QT60240-ATG Datasheet, PDF (24/26 Pages) List of Unclassifed Manufacturers – 16 AND 24 KEY QMATRIX TOUCH SENSOR ICs

7.5 Power Consumption
Table 7.1 Average Current Consumption
Test condition: BL = 48, 16 or 24 keys enabled (see appropriate column)
Voltage (V)
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
1.8
3.3
5.0
Sleep
Setting (ms)
16
32
64
125
250
500
1000
2000
Idd Typical (mA)
24 keys
0.480
1.050
1.900
0.300
0.670
1.220
0.170
0.350
0.730
0.090
0.220
0.400
0.050
0.120
0.240
0.043
0.090
0.160
0.040
0.080
0.130
0.039
0.075
0.120
16 keys
0.360
0.840
1.550
0.250
0.540
0.910
0.150
0.310
0.550
0.080
0.170
0.300
0.048
0.100
0.160
0.040
0.060
0.110
0.038
0.053
0.100
0.037
0.050
0.095
The formula to find the average current is:
Idd = (current sleeping x sleep period) + (current running x (burst spacing x number of keys enabled))
sleep period + (burst spacing x number of keys enabled)
Idd = (Idds x Tsleep) + (Iddr x (TBS x KE))
Tsleep + (TBS x KE)
Note: there may be more than one inst ance of (TBS x KE)
(see example below)
Where:
Idd
= average current (mA)
Idds = current when sleeping (mA)
(Section 7.3)
Tsleep = sleep period (ms)
(Table 6.2)
Iddr = current when running (mA)
(Section 7.3)
TBS
= burst spacing¹ (ms)
(Section 7.4)
KE
= number of keys enabled¹
1 _{if more than one burst spacing is used then each must be}
included in the calculation.
Example: Conditions: Vdd = 1.8V, 10 keys BL = 32, 14 keys BL = 16, Tsleep = 125ms
Idd = (0.003 x 125) + (1.02 x ((0.38 x 10) + (0.27 x 14))) = 0.06115mA = 61.15µA
125 + ((0.38 x 10) + (0.27 x 14))
lQ
24
QT60240-ISG R8.06/0906