AAT3193 Datasheet, PDF (11/18 Pages) Advanced Analogic Technologies – 3-Channel Charge-Pump LED Driver

ChargePump^TM
Data
1
2
3
4
5
6
7
8
EN Rising Edges
1
2
3
4
5
6
7
8
D1-D3 Current (mA)
20
17.3
14.7
12
9.3
6.7
4
1.3
Table 2: AAT3193-2 LED Current Settings.
20.00
15.00
10.00
5.00
0.00
1
2
3
4
5
6
7
8
S²Cwire Interface Data Code
Figure 3: AAT3193-2 Current Control Profile.
Data
1
2
3
4
EN Rising Edges
1
2
3
4
D1-D3 Current (mA)
20
13.3
6.7
0.87
Table 3: AAT3193-3 LED Current Settings.
20.00
15.00
10.00
5.00
0.00
1
2
3
4
S²Cwire Interface Data Code
Figure 4: AAT3193-3 Current Control Profile.
PRODUCT DATASHEET
AAT3193
3-Channel Charge-Pump LED Driver
PWM Control (AAT3193-4 only)
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.
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
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
D1-D3 Current (mA)
20
17.9
15.9
14
12.1
10.1
8.2
6.3
4.3
2.4
Table 4: AAT3193-4 LED Current Settings
(R_SET = 14.3kW, f_PWM = 50kHz).
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 (%)
Figure 5: AAT3193-4 Current Control Profile
(R_SET = 14.3kΩ, f_PWM = 50kHz).
3193.2008.07.1.3
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