IHP open source 130 nm BiCMOS PDK with 500 GHz fmax transistors | Hacker News Reader

IHP open source 130 nm BiCMOS PDK with 500 GHz fmax transistors

github.com

53 pointshenrikf12 comments

This is a very fast BiCMOS process with both MOSFETs and bipolar transistors. Some digital logic can be implemented with MOSFETs but since they are 130 nm it's not very competitive with smaller cutting edge CMOS processes. Bipolar transistors are really the whole point of choosing this process and it's aimed for implementing analog and RF circuits. Bipolar transistors are extremely fast and can be used to make amplifiers operating at >200 GHz. MOSFETs can be used to implement some simple digital blocks for controlling the RF blocks.

I have made several tapeouts with this process and I have very good experiences with it. Compared to other open source PDKs that Google has open sourced previously this one is quite modern and offers very good RF performance.

It doesn't seem quite ready for design yet. Transistor models and stackup are published so schematic level simulation is possible. There is a roadmap chart in the repository (https://github.com/IHP-GmbH/IHP-Open-PDK/blob/main/ihp-sg13g...) and it seems that they are going to offer free MPW runs.

Isn't this what's used for military applications like AESA radars? If so how come it's open source?

What's open sourced here is the design kit. Designed chips need to be sent to IHP to be manufactured.

SiGe isn't also that useful for military radar applications. Compared to SiGe GaN has much greater breakdown voltage which leads to greater output power and better efficiency. It's possible to get 10 to 100 times more output power from GaN chip compared to SiGe. It isn't really possible to make high performance long range radar with just SiGe although it could be used in some parts of it.

Is there any FOSS you can use these PDKs with?

For this PDK there is only limited support (it is only in preview!) for klayout and ngspice - which are a FOSS layout tool and circuit simulator respectively. If you want to play with whats available, someone put up a colab script here:

https://colab.research.google.com/gist/proppy/f63686b02309e2...

The other two open PDKs, SKY130 and GF180MCU, have a more complete ecosystem the major tools being the opencircuitdesign suite, xschem and the OpenRoad project. If you're still interested, there's an easy to use docker container that has most of the tools in question already installed:

https://github.com/iic-jku/iic-osic-tools

This is great! I love seeing new open pdks. It's still a pain to use these for complex analog design, compared to something from tsmc or samsung, but every step is progress in the right direction.

Dumb question: if this can be used for 200 GHz electronics, why is it not useful for digital electronics? Is the power draw prohibitive or something?

Almost all logic today is done using CMOS for power reasons. The 200+ GHz stuff is all BJT, which while remarkably fast and less noisy, is generally much more power intensive (orders of magnitude). This makes BJT based designs useful for small to medium analog / RF blocks but not useful for designing a full blown modern microprocessor.

This process integrates both (pretty difficult to do for various physical process reasons) which allows you to combine the CMOS for things like power control and logic alongside the BJTs for extremely high speed analog circuitry.

200 ghz analog amplifiers, not 200 ghz digital logic. Very different circuit design rules.

Nice! I wonder whether there will also be public MPW shuttles?

Also, curious whether open tools suitable for HF design are available that could be used with this PDK.

Russia and other rogue states must certainly love this release...

Why? They don’t have technology for manufacturing anyway.

Reply on news.ycombinator.com