Hi All,
Looks like I=92ve got a new little project designing a pulse amplifier for a PMT. I=92m thinking of something like this,
PMT C~0.01u |\ Anode O----||--+-(+) >- (Repeat amp stage.) | |/ R1 R1 | GND The PMT is a Hamamatsu R212, with negative high voltage on the dynodes so the anode is near ground. I=92m going to try AD8001=92s for the amplifiers. (Following suggestions by John L.) I=92ve never used a CFA before so there is a little something new for me to learn.
With R1=3D 50 ohms I=92ve got about* 1mV /10ns pulses at the amp input. I=92d like to get the pulses up to the ~100mV level. The amp will sit right next to the PMT so there is no reason I can=92t increase R1 and get a bit more gain that way.
Just wondering if there is some other circuit configuration I might consider. (Since it=92s a current pulse from the PMT would a TIA be better?)** And any gotcha=92s with the CFA? (I=92ve got to read a bit more by S. Franco on CFA=92s before picking resistor feedback values.)
Thanks, George H.
*(I looked at this a year ago, but didn=92t write the numbers down in my notebook...sigh. But I could see things on a =91scope.)** can I cram the current pulse into the (-) input of the CFA with perhaps a 1k ohm feed back resistor and then a second stage voltage amp?