Behind The Analog Frenzy

Analog is suddenly very hot again, and much of it appears to be due to the promise of 2.5D and 3D stacking.

Texas Instruments pulled out its checkbook to pay $6.5 billion for National Semiconductor, and Microsemi has offered $28 million for AML Communications, which makes low-noise and high-power microwave amplifiers.

So what’s behind these move? In TI’s case, there appears to be a recognition that if analog can be put on a separate die then TI will be able to offer full subsystems or chips for specific vertical markets. When you think about it, that’s a lot more profitable than a team of engineers trying to retrofit analog functionality on 28nm or 22nm processes. Analog processes can survive for 10 years or more. Digital processes are turned over at the rate of Moore’s Law.

In the early part of the 00 decade, analog companies had largely given up on mixed signal processors because they were too hard to integrate. They changed their minds in the latter part of the decade as the smart phone revolution drummed up enough demand to warrant the investment. But the future appears to be a return to separate chips bound together by either a silicon interposer or through-silicon vias.

That makes analog designers far more important than they were a year ago, and it makes them far more valuable. TI hasn’t paid this much money for analog talent since it bought Burr-Brown in 2000 for $7.6 billion.

In Microsemi’s case, microwaves are becoming much more popular for advanced communications—particularly in the military space where terahertz clock frequencies are under development. At these kinds of speeds signal integrity is a challenge using standard RF technology.

What’s making these terahertz frequencies possible is a new metal-insulator-insulator-metal stack—a not-so-simple concept when you consider these designs suffer from some of the same kind of thermal issues as other stacked die. Putting two insulation layers together can create heat problems that require some sophisticated venting concepts.

We expect to see more consolidation in both of these spaces, and far more vertical solutions that can be quickly assembled with other die to reduce time to market significantly. While these are large sums of money, the acquisition frenzy appears to be just getting started.

–Ed Sperling