AT42QT1011 Datasheet by Microchip Technology

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AT42QT1011
AT42QT1011 Data Sheet
Introduction
The AT42QT1011 is a digital burst mode charge-transfer sensor that is capable of detecting near
proximity or touch, making it ideal for implementing touch controls.
The QT1011 is designed specifically for human interfaces like control panels, appliances, toys, lighting
controls, or anywhere a mechanical switch or button may be found. 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 capacitor is required for operation.
Features
Number of Keys:
One – configurable as either a single key or a proximity sensor
• Technology:
Patented spread-spectrum charge-transfer (direct mode)
Key outline sizes:
6 mm × 6 mm or larger (panel thickness dependent); widely different sizes and shapes
possible
Electrode design:
Solid or ring electrode shapes
PCB Layers required:
– One
Electrode materials:
Etched copper, silver, carbon, Indium Tin Oxide (ITO)
Electrode substrates:
PCB, FPCB, plastic films, glass
Panel materials:
Plastic, glass, composites, painted surfaces (low particle density metallic paints possible)
Panel thickness:
Up to 12 mm glass, 6 mm plastic (electrode size and Cs dependent)
Key sensitivity:
Settable via capacitor (Cs)
• Interface:
Digital output, active high
Moisture tolerance:
Increased moisture tolerance based on hardware design and firmware tuning
Operating Voltage:
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 1
1.8 V – 5.5 V; 17 µA at 1.8 V typical
• Package:
6-pin SOT23-6 RoHS compliant
8-pin UDFN/USON RoHS compliant
Signal processing:
Self-calibration, auto drift compensation, noise filtering
Infinite max on-duration
• Applications:
Control panels, consumer appliances, proximity sensor applications, toys, lighting controls,
mechanical switch or button,
• Patents:
– QTouch® technology (patented charge-transfer method)
HeartBeat (monitors health of device)
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 2
Table of Contents
Introduction......................................................................................................................1
Features.......................................................................................................................... 1
1. Pinout and Schematic................................................................................................5
1.1. Pinout Configurations................................................................................................................... 5
1.2. Pin Descriptions........................................................................................................................... 5
1.3. Schematics...................................................................................................................................6
2. Overview of the AT42QT1011....................................................................................8
2.1. Introduction...................................................................................................................................8
2.2. Basic Operation............................................................................................................................8
2.3. Electrode Drive.............................................................................................................................8
2.4. Sensitivity..................................................................................................................................... 8
3. Operation Specifics................................................................................................. 10
3.1. Run Modes................................................................................................................................. 10
3.2. Threshold....................................................................................................................................11
3.3. Max On-duration.........................................................................................................................12
3.4. Detect Integrator.........................................................................................................................12
3.5. Forced Sensor Recalibration......................................................................................................12
3.6. Drift Compensation.....................................................................................................................12
3.7. Response Time.......................................................................................................................... 13
3.8. Spread Spectrum....................................................................................................................... 13
3.9. Output Features......................................................................................................................... 13
4. Circuit Guidelines.................................................................................................... 15
4.1. More Information........................................................................................................................ 15
4.2. Sample Capacitor.......................................................................................................................15
4.3. UDFN/USON Package Restrictions........................................................................................... 15
4.4. Power Supply and PCB Layout.................................................................................................. 15
4.5. Power On................................................................................................................................... 16
5. Specifications.......................................................................................................... 17
5.1. Absolute Maximum Specifications..............................................................................................17
5.2. Recommended Operating Conditions........................................................................................ 17
5.3. AC Specifications....................................................................................................................... 17
5.4. Signal Processing.......................................................................................................................19
5.5. DC Specifications....................................................................................................................... 20
5.6. Mechanical Dimensions............................................................................................................. 21
5.7. Part Marking............................................................................................................................... 23
5.8. Part Number............................................................................................................................... 23
5.9. Moisture Sensitivity Level (MSL)................................................................................................ 24
6. Associated Documents............................................................................................25
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 3
7. Revision History.......................................................................................................26
The Microchip Web Site................................................................................................ 27
Customer Change Notification Service..........................................................................27
Customer Support......................................................................................................... 27
Microchip Devices Code Protection Feature................................................................. 27
Legal Notice...................................................................................................................28
Trademarks................................................................................................................... 28
Quality Management System Certified by DNV.............................................................29
Worldwide Sales and Service........................................................................................30
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 4
Pin1 ID Pin 1 ID
1. Pinout and Schematic
1.1 Pinout Configurations
1.1.1 6-pin SOT23-6
Pin 1 ID
OUT
SNS
VDD
SYNC/
MODE
SNSK
VSS
1 6
5
4
3
2
1.1.2 8-pin UDFN/USON
Pin 1 ID
OUT
SNSK
VSS
SNS
VDD
SYNC/MODE
N/C
N/C
4
3
2
1 8
7
6
5
1.2 Pin Descriptions
1.2.1 6-pin SOT23-6
Table 1-1. Pin Listing
Name Pin Type Comments If Unused, Connect To...
