E6240 Atmel, E6240 Datasheet - Page 24

• Manufacturer Part Number: E6240
• Description: KIT EVAL/DEV USING QT60240-ISG
• Manufacturer: Atmel
• Series: Quantum, QMatrix™r

Specifications of E6240

• Sensor Type: Touch, Capacitive
• Sensing Range: 16 / 24 Buttons/Keys
• Interface: I²C, USB
• Voltage - Supply: 5V
• Embedded: No
• Utilized Ic / Part: QT60160, QT60240
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -

7.5 Power Consumption
The formula to find the average current is:
Example: Conditions: Vdd = 1.8V, 10 keys BL = 32, 14 keys BL = 16, Tsleep = 125ms
lQ
Where:
Idd
Idds
Tsleep
Iddr
T
KE
1
BS
if more than one burst spacing is used then each must be
included in the calculation.
Idd = (current sleeping x sleep period) + (current running x (burst spacing x number of keys enabled))
Idd = (Idds x Tsleep) + (Iddr x (T
Idd = (0.003 x 125) + (1.02 x ((0.38 x 10) + (0.27 x 14))) = 0.06115mA = 61.15µA
=
=
=
=
=
=
average current (mA)
current when sleeping
sleep period
current when running
burst spacing
number of keys enabled
Tsleep + (T
Test condition: BL = 48, 16 or 24 keys enabled (see appropriate column)
125 + ((0.38 x 10) + (0.27 x 14))
Voltage (V)
(
sleep period + (burst spacing x number of keys enabled)
1
ms
Table 7.1 Average Current Consumption
(ms)
BS
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
)
x KE)
(
mA
(
BS
mA
1
x KE))
)
)
Setting (ms)
Sleep
1000
2000
125
250
500
(Section 7.3)
(Table 6.2)
(Section 7.3)
(Section 7.4)
16
32
64
24
Note: there may be more than one inst ance of (T
24 keys
(see example below)
Idd Typical (mA)
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
QT60240-ISG R8.06/0906
BS
x KE)