QT1081 Datasheet, PDF (6/20 Pages) Quantum Research Group – 8-KEY QTOUCH SENSOR IC

Vunreg
*4.7uF
Figure 1.1 Connection Diagram - Full Options
+2.8 ~ +5V
Voltage Reg
*4.7uF
VDD
*100nF
* Note: one bypass capacitor to be tightly wired
between Vdd and Vss. Follow manufacturer’s
recommendations for input and output capacitors.
KEY 3
KEY 4
KEY 5
KEY 6
KEY 7
SYNC or LP IN
DETECT OUT
Keep these parts
close to the IC
Keep these parts
MOD_1
1M
3
2
close to the IC
Vdd / Vss
12 _{SNS3 VDD}
1nF ^CS3
RSNS3
13 _SNS3K
10K
POL
1M
Vdd / Vss
1nF CS4
RSNS4
14 _SNS4
15 _SNS4K
/RST _SNS2K 11 ^1nF
CS2 _RSNS210K
SNS2 ¹⁰
1M _{MOD_0}
SNS1K ⁹
SNS1 ⁸
1nF
Vdd / Vss
CS1 _RSNS1^10K
1M _{AKS_1}
Vdd / Vss
KEY 2
KEY 1
10K
OUT_D
1M
Vdd / Vss
1nF
RSNS5
10K
SL_0
1M
Vdd / Vss
1nF
RSNS6
16 _SNS5
SNS0K ⁷
SNS0 ⁶
1nF
CS0 _RSNS010K
1M _{AKS_0}
KEY 0
SNS5K
VDD
Vdd / Vss _{Recommended Rb1, Rb2 Values}
Vdd Range Rb1 Rb2
2.8 ~ 3.59V 12K 22K
18
SNS6 _QT1081
19 _{SNS6K 32-QFN}
Rb1
OSC ⁴
Rb2
3.6 ~ 5V 15K 27K
The required value of spread-spectrum capacitor CSS
will vary according to the lengths of the acquire bursts,
see Section 3.2. A typical value of CSS is 100nF.
10K
SL_1
1M
Vdd / Vss
20
SNS7
RSNS7 ^{1nF CS7} ₂₁
SNS7K
SS ¹
CSS
OUT_7 ³²
OUT_6 ³¹
OUT_7
OUT_6
10K
OUT_5 ³⁰
OUT_5
22
VSS
OUT_4 ²⁹
OUT_3 ²⁸
OUT_4
OUT_3
23
SYNC/LP
24 _DETECT
OUT_2 ²⁷
OUT_1 ²⁶
OUT_0 ²⁵
OUT_2
OUT_1
OUT_0
Binary coded
output mode
Table 1.2
AKS / Fast-Detect Options
Table 1.3
Max On-Duration
Table 1.4
Polarity and Output
Table 1.5
SYNC/LP Function
AKS_1
Vss
Vss
Vdd
Vdd
MOD_1
Vss
Vss
Vdd
Vdd
OUT_D
Vss
Vss
Vdd
Vdd
SL_1
Vss
Vss
Vdd
Vdd
AKS_0
Vss
Vdd
Vss
Vdd
AKS MODE
Off
Off
On, in 2 groups
On, global
FAST-DETECT
Off
Enabled
Off
Off
MOD_0
Vss
Vdd
Vss
Vdd
MAX ON-DURATION MODE
10 seconds (nom) to recalibrate
60 seconds (nom) to recalibrate
Infinite (disabled)
(reserved)
POL
Vss
Vdd
Vss
Vdd
OUT_n, DETECT PIN MODE
Binary coded, active high, push-pull
One-per-key, active low, open-drain
One-per-key, active high, push-pull
One-per-key, active low, push-pull
SL_0
Vss
Vdd
Vss
Vdd
SYNC/LP PIN MODE
Sync
LP mode: 100ms nom response time
LP mode: 180ms nom response time
LP mode: 340ms nom response time
lQ
6
QT1081_1R0.04_0307