Tool/software:
Hi TI Team,
We are using the TPS923653 for LED Backlight control. We are using the Hybrid dimming mode where ADIM is low and PWM/EN pin has a 10kHz PWM signal on it. There are two oddities we are encountering:
1. The threshold for switching from PWM output on SW to current limited output is around 25% duty cycle. According to the datasheet we expect 12.5%
2. The backlight is not turning on when switching from 0% to 99%, with a measured 400ns low pulse, according to the datasheet hybrid dimming should be enabled by the first falling edge on PWM/EN, and the minimum pulse time is 150ns. Inspecting the signal on a scope indicates that this is a clean falling edge of more than sufficient duration.
Are there any explanations for these behaviors or any way that we can mitigate them, i.e. changing the PWM frequency or doing something else in startup?
Thank you,
Sam
