QT111 QProxTM 8-pin Sensor

See QT110 datasheet for primary information. This sheet only lists differences with the QT110.

Description

The QT111 is a touch sensor IC having recalibration timeouts ("max on-duration") of 5 minutes and infinity.
This allows the device to be used in situations where recalibration timeouts are not desired, for example in
certain consumer, machine tool and process control applications where continuous touch over long periods is
desired, like hand-on-joystick sensors, dead-man switches, etc. Although the primary application of the device
is still as a `touch sensor', longer timeouts also aknowledge alternate uses for the QT110 family, for example in
process controls.

Differences with QT110

The QT111 sensor is exactly the same in all respects to the QT110 with the following exceptions shown in bold
(refer to Table 2-1 in the QT110 datasheet):

300s

Vdd

Gnd

Pulse

300s

Gnd

Toggle

infinite

Gnd

Vdd

DC Out

300s

Vdd

DC Out

Max On-

Duration

Tie

Pin 4 to:

Tie

Pin 3 to:

Table 2-1 Output Mode Strap Options

All other operating modes, specifications, and wiring should be read from the QT110 data sheet.

Cautionary Notes
Care should be taken in infinite timeout mode that the Cs and Cx capacitances and the Vcc supply
do not drift substantially over the course of a detection; if any of these parameters change
sufficiently during the course of an active detection (remember: drift compensation is never
performed during a detection event) the sensor can either `stick on' after the detected object is
removed, or, the QT110's apparent sensitivity will be substantially reduced for a period of time until
drift compensation can recover the proper reference level. If possible, uses the lowest gain setting
when using with long timeouts.

If the sensor `sticks on' after the detected object or substance is removed from the sense element, the only way
to clear the sensor may be to remove power momentarily in order to induce a full recalibration.

Package Marking
DIP Package: DIP devices are marked 'QT111'
SO8 Package: Marked 'QT1' and also laserscribed '1'

3 August 1999

QT111 QProxTM 8-pin Sensor

QT112 QProxTM 8-pin Sensor

See QT110 datasheet for primary information. This sheet only lists differences with the QT110.

Description

The QT112 is a variant of the QT110 having a faster response time of 49ms worst case, and 25ms typical. It is
designed for those touch sensing applications where faster speed is paramount, for example in games and toys
where rapid reaction time is critical, or in machine tool controls where speed is important. It trades off power
consumption for speed. Also, note that the device has a consensus filter count 2 instead of 4, and does not
have an acoustic driver for a piezo 'beeper'.

Differences with the QT110

The QT112 sensor is exactly the same in all respects to the QT110 with the following exceptions (refer to
Tables 4.3, 4.4, and 4.5 in the QT110 datasheet):

4.3 AC SPECIFICATIONS

Vdd = 3.0, Ta = recommended operating range

Response time

Burst spacing interval

Notes

Units

Max

Typ

Min

Description

Parameter

4.4 SIGNAL PROCESSING

ms/level

Negative drift compensation rate

ms/level

1,250

Positive drift compensation rate

samples

Consensus filter length

Notes

Units

Max

Typ

Min

Description

4.5 DC SPECIFICATIONS

Vdd = 3.0V, Cs = 10nF, Cx = 5pF, Ta = recommended range, unless otherwise noted

�A

Supply current

Notes

Units

Max

Typ

Min

Description

Parameter

Piezo Driver Note:

The piezo acoustic driver has been removed, as the duration required to operate the

beeper would interfere with the sensing interval and slow down the device.

All other operating modes, specifications, and wiring should be taken from the QT110 data sheet.

Package Marking
DIP Package: DIP devices are marked 'QT112'
SO8 Package: Marked 'QT1' and also laserscribed '2'

3 August 1999

QT112 QProxTM 8-pin Sensor

QT113 QProxTM 8-pin Sensor

See QT110 datasheet for primary information. This sheet only lists differences with the QT110.

Description

The QT113 is a variant of the QT110 having variable sensitivity and faster response time in most cases. Unlike
the QT110, it has a variable threshold which can be modified by simply altering the value of the sample
capacitor Cs, which acts to modify gain. In addition, it also includes an 'infinite' max on-duration timeout, so that
it is possible to prevent a recalibration during prolonged detections.

The QT113 is designed for contact sensing applications where faster speed and high sensitivity are paramount,
for example when sensing through thick panels or windows in machine tool applications or certain types of
security monitoring. The QT113 trades off power consumption for speed and sensing range. Also, note that the
device has a consensus filter count of 3 instead of 4, and does not have the drive capability for a piezo 'beeper'.

Differences with the QT110

The QT113 IC is exactly the same in all respects to the QT110 with the following exceptions (refer to Tables
4.2, 4.3, 4.4, and 4.5 in the QT110 datasheet).