OUT 1 O Output state
VSS 2 P Supply ground
SNSK 3 I/O Sense pin Cs + Key
SNS 4 I/O Sense pin Cs
VDD 5 P Power
SYNC 6 I SYNC and Mode Input Pin is either SYNC/Slow/Fast Mode, depending on logic
level applied (see Section 3.1)
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 5
bemeen Vdd and Vss and kept close to pin 5,
Legend: I = Input only, O = Output only, push-pull, I/O = Input/output,
OD = Open drain output, P = Ground or power
1.2.2 8-pin UDFN/USON
Table 1-2. Pin Listing
Name Pin Type Comments If Unused, Connect To...
SNSK 1 I/O Sense pin Cs + Key
N/C 2 No connection
N/C 3 No connection
VSS 4 P Supply ground
OUT 5 O Output state
SYNC/
MODE
6 I SYNC and Mode Input Pin is either SYNC/Slow/Fast Mode, depending on logic
level applied (see Section 3.1)
VDD 7 P Power
SNS 8 I/O Sense pin Cs
Legend: I = Input only, O = Output only, push-pull, I/O = Input/output,
OD = Open drain output, P = Ground or power
1.3 Schematics
1.3.1 6-pin SOT23-6
Figure 1-1. Basic Circuit Configuration
Cs
OUT
VDD
SNSK
SNS
SYNC/MODE
VSS
2
6
4
3
1
5
VDD
Rs
Cx
SENSE
ELECTRODE
Note: A bypass capacitor should be tightly wired
between Vdd and Vss and kept close to pin 5.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 6
DE— J_ beMeen Vdd and Vss and kept close m pm 5
1.3.2 8-pin UDFN/USON
Figure 1-2. Basic Circuit Configuration
Cs
OUT
VDD
SNSK
SNS
SYNC/MODE
VSS
4
6
8
1
5
7
Vdd
Rs
Cx
SENSE
ELECTRODE
Note: A bypass capacitor should be tightly wired
between Vdd and Vss and kept close to pin 5.
2
3
NC
NC
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 7
2. Overview of the AT42QT1011
2.1 Introduction
The AT42QT1011 is a digital burst mode charge-transfer sensor that is capable of detecting near-
proximity or touch, making it ideal for implementing touch controls.
With the proper electrode and circuit design, the self-contained digital IC will project a touch or proximity
field to several centimeters 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.
The QT1011 is designed specifically for human interfaces like control panels, appliances, toys, lighting
controls, or anywhere a mechanical switch or button may be found. 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 capacitor is required for operation.
2.2 Basic Operation
Figure 1-1 and Figure 1-2 show basic circuits.
The QT1011 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.
The QT switches and charge measurement hardware functions are all internal to the QT1011.
2.3 Electrode Drive
For optimum noise immunity, the electrode should only be connected to SNSK.
In all cases, the rule Cs >> Cx must be observed for proper operation; a typical load capacitance (Cx)
ranges from 5–20 pF while Cs is usually about 2–50 nF.
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.
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.
A series resistor, Rs, should be placed in line with SNSK to the electrode to suppress ESD and EMC
effects.
2.4 Sensitivity
2.4.1 Introduction
The sensitivity on the QT1011 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
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 8
and composition of any overlaying panel material, and the degree of ground coupling of both sensor and
object.
2.4.2 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, or when the device is used as a proximity sensor. Sensitivity
can often be increased by using a larger electrode or reducing panel thickness. Increasing electrode size
can have diminishing returns, since high values of Cx will reduce sensor gain.
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.
In the case of proximity detection, usually the object being detected is on an approaching hand, so a
larger surface area can be effective.
