QUANTUM QT100_3R0.08_0307

QT100
CHARGE-TRANSFER QTOUCH™ IC
LQ
This datasheet is applicable to all revision 3 chips
The QT100 charge-transfer (‘QT’) touch sensor is a self-contained digital IC capable
of detecting near-proximity or touch. It will project a touch or proximity field through
any dielectric like glass, plastic, stone, ceramic, and even most kinds of wood. It can
also turn small metal-bearing objects into intrinsic sensors, making them responsive
to proximity or touch. This capability, coupled with its ability to self-calibrate, can lead
to entirely new product concepts.
It is designed specifically for human interfaces, like control panels, appliances, toys,
lighting controls, or anywhere a mechanical switch or button may be found.
OUT
1
6
SYNC/MODE
VSS
2
5
VDD
SNSK
3
4
SNS
AT A GLANCE
Number of keys:
One
Technology:
Patented spread-spectrum charge-transfer (direct mode)
Key outline sizes:
6mm x 6mm or larger (panel thickness dependent); widely different sizes and shapes possible
Key spacing:
7mm center to center or more (panel thickness dependent)
Electrode design:
Solid or ring electrode shapes
Layers required:
One
Electrode materials:
Etched copper, silver, carbon, Indium Tin Oxide (ITO), Orgacon† ink
Electrode Substrates:
PCB, FPCB, plastic films, glass
Panel materials:
Plastic, glass, composites, painted surfaces (low particle density metallic paints possible)
Panel thickness:
Up to 50mm glass, 20mm plastic (electrode size dependent)
Key sensitivity:
Settable via capacitor
Interface:
Digital output, active high
Moisture tolerance:
Good
Power:
2V ~ 5V
Package:
6-pin SOT23-6 RoHS compliant
Signal processing:
Self-calibration, auto drift compensation, noise filtering
Applications:
Control panels, consumer appliances, toys, lighting controls, mechanical switch or button
Patents:
QTouch™ (patented Charge-transfer method)
HeartBeat™ (monitors health of device)
†
Orgacon is a registered trademark of Agfa-Gevaert N.V
AVAILABLE OPTIONS
TA
SOT23-6
-40ºC to +85ºC
LQ
QT100-ISG
CCopyright © 2006-2007 QRG Ltd
QT100_3R0.08_0307
Contents
2.9 Output Features
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Basic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Electrode Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.2 Increasing Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.3 Decreasing Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Operation Specifics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Run Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.2 Fast Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.3 Low Power Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.4 SYNC Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 Max On-duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4 Detect Integrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.5 Forced Sensor Recalibration . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.6 Drift Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.7 Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.8 Spread Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
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.................................... 5
........................................ 5
2.9.2 HeartBeat™ Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.9.3 Output Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Circuit Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Application Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Sample Capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3 Power Supply, PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 Absolute Maximum Specifications . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . 7
4.3 AC Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4 Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.5 DC Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.6 Mechanical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.7 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.8 Moisture Sensitivity Level (MSL) . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Datasheet Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Numbering Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.9.1 Output
2
QT100_3R0.08_0307
1 Overview
Figure 1.1 Basic Circuit Configuration
VDD
1.1 Introduction
SENSE
ELECTRODE
5
The QT100 is a digital burst mode charge-transfer (QT)
sensor designed specifically for touch controls; it includes all
hardware and signal processing functions necessary to
provide stable sensing under a wide variety of changing
conditions. Only a single low cost, noncritical capacitor is
required for operation.
VDD
1
OUT
SNSK
Rs
3
Cs
SNS
Figure 1.1 shows a basic circuit using the device.
4
SYNC/MODE 6
VSS
1.2 Basic Operation
Cx
2
The QT100 employs bursts of charge-transfer cycles to
acquire its signal. Burst mode permits power consumption in
the microamp range, dramatically reduces RF emissions,
lowers susceptibility to EMI, and yet permits excellent
response time. Internally the signals are digitally processed to
reject impulse noise, using a 'consensus' filter which requires
four consecutive confirmations of a detection before the output
is activated.
