qt1081 Quantum Research Group, qt1081 Datasheet - Page 7

• Manufacturer Part Number: qt1081
• Description: 8-key Qtouch? Sensor Ic
• Manufacturer: Quantum Research Group

Table 1.6
AKS Resistor Options
Table 1.7
Functions in Simplified Mode
lQ
DETECT OUT
KEY 3
KEY 7
Vunreg
KEY 4
KEY 5
KEY 6
LP IN
*4.7uF
Voltage Reg
+2.8 ~ +5V
Keep these parts
close to the IC
R
R
R
R
SNS3
SNS4
SNS5
R
10K
SNS6
10K
10K
SNS7
10K
*4.7uF
Function
Output Drive, Polarity
SYNC/LP pin
Max on-duration delay
Detect Pin
SMR
C
C
C
C
C
1M
Figure 1.2 Connection Diagram - Simplified Mode
S4
S5
S7
S3
1nF
1nF
S6
1nF
1nF
AKS_0
12
13
15
16
17
21
Vdd
18
19
20
22
Vss
23
24
*100nF
SNS3
SNS3K
SNS4
SNS4K
SNS5
SNS5K
SNS6
SNS7
SNS7K
VSS
SYNC/LP
DETECT
SNS6K
VDD
QT1081
32-QFN
VDD
AKS MODE
3
On, global
Off
/RST
2
Parameter
One-per-key outputs, push-pull, active high
180ms nom LP function; sync not available
60 seconds (nom)
Active high on any detect
7
OUT_7
OUT_6
OUT_5
OUT_4
OUT_3
OUT_2
OUT_1
OUT_0
SNS2K
SNS1K
SNS0K
SNS2
SNS1
SNS0
OSC
SS
* Note: one bypass capacitor to be tightly wired
between Vdd and Vss. Follow manufacturer’s
recommendations for input and output capacitors.
11
10
9
8
7
6
4
1
32
31
30
29
28
27
26
25
Rb1
Rb2
FAST-DETECT
VDD
Keep these parts
1nF
1nF
1nF
Enabled
close to the IC
C
C
C
Off
S2
S1
S0
1M
The required value of spread-spectrum capacitor
will vary according to the lengths of the acquire bursts,
see Section 3.2. A typical value of
R
R
R
AKS_0
10K
SNS1
10K
10K
SNS2
SNS0
Vdd / Vss
C
SS
OUT_7
OUT_6
OUT_5
OUT_4
OUT_3
OUT_2
OUT_1
OUT_0
OUT_0
Recommended Rb1, Rb2 Values
Vdd Range
2.8 ~ 3.59V
QT1081_1R0.04_0307
3.6 ~ 5V
KEY 2
KEY 1
KEY 0
CSS
12K
15K
Rb1
is 100nF.
Rb2
22K
27K
CSS