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 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.
2.4.3 Decreasing Sensitivity
In some cases the QT1011 may be too sensitive. In this case gain can be easily lowered further by
decreasing Cs.
2.4.4 Proximity Sensing
By increasing the sensitivity, the QT1011 can be used as a very effective proximity sensor, allowing the
presence of a nearby object (typically a hand) to be detected.
In this scenario, as the object being sensed is typically a hand, very large electrode sizes can be used,
which is extremely effective in increasing the sensitivity of the detector. In this case, the value of Cs will
also need to be increased to ensure improved sensitivity, as mentioned in Section 2.4.2. Note that,
although this affects the responsiveness of the sensor, it is less of an issue in proximity sensing
applications; in such applications it is necessary to detect simply the presence of a large object, rather
than a small, precise touch.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 9
H il WWW WWW HHWIIHI HIWHIHI SYNC Key [ouch JUMILIHMIIF— WW—mm— >WflflmL
3. Operation Specifics
3.1 Run Modes
3.1.1 Introduction
The QT1011 has three running modes which depend on the state of the SYNC pin (high or low).
3.1.2 Fast Mode
The QT1011 runs in Fast mode if the SYNC pin is permanently high. In this mode the QT1011 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 1 ms,
as shown in the following figure.
Figure 3-1. Fast Mode Bursts (SYNC Held High)
SNSK
SYNC
~1 ms
3.1.3 Low Power Mode
The QT1011 runs in Low Power (LP) mode if the SYNC pin is held low. In this mode it sleeps for
approximately 80 ms 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 the following figure.
Figure 3-2. Low Power Mode (SYNC Held Low)
sleep sleep
SYNC
SNSK sleep
fast detect
integrator
OUT
Key
touch
8 0 ms
3.1.4 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 QT1011 devices to each other to prevent cross-
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 10
interference, or it can be used to enhance noise immunity from low frequency sources such as 50Hz or
60Hz mains signals.
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 3-1). If SYNC is sampled low,
then the device goes to sleep. From then on, it will operate in SYNC mode (Figure 3-2). Therefore, to
guarantee entry into SYNC mode, the low period of the SYNC signal should be longer than the burst
length (Figure 3-3).
Figure 3-3. SYNC Mode (Triggered by SYNC Edges)
SYNC
SYNC
SNSK
SNSK
slow mode sleep period
sleep
sleep
sleepsleep
sleepsleep
Revert to Fast Mode
Revert to Slow Mode
slow mode sleep period
However, once SYNC mode has been entered, if the SYNC signal consists of a series of short pulses
(>10 μs), then a burst will only occur on the falling edge of each pulse (Figure 3-4) instead of on each
change of SYNC signal, as normal (Figure 3-3).
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 80 ms), the device
will resume operation in either Fast or LP mode depending on the level of the SYNC pin (Figure 3-3).
There is no Detect Integrator (DI) in SYNC mode (each touch is a detection),, refer toSection 3.4.
Recalibration timeout is a fixed number of measurements so it will vary with the SYNC period.
Figure 3-4. SYNC Mode (Short Pulses)
SNSK
SYNC
>10 sμ>10 sμ>10 sμ
3.2 Threshold
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.
The QT1011 employs a hysteresis dropout of two counts of the delta between the reference and
threshold levels.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 11
3.3 Max On-duration
The max on-duration of this device is infinite; that is, the device will not automatically recalibrate due to a
persistent detection.
3.4 Detect Integrator
It is desirable to suppress detections generated by electrical noise or from quick brushes with an object.
To accomplish this, the QT1011 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 QT1011, 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.
The DI can also be viewed as a “consensus filter” that requires four successive detections to create an
output.
3.5 Forced Sensor Recalibration
The QT1011 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 QT1011's Vdd pin directly from another logic gate or a
microcontroller port will serve as both power and “forced recalibration”. The source resistance of most
CMOS gates and microcontrollers is low enough to provide direct power without problem.
3.6 Drift Compensation
Signal drift can occur because of changes in Cx and Cs over time. It is crucial that drift be compensated
for; otherwise, false detections, non-detections, and sensitivity shifts will follow.
Drift compensation (Figure 3-5) 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 QT1011 drift compensates using a slew-rate limited
change to the reference level; the threshold and hysteresis values are slaved to this reference.
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.
