AT42QT2161-MMU Atmel, AT42QT2161-MMU Datasheet - Page 28

• Manufacturer Part Number: AT42QT2161-MMU
• Description: IC TOUCH SENSOR 16KEY QFN M-MOD
• Manufacturer: Atmel
• Type: Capacitiver

Specifications of AT42QT2161-MMU

• Touch Panel Interface: 8, 2-Wire
• Number Of Inputs/keys: 16 Key, Slider
• Resolution (bits): 10 b
• Data Interface: I²C, Serial
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 1.14mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.10
6.11
6.12
28
Address 11: Reset
Address 12: LP Mode
Address 13: Burst Repetition
AT42QT2161
Table 6-10.
Table 6-11.
Table 6-12.
Any nonzero value will trigger the device to reset. After a reset, the device will revert to default
settings.
After receiving a reset command the QT2161 will start not acknowledging I
communications and make CHANGE inactive within 16 ms. The chip will reset after another
~16 ms.
LP mode sets the sleep time between bursts. A higher value causes more sleep time between
acquisitions resulting in lower power consumption, but slower response time.
The values are between 1 – 255, with each incrementing the sleep time by 16 ms steps. For
example, 1 = 16 ms LP, 2 = 32 ms LP, 3 = 48 ms LP, etc.
A value of zero causes the device to enter an ultra-low power mode (SLEEP), where no
measurements are carried out (see
The QT2161 is designed to sleep as much as possible to conserve power.
Note: the longer the LP mode, the longer the response time at first touch. The response time for
the first touch includes the digital filter's settling time (a few measurement cycles) and the DI
process. Above 256 ms LP mode the power consumption does not reduce as much, even with
longer LP mode durations. See
Default value: 1 (16 ms LP)
Burst Repetition (BREP) is a feature that enables the QT2161 to make multiple measurements
and take the average result; this improves the device’s ability to operate in noisy environments.
The number of burst repetitions can be reduced in low noise environments for faster response
time. The BREP value can range between 1 – 63 repetitions. Do not set to 0 because it is not
valid.
Default value:1 (one measurement burst)
Address
Address
Address
11
12
13
Reset
LP Mode
Burst Repetition
b7
b7
b7
0
b6
b6
b6
0
Table 9-1 on page 46
Section 3.17 on page
b5
b5
b5
b4
b4
b4
LP_MODE
RESET
for typical power consumptions.
16).
b3
b3
b3
BREP
b2
b2
b2
b1
b1
b1
2
9614A–AT42–08/10
C-compatible
b0
b0
b0