TLC59731: What is the difference between TLC5973DR and TLC59731DR?

Tool/software:

Hello,

I'm comparing TLC5973DR and TLC59731DR for an RGB LED control project using 1-wire communication.

I noticed that both devices support 1-wire serial input (SDI), but there are differences in current control and internal architecture.
From what I understand:

• TLC5973DR has an IREF pin that allows setting the maximum output current per channel using an external resistor.

• TLC59731DR, on the other hand, seems to lack IREF functionality and uses a fixed current internally.

Could you please clarify the exact functional differences between these two chips?

Also, are there any other TI solutions that support 1-wire LED control (especially for RGB applications) with external current control like TLC5973?

Thank you!