Note: A bypass capacitor should be tightly wired
between Vdd and Vss and kept close to QT100 pin 5.
The value of Cs also has a dramatic effect on sensitivity, and
this can be increased in value with the trade-off of slower
response time and more power. Increasing the electrode's
surface area will not substantially increase touch sensitivity if
its diameter is already much larger in surface area than the
object being detected. Panel material can also be changed to
one having a higher dielectric constant, which will better help
to propagate the field.
The QT switches and charge measurement hardware
functions are all internal to the QT100.
1.3 Electrode Drive
For optimum noise immunity, the electrode should only be
connected to SNSK.
Ground planes around and under the electrode and its SNSK
trace will cause high Cx loading and destroy gain. The
possible signal-to-noise ratio benefits of ground area are more
than negated by the decreased gain from the circuit, and so
ground areas around electrodes are discouraged. Metal areas
near the electrode will reduce the field strength and increase
Cx loading and should be avoided, if possible. Keep ground
away from the electrodes and traces.
In all cases the rule Cs >> Cx must be observed for proper
operation; a typical load capacitance (Cx) ranges from 5-20pF
while Cs is usually about 2-50nF.
Increasing amounts of Cx destroy gain, therefore it is
important to limit the amount of stray capacitance on both
SNS terminals. This can be done, for example, by minimizing
trace lengths and widths and keeping these traces away from
power or ground traces or copper pours.
1.4.3 Decreasing Sensitivity
In some cases the QT100 may be too sensitive. In this case
gain can be easily lowered further by decreasing Cs.
The traces and any components associated with SNS and
SNSK will become touch sensitive and should be treated with
caution to limit the touch area to the desired location.
2 Operation Specifics
A series resistor, Rs, should be placed in line with SNSK to
the electrode to suppress ESD and EMC effects.
2.1 Run Modes
1.4 Sensitivity
2.1.1 Introduction
1.4.1 Introduction
The QT100 has three running modes which depend on the
state of SYNC, pin 6 (high or low).
The sensitivity on the QT100 is a function of things like the
value of Cs, electrode size and capacitance, electrode 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 ground coupling of both
sensor and object.
2.1.2 Fast Mode
The QT100 runs in Fast mode if the SYNC pin is permanently
high. In this mode the QT100 runs at maximum speed at the
expense of increased current consumption. Fast mode is
useful when speed of response is the prime design
requirement. The delay between bursts in Fast mode is
approximately 1ms, as shown in Figure 2.2.
1.4.2 Increasing Sensitivity
In some cases it may be desirable to increase sensitivity; for
example, when using the sensor with very thick panels having
a low dielectric constant. Sensitivity can often be increased by
using a larger electrode or reducing panel thickness.
Increasing electrode size can have diminishing returns, as
high values of Cx will reduce sensor gain.
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2.1.3 Low Power Mode
The QT100 runs in Low Power (LP) mode if the SYNC line is
held low. In this mode it sleeps for approximately 85ms at the
end of each burst, saving power but slowing response. On
detecting a possible key touch, it temporarily switches to Fast
mode until either the key touch is confirmed or found to be
spurious (via the detect integration process). It then returns to
LP mode after the key touch is resolved as shown in
Figure 2.1.
3
QT100_3R0.08_0307
The SYNC pin is sampled at the end of each burst. If the
device is in Fast mode and the SYNC pin is sampled high,
then the device continues to operate in Fast mode
(Figure 2.2). If SYNC is sampled low, then the device
goes to sleep. From then on, it will operate in SYNC mode
(Figure 2.1). Therefore, to guarantee entry into SYNC
mode the low period of the SYNC signal should be longer
than the burst length (Figure 2.3).
Key
touch
Figure 2.1 Low Power Mode (SYNC held low)
~85ms
sleep
SNSK
QT100
fast detect
integrator
sleep
sleep
However, once SYNC mode has been entered, if the
SYNC signal consists of a series of short pulses (>10µs)
then a burst will only occur on the leading edge of each
pulse (Figure 2.4) instead of on each change of SYNC
signal, as normal (Figure 2.3).
