ACT8840
Rev 2, 29-Jan-15
PWM LED DRIVERS
Table 5:
GPIOx/DUTY[ ] PWM Frequency Setting
The GPIO1, the GPIO2, 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
0010
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 4.
0011
0100
31.25
37.5
43.75
50
0101
Table 4:
0110
GPIOx/FRE[ ] PWM Frequency Setting
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
1111
PWM Duty Cycle Selection
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 5.
Innovative PowerTM
- 37 -
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