PRODUCT DATASHEET
AAT3193
TM
ChargePump
3-Channel Charge-Pump LED Driver
PWM Control (AAT3193-4 only)
Data
EN Rising Edges
D1-D3 Current (mA)
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
20
17.3
14.7
12
9.3
6.7
4
PWM (Pulse Width Modulation) is an industry standard
technique of controlling LED brightness by modulating
the conduction duty cycle of the LED current. LED
brightness is determined by the average value of the
PWM signal multiplied by the LED’s intensity where
intensity is proportional to the LED drive current. A PWM
control signal can be applied into the EN/PWM pin of the
AAT3193-4. By changing the duty cycle of the PWM sig-
nal from 100% (logic high) to 10%, LEDs sink current
can be programmed from 20mA to 2.4mA. To save
power when not used, AAT3193-4 can be shutdown by
holding the EN/PWM pin low for 1ms.
1.3
Table 2: AAT3193-2 LED Current Settings.
20.00
15.00
10.00
5.00
Lastly, Table 4 and Figure 5 illustrate the AAT3193-4’s
LED current control profile as a function of a PWM con-
trol signal.
EN/PWM Duty Cycle
D1-D3 Current (mA)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
20
17.9
15.9
14
12.1
10.1
8.2
6.3
4.3
2.4
0.00
1
2
3
4
5
6
7
8
S2Cwire Interface Data Code
Figure 3: AAT3193-2 Current Control Profile.
Data
EN Rising Edges
D1-D3 Current (mA)
1
2
3
4
1
2
3
4
20
13.3
6.7
Table 4: AAT3193-4 LED Current Settings
(RSET = 14.3kW, fPWM = 50kHz).
0.87
20.00
15.00
10.00
5.00
Table 3: AAT3193-3 LED Current Settings.
20.00
15.00
10.00
5.00
0.00
100% 90% 80% 70% 60% 50% 40% 30% 20% 10%
EN/PWM Input Pin Duty Cycle (%)
0.00
1
2
3
4
Figure 5: AAT3193-4 Current Control Profile
S2Cwire Interface Data Code
(RSET = 14.3kΩ, fPWM = 50kHz).
Figure 4: AAT3193-3 Current Control Profile.
w w w . a n a l o g i c t e c h . c o m
3193.2008.07.1.3
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