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I'm sorry but no. Unless you are producing a 1930s radio these sorts of schematics are next to worthless. There's nothing super clever about PCB routing or re

I'm sorry but no. Unless you are producing a 1930s radio these sorts of schematics are next to worthless. There's nothing super clever about PCB routing or resistor placement and it is completely dependent on the chips used (which are increasingly including the actual resistors and capacitors internal to the chip). Consider, for example, how useful this schematic would be vs an AMD motherboard schematic. You imagine that because apple has a bunch of money to spend that they are spending more than a competitor would on PCB design. But that's just not how hardware works. The money Apple is spending on R&D is almost entirely going into the design of their M series chips and their software/firmware.

varispeed 1y ago
This dismisses the entire field of modern high-speed digital design. At GHz frequencies, the PCB isn't a passive substrate; it's an active RF component. Managing signal integrity, controlling impedance, and mitigating EMI in a dense layout is a monumental engineering challenge, not a solved problem from the "1930s radio" era. The AMD comparison is backward. AMD provides public datasheets and reference designs. This schematic is valuable precisely because Apple's silicon is a black box. It's the only public blueprint for a successful, validated implementation. The chip and board are a co-designed system. A brilliant SoC is useless without the board-level engineering to power it cleanly and cool it within a tiny physical envelope. That system integration is the R&D.
- throwaway31131 1y ago
  But all that information is in the engineering files that are neither the schematic or the layout. You might guess some information from the layout, but on some crazy HDI PCB like the iPhone uses, you'll be missing most of the information needed to take advantage of it. Any signal that uses passive termination, and would therefore show up in the schematic, is basically a tacit admission that this line needs something, but basically anything remotely close to 50Ω will do. Which is something you could've gathered by inspection of the final product.
- cogman10 1y ago
  > This dismisses the entire field of modern high-speed digital design. No it doesn't. That entire field operates primarily within the ASICs, not the PCB. > At GHz frequencies, the PCB isn't a passive substrate; Yes, it actually is. There is some noise and cross talk that's emitted from the signals but it's minimal and easily blocked. Very simple rules, like minimum trace distances, solve pretty much any problem that comes up from the frequency of the signals. But further, those problems are peanuts compared to dealing with the exact same problem within the ASIC. Very simple rules are needed for the PCB. > mitigating EMI in a dense layout is a monumental engineering challenge, not a solved problem from the "1930s radio" era. You are vastly overblowing how big an issue or problem this is. The voltages and current on the lines are minimized to cut back on EMF and power consumption. Those are dictated by the chip design, not the PCB setup. > A brilliant SoC is useless without the board-level engineering to power it cleanly and cool it within a tiny physical envelope. That system integration is the R&D. There is some R&D that goes into the board, for sure. However you are completely overblowing how hard or costly it is for apple or others to develop.
  - varispeed 1y ago
    This demonstrates a profound misunderstanding of the physics of high-speed electronics. High-speed design doesn't stop at the ASIC boundary; that's often where the hardest part begins. The entire field of SerDes engineering exists to solve the "trivial" problem of getting multi-gigabit signals off the chip and across the board to RAM or a port without dissolving into noise. It's a system-level challenge. At GHz frequencies, a PCB trace is not a passive wire; it is a transmission line. The idea that "simple rules" for trace distance solve this is fundamentally incorrect. Real-world design requires complex electromagnetic simulation to control impedance, manage signal reflections, and design via structures that don't destroy the signal. This is why Signal Integrity (SI) is a dedicated engineering discipline. EMI is caused by the rate of change of current (dI/dt), not just the voltage level. Modern chips have incredibly fast signal rise/fall times to achieve high performance, which creates massive high-frequency energy that radiates easily. Passing FCC/CE certification is a famously difficult, multi-million-dollar R&D effort, not a trivial detail.
    - 1y ago

varispeed 1y ago

This dismisses the entire field of modern high-speed digital design. At GHz frequencies, the PCB isn't a passive substrate; it's an active RF component. Managing signal integrity, controlling impedance, and mitigating EMI in a dense layout is a monumental engineering challenge, not a solved problem from the "1930s radio" era. The AMD comparison is backward. AMD provides public datasheets and reference designs. This schematic is valuable precisely because Apple's silicon is a black box. It's the only public blueprint for a successful, validated implementation. The chip and board are a co-designed system. A brilliant SoC is useless without the board-level engineering to power it cleanly and cool it within a tiny physical envelope. That system integration is the R&D.

throwaway31131 1y ago
But all that information is in the engineering files that are neither the schematic or the layout. You might guess some information from the layout, but on some crazy HDI PCB like the iPhone uses, you'll be missing most of the information needed to take advantage of it. Any signal that uses passive termination, and would therefore show up in the schematic, is basically a tacit admission that this line needs something, but basically anything remotely close to 50Ω will do. Which is something you could've gathered by inspection of the final product.
cogman10 1y ago
> This dismisses the entire field of modern high-speed digital design. No it doesn't. That entire field operates primarily within the ASICs, not the PCB. > At GHz frequencies, the PCB isn't a passive substrate; Yes, it actually is. There is some noise and cross talk that's emitted from the signals but it's minimal and easily blocked. Very simple rules, like minimum trace distances, solve pretty much any problem that comes up from the frequency of the signals. But further, those problems are peanuts compared to dealing with the exact same problem within the ASIC. Very simple rules are needed for the PCB. > mitigating EMI in a dense layout is a monumental engineering challenge, not a solved problem from the "1930s radio" era. You are vastly overblowing how big an issue or problem this is. The voltages and current on the lines are minimized to cut back on EMF and power consumption. Those are dictated by the chip design, not the PCB setup. > A brilliant SoC is useless without the board-level engineering to power it cleanly and cool it within a tiny physical envelope. That system integration is the R&D. There is some R&D that goes into the board, for sure. However you are completely overblowing how hard or costly it is for apple or others to develop.
- varispeed 1y ago
  This demonstrates a profound misunderstanding of the physics of high-speed electronics. High-speed design doesn't stop at the ASIC boundary; that's often where the hardest part begins. The entire field of SerDes engineering exists to solve the "trivial" problem of getting multi-gigabit signals off the chip and across the board to RAM or a port without dissolving into noise. It's a system-level challenge. At GHz frequencies, a PCB trace is not a passive wire; it is a transmission line. The idea that "simple rules" for trace distance solve this is fundamentally incorrect. Real-world design requires complex electromagnetic simulation to control impedance, manage signal reflections, and design via structures that don't destroy the signal. This is why Signal Integrity (SI) is a dedicated engineering discipline. EMI is caused by the rate of change of current (dI/dt), not just the voltage level. Modern chips have incredibly fast signal rise/fall times to achieve high performance, which creates massive high-frequency energy that radiates easily. Passing FCC/CE certification is a famously difficult, multi-million-dollar R&D effort, not a trivial detail.
  - 1y ago