before entering in to problem:
my application is a laser pulse detection, in this process when a laser pulse falls on photo diode it generates current, later stages include a I-V conversion, Gain,difference amplifier and comparator
my pulse characteristics:
pulse width min:10ns max:150ns rise/fall time:2ns-5ns pulse to pulse width:22uS
How i selected the opamp for Gain and difference amplifier stages
key parameters: BW - bandwidth and SR - Slew Rate
from this literature i found my BW can be calculated by formula
BW=0.35/(rise time)=0.35/5ns=70MHz
Now slew rate is to be calculated
SR = 2 * 3.14* BW * Vp = 2 * 3.14* 175MHz *4V = 2198V/us
So Matching both these parameters is a CFA AD8003 from Analog, when i go for high slew rates and high BW almost all opamps avaliable are CFA's !
here below is the desing as suggested in datasheet, pulse here is a 10ns pulse with 100ns repetetion and 1V amplitude fromt the voltage source, i used the TIs TINA simulation and imported the spice model given by Analog Devices
results are quite unexpected
Attachment is the design of the above circuit which can be opened and simulated using TINA, because i did not find AD8003 in analog simulator and i was not able to import the spice model to ADI simulator
Kindly help in taking the advantage of AD8003
