Saket Vora

So tomorrow school starts up again. Short day cause I woke up really late. It’s going to be a busy two weeks….the waiting before I get reamed on my final exams.

I watched the championship game of the Old Spice classic — NC State vs #19 Villanova. I’m not sure when I’ll get to see NC State play on ESPN2 again. It was a nailbiter. Being an NC State fan is a trial of faith. We gained the lead at the half, but Villanova kept chipping away at it. The last several minutes we were in a drought. Villanova goes up by 1 point with 2.2 seconds left. But then, on the inbound, Gavin Grant is fouled when going for the three! He misses the first, makes the next two for the go-ahead score. Villanova has 0.4 seconds, and despite the ball nearly going in, the Wolfpack came away with the win.

Later, I was watching most of the Eagles vs Patriots game. It was amazing — the Eagles were playing their best game in a while and was even leading going into the end of the 4th quarter. But then the QB gave up a bad interception on an unnecessary pass, and the Patriots scored to ultimately win it.

In other news, we have a much more optimized design for the 214 project! The last post showed a power dissipation of 47.27 mW. By implementing a real bias network and fine-tuning some values (trial and error Spice monkeying!) I was able to get:

The following specs were measured using our scripts.Description:                 Achieved

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Settling Time (ns):     39.31

Static Error (%):     -0.010

Dynamic Range (dB):     90.10

Power (mW):             21.85

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Congtratulations! Your design has met the spec  :) 

21.85 mW now! We are well within the 0.025% static error requirement. I can reduce the settling time (the spec is 40ns) but that will take more power. I am still very unhappy with a parameter known as the phase margin, which is measured in degrees. I was designing for a phase margin of 75 degrees. Many of the resulting parameters my design process calculated were matched in simulation. Yet, my phase margin is only 41 degrees. This is bad: not only do you want your phase margin to ensure stability for your amplifier, but a phase margin of 75 degrees also improves settling time. If I can somehow get my phase margin higher, I might be able to further reduce the power while meeting my specifications. This tells me that I am neglecting to factor in some rather important parameters into my design process. I need to read up on frequency response of two-stage telescopic OTAs.

Two random ways to finish this post. I’ve been lately listening to Bloc Party’s Silent Alarm, and here is a picture of my Vista’s sidebar….how I’m keeping track of people.