4.2 RECOMMENDED OPERATING CONDITIONS

Cx Load Capacitance

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 100pF

Cs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10nF to 500nF

4.3 AC SPECIFICATIONS

VDD = 3.0, TA = RECOMMENDED OPERATING RANGE

Note 1

300

Response time

Cs = 10nf to 500nf, Cx = 0

0.5

Burst length

Cs = 10nf to 500nf, Cx = 0

2.1

Burst spacing interval

Notes

Units

Max

Typ

Min

Description

Parameter

Note 1: Lengthens with increasing Cs but decreases with increasing Cx; see Chart 3.

4.4 SIGNAL PROCESSING

ms/level

100

Negative drift compensation rate

ms/level

1,000

Positive drift compensation rate

samples

Consensus filter length

w.r.t. threshold cts.

Hysteresis

Note 1

counts

Threshold differential, fixed

Note 1

Threshold differential, low gain

Note 1

Threshold differential, medium gain

Note 1

Threshold differential, high gain

Notes

Units

Max

Typ

Min

Description

Note 1: All percentage thresholds have been eliminated and replaced with fixed thresholds (high, low gains) w.r.t. the reference level

4.5 DC SPECIFICATIONS

VDD = 3.0V, CS = 10NF, CX = 10PF, TA = RECOMMENDED RANGE

Typical, see figs 1, 2; Note 1, 2

1,000

Sensitivity range

Note 1

Sensitivity - low gain

S[3]

Note 1

Sensitivity - medium gain

S[2]

Note 1

Sensitivity - high gain

S[1]

Cs = 10nF to 100nF

�A

700

Supply current

Notes

Units

Max

Typ

Min

Description

Parameter

Note 1: All percentage thresholds have been eliminated and replaced with a fixed threshold w.r.t. reference level
Note 2: Sensitivity depends on value of Cx and Cs. Refer to Charts 1, 2.

3 August 1999

QT115 QProxTM 8-pin Sensor

Piezo Driver Note

The piezo acoustic driver has been removed, as the duration required to operate the beeper would interfere with
the sensing interval and slow down the device.

Sensitivity Adjustment

The gain pin adjustment is via fixed thresholds slaved to the reference level. Likewise, gain strapping is
different from the QT110: instead of connecting the Gain pin to SNS1 or SNS2, Gain must be connected to
either Vdd (+) or Gnd as shown in Table 1-1 below. The E110 board does not directly support this and a wire
should be run from the centerpost of the Gain jumper strip to either switched-Vdd or Gnd, as desired.

Vdd

High (6 counts)

Gnd

Low (12 counts)

Tie Pin 5 to:

Gain

Table 1-1 Gain Setting Strap Options

The sensitivity of the circuit is governed also by the relative sizes of Cs and Cx. A detection is made if the
signal rises by 6 or 12 counts from the reference level depending on gain pin strapping; this amount, unlike the
QT110, is not ratiometric to the signal level and therefore the sensitivity can be altered by simply changing Cs
(and by changing gain strapping). To provide a consistent level of sensitivity, only stable types of capacitors are
recommended for Cs, such as NPO, C0G, PPS film, and certain types of polycarbonate when used over normal
room temperature ranges.

Larger values of Cs will make the sensor more sensitive, while larger amounts of Cx will desensitize it (see
Charts 1, 2). Minimizing stray Cx is crucial if high levels of sensitivity are desired. By using values of Cs around
0.47uF (470nF), proximity distances of several centimeters can easily be obtained from small electrodes.

NOTE: It is extremely important to maintain stable levels of Vdd, as the supply is used as a
reference. Minor fluctuations in Vdd WILL cause false triggers or rapid swings in gain. DO NOT use
bench power supplies or supply circuits shared with other digital functions. Ordinary 78L05 class
regulators are fine in almost all cases. The QT113 is an extremely sensitive device. Do not take

power supply issues lightly.

Output Mode and Timing Changes

The QT113 has different output mode strap options from the QT110 as shown:

infinite

Vdd

Gnd

DC Out

10s

Gnd

Toggle

60s

Gnd

Vdd

DC Out

10s

Vdd

DC Out

Max On-

Duration

Tie

Pin 4 to:

Tie

Pin 3 to:

Table 2-1 Output Mode Strap Options

The only change is that 'Pulse Mode' has been replaced by a DC Out mode having no recalibration timeout
(max on-duration set to infinite).

All other operating modes, specifications, and wiring should be taken from the QT110 data sheet.

Calibration and Drift Compensation

Calibration and drift compensation operate in the same manner as in the QT110. 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 August 1999

QT115 QProxTM 8-pin Sensor

Электронный компонент: QT111-IS