azonenberg changed the topic of #scopehal to: libscopehal, libscopeprotocols, and glscopeclient development and testing | | Logs:
juli966 has quit [Quit: Nettalk6 -]
electronic_eel has quit [Ping timeout: 264 seconds]
electronic_eel_ has joined #scopehal
Degi_ has joined #scopehal
Degi has quit [Ping timeout: 264 seconds]
Degi_ is now known as Degi
<azonenberg> AKL-AD1 prototype assembled
<azonenberg> About 17 mV of DC offset. I'm sure i could improve this with some sort of calibration
<azonenberg> There's a weird artifact on the falling edges i need to investigate
azonenberg_work has quit [Ping timeout: 265 seconds]
<azonenberg> Ok so, back to basics... When powered up, it pulls about 82 mA from both the +2.5V and -2.5V rails
<azonenberg> With both inputs terminated with 50 ohms to ground, and the output terminated with 50 ohms to ground, I measure 15.26 mV offset at the output
<azonenberg> With no load on the output (high Z) I measure 19.2 mV offset
<azonenberg> aaand it looks like i need to put shielding on the probe lol
<azonenberg> i did a noise spectrum
<azonenberg> and saw a nice big 2.4 GHz peak
electronic_eel_ has quit [Quit: - Chat comfortably. Anywhere.]
electronic_eel has joined #scopehal
<azonenberg> lain: S21 of AKL-AD1 from P/N inputs to output with SMA DC block on output, and other output terminated into ground with a capacitor + 50 ohms
<azonenberg> apparently this amp doesn't like the output being DC coupled to ground, despite the docs saying it's fine as long as the common mode is compatible
<azonenberg> i think what's happening is that the natural common mode offset of the amp is causing a DC current flow, so i could probably get away with DC coupling the output if I carefully tuned Vcm with a DAC to null out the offset of the internal Vcm buffer
<azonenberg> But realistically for high speed work, i think an AC coupled amplifier is fine. What I'm less thrilled at is the mismatching between P and N
<azonenberg> From 350 MHz to 1.2 GHz they're very well matched
<lain> :o
<lain> yeah o.o
<azonenberg> I'm also trying to figure out how to properly merge a bunch of 2-port s-parameter measurements into a s3p/s4p
azonenberg_work has joined #scopehal
<azonenberg> lain: also ^
<azonenberg> interesting rising vs falling edge asymmetry
<lain> oo, interesting indeed
juli966 has joined #scopehal
juli966 has quit [Quit: Nettalk6 -]
jn__ has quit [Ping timeout: 272 seconds]
jn__ has joined #scopehal