ACT8847
Rev 5, 15-Nov-12
PWM LED DRIVERS
Table 7:
GPIOx/DUTY[ ] PWM Frequency Setting
The GPIO3, the GPIO4, the GPIO5, and the GPIO6
are configured as PWM LED drivers, which could
support up to 6mA current with programmable
frequency and duty cycle. Set PWMxEN[ ] bit to “1”
to enable PWM function of GPIOx.
GPIOx/DUTY[3:0]
0000
PWM Duty Cycle [%]
6.25
12.5
18.75
25
0001
PWM Frequence Selection
Each LED driver may be independently
programmed to a different frequency by writing to
the GPIO’s FRE[2:0] register via the I2C serial
interface as shown in Table 6.
0010
0011
0100
31.25
37.5
43.75
50
Table 6:
0101
GPIOx/FRE[ ] PWM Frequency Setting
0110
0111
GPIOx/FRE[2:0]
PWM Frequency [Hz]
1000
56.25
62.5
68.75
75
000
001
010
011
100
101
0.25
0.5
1
1001
1010
1011
2
1100
81.25
87.5
93.75
100
128
256
1101
1110
PWM Duty Cycle Selection
1111
Each LED driver may be independently
programmed to a different duty cycle by writing to
the GPIO’s DUTY[3:0] register via the I2C serial
interface as shown in Table 7.
Innovative PowerTM
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