LT 1028 OP AMP QUESTION

[Davor]

It does. AD845 is nearly perfect for PI. A bit noisy, but otherwise perfect. AD797 is also very fast NPN input op amp and has much lower noise, but you can't put it into Surf without compensation redesign.

[Carl-NC]

You also should look at overvoltage recovery. This is almost never spec'd so you have to test it yourself.

[kt315]

Carl, in the second edition will be all answers on Dave's questions? can he wait all objective globalcovering information some kinda FAQ in the copy?

[daverave]

ive just ordered a couple of the AD 845 op amps and do some experimenting when i receive them in about 3 weeks as coming from abroad...does the AD 845 need compensation redesign if put into the surf pi ???

[kt315]

i still remember anyone used AD8055 (WOW! 1400V/us slew rate!) in HH board but i do know what result there was.

[kt315]

oldie matter so giving a link in a help http://www.geotech1.com/forums/showt...ghlight=AD8055

[greylourie]

You also should look at overvoltage recovery. This is almost never spec'd so you have to test it yourself.

Does higher slew rate offer some hint as to better overvoltage recovery ? Aren't they almost the same thing ?

[daverave]

i found the LT 1028 has lots of ringing on the waveform so i guess its not a very good choice for a pulse detector front end....going to try so other mods later with audio and maybe some kind of meter.

[kt315]

Does higher slew rate offer some hint as to better overvoltage recovery ? Aren't they almost the same thing ?

am not able to answer on that - do not see any this relation note in ITMD book. seems you have to check that yourself in experiment.

[gef12]

I tried a few different makes of 5534 on the HH some were better than others ..the Phillips brand stood out...but the AD797 was best IMO

[treasurediver]

oldie matter so giving a link in a help http://www.geotech1.com/forums/showt...ghlight=AD8055

Attached a scope shot of a foil target at 1us, Preamp is AD8055

[treasurediver]

Sorry, the picture was a bit large.

Blue trace =No target
Red trace = foil target

Setting: 1us/div

[6666]

I tried a few different makes of 5534 on the HH some were better than others ..the Phillips brand stood out...but the AD797 was best IMO

In what way were the Phillips brand better performing ?
Signetics seem to have taken over Philips, did you try any with the Signetics brand ?

I've just bought a couple with the Phillips brand stamped on them.

[daverave]

why did you find the AD797 the best ???