SYNC
OUT
In SYNC mode, the device will sleep after each
measurement burst (just as in LP mode) but will be
awakened by a change in the SYNC signal in either
direction, resulting in a new measurement burst. If SYNC
remains unchanged for a period longer than the LP mode
sleep period (about 85ms), the device will resume
operation in either Fast or LP mode depending on the
level of the SYNC pin (Figure 2.3).
Figure 2.2 Fast Mode Bursts (SYNC held high)
SNSK
QT100
There is no DI in SYNC mode (each touch is a detection)
but the Max On-duration will depend on the time between
SYNC pulses; see Sections 2.3 and 2.4. Recalibration
timeout is a fixed number of measurements so will vary
with the SYNC period.
~1ms
SYNC
Figure 2.3 SYNC Mode (triggered by SYNC edges)
2.2 Threshold
SNSK
QT100
sleep
sleep
SYNC
sleep
The internal signal threshold level is fixed at 10 counts of
change with respect to the internal reference level, which
in turn adjusts itself slowly in accordance with the drift
compensation mechanism.
Revert to Fast Mode
slow mode sleep period
SNSK
QT100
sleep
sleep
sleep
The QT100 employs a hysteresis dropout of two counts
of the delta between the reference and threshold levels.
Revert to Slow Mode
SYNC
Figure 2.4 SYNC Mode (Short Pulses)
SNSK
QT100
>10us
>10us
2.3 Max On-duration
If an object or material obstructs the sense pad the signal
may rise enough to create a detection, preventing further
operation. To prevent this, the sensor includes a timer
which monitors detections. If a detection exceeds the
timer setting the sensor performs a full recalibration. This is
known as the Max On-duration feature and is set to ~80s (at
3V). This will vary slightly with Cs and if SYNC mode is used.
As the internal timebase for Max On-duration is determined by
the burst rate, the use of SYNC can cause dramatic changes
in this parameter depending on the SYNC pulse spacing.
slow mode sleep period
>10us
2.4 Detect Integrator
SYNC
It is desirable to suppress detections generated by electrical
noise or from quick brushes with an object. To accomplish
this, the QT100 incorporates a ‘detect integration’ (DI) counter
that increments with each detection until a limit is reached,
after which the output is activated. If no detection is sensed
prior to the final count, the counter is reset immediately to
zero. In the QT100, the required count is four. In LP mode the
device will switch to Fast mode temporarily in order to resolve
the detection more quickly; after a touch is either confirmed or
denied the device will revert back to normal LP mode
operation automatically.
2.1.4 SYNC Mode
It is possible to synchronize the device to an external clock
source by placing an appropriate waveform on the SYNC pin.
SYNC mode can synchronize multiple QT100 devices to each
other to prevent cross-interference, or it can be used to
enhance noise immunity from low frequency sources such as
50Hz or 60Hz mains signals.
The DI can also be viewed as a 'consensus' filter, that
requires four successive detections to create an output.
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4
QT100_3R0.08_0307
2.5 Forced Sensor Recalibration
The QT100 has no recalibration pin; a forced
recalibration is accomplished when the device is
powered up or after the recalibration timeout.
However, supply drain is low so it is a simple
matter to treat the entire IC as a controllable load;
driving the QT100's VDD pin directly from another
logic gate or a microcontroller port will serve as
both power and 'forced recal'. The source
resistance of most CMOS gates and
microcontrollers are low enough to provide direct
power without problem.
2.6 Drift Compensation
Figure 2.5 Drift Compensation
Signal
H ysteresis
Threshold
R eference
Output
Signal drift can occur because of changes in Cx
and Cs over time. It is crucial that drift be
compensated for, otherwise false detections,
nondetections, and sensitivity shifts will follow.
2.7 Response Time
The QT100's response time is highly dependent on run mode
and burst length, which in turn is dependent on Cs and Cx.
With increasing Cs, response time slows, while increasing
levels of Cx reduce response time. The response time will
also be a lot slower in LP or SYNC mode due to a longer time
between burst measurements.
