I received my TPS92411 EVM-001 today and have it hooked up to a generic triac dimmer. I notice that there seems to be some significant hysteresis between going up and going down in brightness. Going down in brightness is very smooth and it can go down to very low light level. But if I go down to no light with the rotary control, then as I rotate the control clockwise to increase brightness again, I must turn the level control about 1/4 turn to get any light, and it then comes on bright. Trying to understand what is going on, if this is an artifact of a cheap triac driver or something having to do with the 92411 driver ICs. Any suggestions? thanks.
By the way, I am very impressed by the very low (non visible!) and consistent level of light modulation as the EVM board is dimmed. I am looking at a photo detector on my scope, and the percentage of optical ripple is quite constant throughout the dimming range. Well done! This is a very important aspect to my client, as these lights will be going into ceiling fans, where flicker causes very visible strobing effects.
