SM320F2812-HT: Are the SM320F2812-HT or SM320F28335-HT recommended for new designs?

Pierce,

You are correct that the F28335 is the newer of the two devices you have listed.  From a purely technical standpoint, ADC accuracy, ePWM capability, the F28335 has better specs vs the F2812; so for a new design I would pick the F28335 based on that alone.  Neither of these devices is planned for obsolescence, I will go into more detail below.

To address your concern on obsolescence TI has several conditions that must be met in order to consider this path and then execute it.  I will refer this website which has our official policy; https://www.ti.com/support-quality/quality-policies-procedures/product-life-cycle.html 

The first bullets on the above page are as follows and copied below:  I can verify that both of these devices have active customers and shipments today, so per the below we would have minimum of 7 years of production assuming we had no more orders, etc.  There is more explanation of our notification process in the above link, and I'll let you read through that if you have more concerns.

Our guidelines state that TI standard products are not eligible for obsolescence if any of these three conditions exist:

• The product has had any sales within the last five years (seven years for automotive or high-reliability products).
• The product can be manufactured and has been in production for less than 10 years.
• The product has any current customer demand.

Best,
Matthew