Jeff Geerling

Coolest tech I found at #NAB today — 8-channel TV tuner ATSC 3.0 card from SiliconDust; for control over PCIe uses an RP2350 (4x UARTs)z

Got to talk to Nick Kelsey (President/CTO) about it!

Apr 22 at 1:46amIvory for iOS
Show threadNick 🦇🕸️🖤🖖Apr 22
@geerlingguy nice 8-way resistive divider. Looks like an LNA at the RF input and a matching network right before each tuner IC. Is the RP2350 tied into the I2C SMBus? I think that's available on each PCIe slot?
Show threadavianApr 22

@ExplodingLemur @geerlingguy Also interesting they seem to have one oscillator per two tuners.

Why didn't they drive all tuners from a single clock source?

I remember NXP TV tuner ICs I worked with had an application circuit with two tuners running off one crystal, but afaik there was no technical reason not to drive more.

I wonder if these Sony ICs had the same and they just went with the documented circuit and didn't want to try optimizing it further.

Show threadFlakiApr 22
@geerlingguy wait how come? Wikipedia lists 2 UART-s for the RP2350..?
Show threadKevin P. FlemingApr 22
@flaki @geerlingguy PIO blocks can be used as UARTs too.
Show threadJeff GeerlingApr 22
@flaki 2 more via PIO