Quantum Research Group
QT100_0707 QUANTUM-QT100_0707 Datasheet
73Kb / 12P
QT160 QUANTUM-QT160 Datasheet
701Kb / 12P
QT100 QUANTUM-QT100 Datasheet
64Kb / 10P
QT102 QUANTUM-QT102 Datasheet
178Kb / 18P
QT9701B QUANTUM-QT9701B Datasheet
555Kb / 28P
QT60040 QUANTUM-QT60040 Datasheet
295Kb / 10P
QT114 QUANTUM-QT114 Datasheet
308Kb / 12P
QT9701B2 QUANTUM-QT9701B2 Datasheet
706Kb / 30P
QT60320 QUANTUM-QT60320 Datasheet
376Kb / 14P
QT60320C QUANTUM-QT60320C Datasheet
375Kb / 14P
More results

Html Pages

1  2  3  4  5  6  7  8  9  10  11  12 

Datasheet Download

Go To PDF Page

Link URL

Privacy Policy
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com

Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com  |   allmanual.com