Drift compensation (Figure 2.5). is performed by making the
reference level track the raw signal at a slow rate, but only
while there is no detection in effect. The rate of adjustment
must be performed slowly, otherwise legitimate detections
could be ignored. The QT100 drift compensates using a
slew-rate limited change to the reference level; the threshold
and hysteresis values are slaved to this reference.
2.8 Spread Spectrum
Once an object is sensed, the drift compensation mechanism
ceases since the signal is legitimately high, and therefore
should not cause the reference level to change.
The QT100 modulates its internal oscillator by ±7.5 percent
during the measurement burst. This spreads the generated
noise over a wider band reducing emission levels. This also
reduces susceptibility since there is no longer a single
fundamental burst frequency.
The QT100's drift compensation is 'asymmetric'; the reference
level drift-compensates in one direction faster than it does in
the other. Specifically, it compensates faster for decreasing
signals than for increasing signals. Increasing signals should
not be compensated for quickly, since an approaching finger
could be compensated for partially or entirely before even
approaching the sense electrode. However, an obstruction
over the sense pad, for which the sensor has already made
full allowance, could suddenly be removed leaving the sensor
with an artificially elevated reference level and thus become
insensitive to touch. In this latter case, the sensor will
compensate for the object's removal very quickly, usually in
only a few seconds.
2.9 Output Features
2.9.1 Output
The output of the QT100 is active-high upon detection. The
output will remain active-high for the duration of the detection,
or until the Max On-duration expires, whichever occurs first. If
a Max On-duration timeout occurs first, the sensor performs a
full recalibration and the output becomes inactive (low) until
the next detection.
With large values of Cs and small values of Cx, drift
compensation will appear to operate more slowly than with the
converse. Note that the positive and negative drift
compensation rates are different.
Figure 2.6
Figure 2.7
Getting HeartBeat pulses with a pull-up resistor
Using a micro to obtain HeartBeat pulses in either output state
VDD
HeartBeat™ Pulses
5
Ro
1
VDD
OUT
SNSK
3
1
P ORT_M.x
OU T
SNSK
3
Ro
SNS
SYNC/MODE
VSS
4
Microcontroller
6
SNS
P ORT_M.y
S Y N C /MOD E
4
6
2
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5
QT100_3R0.08_0307
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.
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.
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.
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 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 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.
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.
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
VSS.
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.
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.
For best EMC performance the circuit should be made entirely
with SMT components.
3 Circuit Guidelines
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.
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
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.
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.
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QT100_3R0.08_0307
4 Specifications
4.1 Absolute Maximum Specifications
Operating temp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40ºC to +85ºC
Storage temp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55OC to +125OC
VDD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5 to +5.25V
Max continuous pin current, any control or drive pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±20mA
Short circuit duration to VSS, any pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . infinite
Short circuit duration to VDD, any pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . infinite
Voltage forced onto any pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.6V to (VDD + 0.6) Volts
4.2 Recommended Operating Conditions
VDD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +2.0 to 5.0V
