Is 28nm LP obsolete?

[lefty]

Considering the new processes available, like HPM, HPC and HPC+, I am wondering if the origonal 28nm LP and HP has become obsolete. I mean would these even be considered anymore for new tape outs?

 

[Daniel Payne]

Great question and one that comes down to your SoC requirements and then foundry pricing, availability, delivery times and volume.

LP was designed as a first generation of 28 nm to enable low power applications like cellular baseband.

HPL gets you lower leakage numbers.

HPM is tuned for high performance mobile chips.

HPC has a smaller cell size for cost-sensitive designs.

TSMC has an interesting comparison chart here.

 

[tranvanle.dhbk]

Great question and one that comes down to your SoC requirements and then foundry pricing, availability, delivery times and volume.

LP was designed as a first generation of 28 nm to enable low power applications like cellular baseband.

HPL gets you lower leakage numbers.

HPM is tuned for high performance mobile chips.

HPC has a smaller cell size for cost-sensitive designs.

TSMC has an interesting comparison chart here.

And ULP for ultra Low power consumption design as well with extrem high VT devices type.

 

[khaki]

Any of the newer offerings will be lower power than LP. It was a low-cost early version that did not have high-k metal gate and has limited number of devices. I think Renesas' 28nm embedded memory (presented at ISSCC'15) is developed on 28LP, but am not sure. Serious ULP applications need very low Vt to enable low Vdd operation. Adding higher Vt, although seems natural, defeats the purpose.