Figure 3-5. Drift Compensation
The QT1011 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
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 12
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.
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.
3.7 Response Time
The QT1011'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.
3.8 Spread Spectrum
The QT1011 modulates its internal oscillator by ±7.5% 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.
3.9 Output Features
3.9.1 Output
The output of the QT1011 is active-high upon detection.
The output will remain active-high for the duration of the detection.
3.9.2 HeartBeat Output
The QT1011 output has a HeartBeat “health” indicator superimposed on it in all modes. This operates by
taking the output pin into a three-state mode for 15 μs, once before every QT burst. This output state can
be used to determine that the sensor is operating properly, using one of several simple methods, or it can
be ignored.
The HeartBeat indicator can be sampled by using a pull-up resistor on the OUT pin (Figure 3-6), 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.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 13
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Figure 3-6. Obtaining HeartBeat Pulses with a Pull-up Resistor (SOT23-6)
OUT
VDD
SNSK
SNS
SYNC/MODE
VSS
2
6
4
3
1
5
VDD
Ro
HeartBeat" Pulse
If the sensor is wired to a microcontroller as shown in Figure 3-7, the microcontroller can reconfigure the
load resistor to either Vss or Vdd depending on the output state of the QT1011, so that the pulses are
evident in either state.
Figure 3-7. Using a Microcontroller to Obtain HeartBeat Pulses in Either Output State (SOT23-6)
OUT SNSK
SNS
SYNC/MODE 6
4
3
1
Ro
Microcontroller
Port_M.x
Port_M.y
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.
3.9.3 Output Drive
The OUT pin is active high and can sink or source up to 2 mA. When a large value of Cs (>20 nF) is
used, the OUT current should be limited to <1 mA 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.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 14
4. Circuit Guidelines
4.1 More Information
Refer to Application Note QTAN0002, "Secrets of a Successful QTouch® Design", and the "Touch
Sensors Design Guide" (both downloadable from http://www.microchip.com), for more information on
construction and design methods.
4.2 Sample Capacitor
Cs is the charge sensing sample capacitor. The required Cs value depends on the thickness of the panel
and its dielectric constant. Thicker panels require larger values of Cs. Typical values are 2 nF to 50 nF
depending on the sensitivity required; larger values of Cs demand higher stability and better dielectric to
ensure reliable sensing.
The Cs capacitor should be a stable type, such as X7R ceramic or PPS film. For more consistent sensing
from unit to unit, 5% tolerance capacitors are recommended. X7R ceramic types can be obtained in 5%
tolerance at little or no extra cost. In applications where high sensitivity (long burst length) is required, the
use of PPS capacitors is recommended.
For battery powered operation, a higher value sample capacitor is recommended (typical value 8.2 nF).
4.3 UDFN/USON Package Restrictions
The central pad on the underside of the UDFN/USON chip is connected to ground. Do not run any tracks
underneath the body of the chip, only ground.
4.4 Power Supply and PCB Layout
See Section 5.2 for the power supply range. At 3V, current drain averages less than 500 μA 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 QT1011. The QT1011 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 QT1011 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 QTAN0002, "Secrets of a
Successful QTouch® Design" for further information.
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 discrete
components, 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.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 15
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.
Note: For proper operation, a 100 nF (0.1 μF) 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 Vss and Vdd pins.
4.5 Power On
On initial power up, the QT1011 requires approximately 100 ms to power on to allow power supplies to
stabilize. During this time the OUT pin state is not valid and should be ignored.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 16
5. Specifications
5.1 Absolute Maximum Specifications
Operating temperature –40°C to +85°C
Storage temperature –55°C to +125°C
Vdd 0 to +6.5 V
Max continuous pin current, any control or drive pin ±20 mA
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) V
CAUTION: Stresses beyond those listed under Absolute Maximum Specifications may cause permanent
damage to the device. This is a stress rating only and functional operation of the device at these or
other conditions beyond those indicated in the operational sections of this specification is not implied.
Exposure to absolute maximum specification conditions for extended periods may affect device
reliability.