Short-term supply ripple+noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±5mV
Long-term supply stability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±100mV
Cs value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2nF to 50nF
Cx value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 to 20pF
4.3 AC Specifications
VDD = 3.0V, Cs = 10nF, Cx = 5pF, Ta = recommended range, unless otherwise noted
Parameter
Description
TRC
Recalibration time
TPC
TPT
Min
Typ
Max
Units
Notes
250
ms
Cs, Cx dependent
Charge duration
2
µs
±7.5% spread spectrum variation
Transfer duration
2
µs
±7.5% spread spectrum variation
TG1
Time between end of burst and
start of the next (Fast mode)
1
ms
TG2
Time between end of burst and
start of the next (LP mode)
85
ms
Increases with reducing VDD
TBL
Burst length
ms
Cs and Cx dependent
TR
Response time
THB
Heartbeat pulse width
100
15
ms
µs
4.4 Signal Processing
Description
Min
Typ
Max
Units
Threshold differential
10
counts
Hysteresis
2
counts
4
samples
Positive drift compensation rate
Consensus filter length
2,000
ms/level
Negative drift compensation rate
1,000
ms/level
80
secs
Max on-duration
lQ
7
Notes
(At 3V) Will vary in SYNC mode and with
VDD
QT100_3R0.08_0307
4.5 DC Specifications
VDD = 3.0V, Cs = 10nF, Cx = 5pF, Ta = recommended range, unless otherwise noted
Parameter
Description
Min
VDD
Supply voltage
2
IDD
Supply current
5
Iddl
Supply current, LP Mode
VDDS
Supply turn-on slope
VIL
Low input logic level
VHL
High input logic level
VOL
Low output voltage
VOH
High output voltage
IIL
Typ
Units
5.25
V
600
µA
Depending on supply and run mode
µA
2V
3V
5V
V/s
Required for proper start-up
9
15
35
100
0.8
V
2.2
V
0.6
VDD-0.7
Input leakage current
±1
CX
Load capacitance range
AR
Acquisition resolution
Notes
Max
0
9
V
OUT, 4mA sink
V
OUT, 1mA source
µA
100
pF
14
bits
4.6 Mechanical Dimensions
D
e
L
02NN
E
Aa W
Pin 1
ø
M
H
h
Package type: SOT23-6
Millimeters
Max
Notes
Symbol
Min
M
W
Aa
H
h
D
L
E
e
2.8
2.6
1.5
0.9
0.0
0.35
0.35
0.09
3.10
3.0
1.75
1.3
0.15
0.5
0.55
0.2
Ø
0º
10º
lQ
0.95 BSC
8
Min
Inches
Max
0.110
0.102
0.059
0.035
0
0.014
0.014
0.004
0.122
0.118
0.069
0.051
0.006
0.02
0.022
0.008
0º
10º
Notes
0.038 BSC
QT100_3R0.08_0307
4.7 Marking
SOT23-6 Part Number
Marking
QT100-ISG
02NN (where NN is variable)
4.8 Moisture Sensitivity Level (MSL)
MSL Rating
Peak Body Temperature
Specifications
MSL1
260OC
IPC/JEDEC J-STD-020C
lQ
9
QT100_3R0.08_0307
5 Datasheet Control
5.1 Changes
Changes this issue (datasheet rev 08)
Section 2.1.3, 2.1.4, 2.3, 2.7
Section 3.2
Section 4.3, 4.4, 4.7
Section 5 new
5.2 Numbering Convention
Part Number
Datasheet Issue Number
QT100_MXN.nn_mmyy
Chip Revision
(Where M = Major chip revision,
N = minor chip revision,
X = Prereleased Product
[or R = Released Product])
Datasheet Release Date;
(Where mm = Month, yy = Year)
A minor chip revision (N) is defined as a revision change which does not affect product functionality or datasheet.
The value of N is only stated for released parts (R).
lQ
10
QT100_3R0.08_0307
NOTES:
lQ
11
QT100_3R0.08_0307
lQ
Copyright © 2006-2007 QRG Ltd. All rights reserved
Patented and patents pending
Corporate Headquarters
1 Mitchell Point
Ensign Way, Hamble SO31 4RF
Great Britain
Tel: +44 (0)23 8056 5600 Fax: +44 (0)23 8045 3939
www.qprox.com
North America
651 Holiday Drive Bldg. 5 / 300
Pittsburgh, PA 15220 USA
Tel: 412-391-7367 Fax: 412-291-1015
The specifications set out in this document are subject to change without notice. All products sold and services supplied by QRG are subject
to QRG’s Terms and Conditions of sale and services. QRG patents, trademarks and Terms and Conditions can be found online at
http://www.qprox.com/about/legal.php. Numerous further patents are pending, one or more which may apply to this device or the applications
thereof.
QRG products are not suitable for medical (including lifesaving equipment), safety or mission critical applications or other similar purposes.
Except as expressly set out in QRG's Terms and Conditions, no licenses to patents or other intellectual property of QRG (express or implied)
are granted by QRG in connection with the sale of QRG products or provision of services. QRG will not be liable for customer product design
and customers are entirely responsible for their products and applications which incorporate QRG's products.
Developer: Martin Simmons