JAJSKE4 March 2021 TPS92391
PRODUCTION DATA
The LED dimming frequency is asynchronous from the input PWM frequency for phase-shift PWM mode and hybrid dimming mode. The LED dimming frequency is generated from the internal 20-MHz oscillator and can be set to eight discrete frequencies from 152 Hz to 19.531 kHz. The PWM dimming resolution is highest when the lowest PWM frequency is used. The PWM_FSET resistor determines the LED Dimming frequency based on Table 7-8. Resistor with 1% accuracy is needed to ensure proper operation. PWM resolution in Table 7-8 is with PWM dither disabled.
R_PWM_FSET (kΩ) | LED PWM FREQUENCY (Hz) | PWM DIMMING RESOLUTION (bits) |
---|---|---|
3.92 | 152 | 16 |
4.75 | 305 | 16 |
5.76 | 610 | 15 |
7.87 | 1221 | 14 |
11 | 2441 | 13 |
17.8 | 4883 | 12 |
42.2 | 9766 | 11 |
124 | 19531 | 10 |