5.2 Recommended Operating Conditions
Vdd +1.8 to 5.5 V
Short-term supply ripple + noise ±20 mV
Long-term supply stability ±100 mV
Cs value 2 to 50 nF
Cx value 5 to 50 pF
5.3 AC Specifications
Table 5-1. Vdd = 3.0 V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted
Parameter Description Min Typ Max Units Notes
Trc Recalibration time 200 ms Cs, Cx dependent
Tpc Charge duration 3.05 μs ±7.5% spread spectrum
variation
Tpt Transfer duration 9.0 μs ±7.5% spread spectrum
variation
Tg1 Time between end of burst and
start of the next (Fast mode)
1.2 – ms
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 17
20m: —3.2000ms DStun 1/ 13992; A: Maximum U'I'IIIV HI Frequency ll]. H'J|
Parameter Description Min Typ Max Units Notes
Tg2 Time between end of burst and
start of the next (LP mode)
80 ms Increases with decreasing
Vdd
See Figure 5-1
Tbl Burst length 2.45 ms Vdd, Cs and Cx dependent.
See Section 4.2 for capacitor
selection.
Tr Response time 100 ms
Thb HeartBeat pulse width 15 μs
Figure 5-1. Tg2 Time Between Bursts (LP Mode)
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 18
2m: —3.5600ms DSton 1/ l a 99% 05. QZEHZ ZSMS 500k points R1022010/01/05 12. 2:18
Figure 5-2. Tbl Burst Length
5.4 Signal Processing
Table 5-2. Vdd = 3.0V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted
Description Min Typ Max Units Notes
Threshold differential 10 counts
Hysteresis 2 counts
Consensus filter length 4 samples
Max on-duration Infinite seconds
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 19
5.5 DC Specifications
Table 5-3. Vdd = 3.0V, Cs = 4.7 nF, Cx = 5 pF, Ta = recommended range, unless otherwise noted
Parameter Description Min Typ Max Units Notes
Vdd Supply voltage 1.8 5.5 V
Idd Supply current, Fast
mode
– 203.0
246.0
378.5
542.5
729.0
μA 1.8 V
2.0 V
3.0 V
4.0 V
5.0 V
IddI Supply current, LP mode 16.5
19.5
34.0
51.5
73.5
μA 1.8 V
2.0 V
3.0 V
4.0 V
5.0 V
Vdds Supply turn-on slope 10 V/s Required for proper start-up
Vil Low input logic level 0.2 × Vdd
0.3 × Vdd
V Vdd = 1.8 V – 2.4 V
Vdd = 2.4 V – 5.5 V
Vhl High input logic level 0.7 × Vdd
0.6 × Vdd
V Vdd = 1.8 V – 2.4 V
Vdd = 2.4 V – 5.5 V
Vol Low output voltage 0.5 V OUT, 4 mA sink
Voh High output voltage 2.3 V OUT, 1 mA source
Iil Input leakage current <0.05 1 μA
Cx Load capacitance range 2 50 pF
Ar Acquisition resolution 9 14 bits
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 20
Atmel
5.6 Mechanical Dimensions
5.6.1 6-pin SOT23-6
DRAWING NO. REV. TITLE GPC
6ST1 B
1/25/13
TAQ
Package Drawing Contact:
packagedrawings@atmel.com
Notes: 1. This package is compliant with JEDEC specification
MO-178 Variation AB.
2. Dimension D does not include mold Flash, protrusions or
gate burrs. Mold Flash, protrustion or gate burrs shall not
exceed 0.25 mm per end.
