QST104 STMicroelectronics, QST104 Datasheet - Page 14

• Manufacturer Part Number: QST104
• Description: Capacitive touch sensor device 4 keys
• Manufacturer: STMicroelectronics

Device operating modes
4.5.3
Note:
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Option descriptions
Adjacent key suppression (AKS™)
The QST104 features an adjacent key suppression (AKS™) function.
This function is enabled using the AKS option resistor (OPT2) in standard output mode as
described in
of the option resistor configuration.
Table 4.
Low Power mode option
This option resistor (OPT3) selects whether the device is always sensing the keys or if a low
power consumption phase is introduced between bursts as described in
In Low Power mode, a very low consumption (sleep) phase of 100ms is inserted between
two consecutive bursts. This significantly reduces the overall consumption of the device.
Sleep duration is not accurate and can vary substantially depending on V
temperature values.
In Low Power mode, the response time is increased.
Table 5.
Max On-Duration
There are four recalibration timing options (“Max On-Duration”). The recalibration option
resistors (OPT4 and OPT5) control how long it takes for a continuous detection to trigger a
recalibration on a key as described in
key is recalibrated.
Table 6.
OPT4/MOD_0 OPT5/MOD_1
V
V
V
V
OPT2/AKS
SS
SS
DD
DD
OPT3/LP
V
V
V
V
DD
DD
SS
SS
AKS truth table
Low power (LP) mode truth table
Max On-Duration (MOD) truth table
Table
4. In BCD output mode, the AKS function is always enabled, regardless
V
V
V
V
DD
DD
SS
SS
Disabled
Global locking AKS on all available keys
Free running mode
100ms sleep duration
Infinite
60s
20s
10s
Table
6. When such an event occurs, only the “stuck”
Description
Description
Description
Table
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DD
and
5.
QST104