3. Dimension b does not include dambar protrusion.
Allowable dambar protrusion shall not cause the lead width
to exceed the maximum b dimension by more than 0.08 mm
4. Die is facing down after trim/form.
MAX NOTE
SYMBOL MIN NOM
COMMON DIMENSIONS
(Unit of Measure = mm)
A 1.45
A1 0 0.15
A2 0.90 1.30
D 2.80 2.90 3.00 2
E 2.60 2.80 3.00
E1 1.50 1.60 1.75
L 0.30 0.45 0.55
e 0.95 BSC
b 0.30 0.50 3
c 0.09 0.20
q
Side View
E E1
D
e
A2 A
A1 C
C
0.10
0.25
L
O
A2 A
A1 C
C
0.10
A
A
SEE VIEW B
C
SEATING PLANE
SEATING PLANE
SEATING PLANE
c
b
Pin #1 ID
1
6
23
54
Top View
View B
View A-A
6ST1, 6-lead, 2.90 x 1.60 mm Plastic Small Outline
Package (SOT23)
Note:  For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 21
9 § ! j Side view AL Bottom View 5‘ L7- U U U U \ fl 7 fl WT AtmeL
5.6.2 8-pin UDFN/USON
DRAWING NO. REV. TITLE GPC
8MA4 B
YAG
Package Drawing Contact:
packagedrawings@atmel.com
01/25/13
8MA4, 8-pad, 2.0x2.0x0.6 mm Body, 0.5 mm pitch,
0.9x1.5 mm Exposed ePad, Ultra-Thin Dual Flat
No Lead Package (UDFN/USON)
f
d
COMMON DIMENSIONS
(Unit of Measure = mm)
SYMBOL MIN NOM MAX NOTE
A - - 0.60
A10.00 - 0.05
b 0.20 - 0.30
D 1.95 2.00 2.05
D2 1.40 1.50 1.60
E 1.95 2.00 2.05
E2 0.80 0.90 1.00
e 0.50 BSC
L 0.20 0.30 0.40
k 0.20 - -
1. All dimensions are in mm. Angles in degrees.
2. Coplanarity applies to the exposed pad as well as the terminals.
Coplanarity shall not exceed 0.05 mm.
3. Warpage shall not exceed 0.05 mm.
4. Refer to JEDEC MO-236/MO-252.
NOTES:
1
4
8
5
b
E2
D2
C0.2
e
D
14
PIN 1 ID
E
5
A1
A
C
C
0.05
0.05
8X
C
2 3
678
L
k
Top view Bottom view
Side view
Side view
A
A1
Note:  For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 22
l—If—Il—I p 7.01 + 11 |_l I_l |_l \101 1 / \HE§\ N. Y k\ {Vanab‘e ‘exn \ri
5.7 Part Marking
5.7.1 AT42QT1011– 6-pin SOT23-6
1011
Pin 1 ID
Abbreviated
Part Number:
AT42QT
1011
Note:  Samples of the AT42QT1011 may also be marked T10E.
5.7.2 AT42QT1011 – 8-pin UDFN/USON
Pin 1 ID
1011
Abbreviated
Part Number:
AT42QT
1011
HEC
YZZ
Pin 1
Class code
(H = Industrial,
green NiPdAu)
Die Revision
(Example: “E” shown)
Assembly Location
Code
(Example: “C” shown)
Lot Number Trace
code (Variable text)
Last Digit of Year
(Variable text)
Note:  Samples of the AT42QT1011 may also be marked T10
5.8 Part Number
Part Number Description
AT42QT1011(1) 6-pin SOT23 RoHS compliant IC
AT42QT1011-TSHR 6-pin SOT23 RoHS compliant IC
AT42QT1011-MAH 8-pin UDFN/USON RoHS compliant IC
Notes: 1. Marking details:
Top mark 1st line: ddddTY
Top mark 2nd line: wwxxx
dddd= device, special code
T= Type
Y= Year last digit
ww= calendar workweek
xxx = trace code
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 23
5.9 Moisture Sensitivity Level (MSL)
MSL Rating Peak Body Temperature Specifications
MSL1 260oC IPC/JEDEC J-STD-020
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 24
6. Associated Documents
For additional information, refer to the following document (downloadable from the Touch Technology
area of the Microchip website, www.microchip.com):
Touch Sensors Design Guide
QTAN0002 – Secrets of a Successful QTouch® Design
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 25
7. Revision History
Revision No. History
Revision A – May 2009 Initial release
Revision B – August 2009 Update for chip revision 2.2
Revision C – August 2009 Minor update for clarity
Revision D – January 2010 Power specifications updated for revision 2.4.1
Revision E – January 2010 Part markings updated
Revision F – February 2010 MSL specification revised
Other minor updates
Revision G – March 2010 Update for chip revision 2.6
Revision H – May 2010 UDFN/USON package added
Revision I – May 2013 Applied new template
DS40001947A – August 2017 Part marking clarification added. Replaces Atmel document 9542I.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 26
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Microchip is willing to work with the customer who is concerned about the integrity of their code.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 27
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their
code. Code protection does not mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the
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All other trademarks mentioned herein are property of their respective companies.
© 2017, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 28
ISBN: 978-1-5224-2070-5
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DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and
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systems is ISO 9001:2000 certified.
AT42QT1011
© 2017 Microchip Technology Inc. Datasheet DS40001947A-page 29
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