Best opamp for I/V conversion? (DAC)

[6h5c]

That is the uncompensated GBW. The more you compensate, the smaller GBW will be. GBW can therefore not be 60MHz compensated.
It will be about 10MHz with 22pF compensation and 100pF load. See datasheet.
100pF is not an unpractical value if you load the opamp with a filter stage or interconnect at the output.

Regards,

Ray

[Nazar_lv]

That is the uncompensated GBW. The more you compensate, the smaller GBW will be. GBW can therefore not be 60MHz compensated.

ofcoarse, with miller compensation, but why to do that the best compensation that do not give disadvantages is RC input compensation.
5534 from TI is de fakto unity gain stable (TI has another layout), 5534 from others(NJM,TDA,SSM) will oscillate with unity gain&small output capacitor

It will be about 10MHz with 22pF compensation and 100pF load. See datasheet.

it is IDIOTIC schematic simply for example

100pF is not an unpractical value if you load the opamp with a filter stage or interconnect at the output.

for ANY opamp any capacity at the output(&input) must be isolated (it is not difficult) or properly compensated

my regards,
Nazar

[6h5c]

RC input compensation still reduces the effective practical bandwidth that we can use, that's the point of compensation, right?

Ray

[Nazar_lv]

RC input compensation do not reduce gain, slew...

[Bassivus]

Originally Posted by 6h5c

Your idea is not uncommon, at least not for me or in the CD63/67 mods thread

I've been experimenting with lots of opamps over the last few years. My favorite combo is the AD8610 with AD8510 for my CD67-OSE at the moment. For a TDA1541 DAC, the AD797 is a nice one indeed, but I also like OPA211 and AD8597.

Regards,

Ray

To get back on topic! If we are chasing high slew rate for I/V opamp AD844 with its 2000 V/μs seems to be one of the best here or I'm missing something?

[jcx]

Originally Posted by Bassivus

To get back on topic! If we are chasing high slew rate for I/V opamp AD844 with its 2000 V/μs seems to be one of the best here or I'm missing something?

that there's no obvious reason to chase high V slew rate?

except as a proxy for increased linear input range - but why not 1st design the circuit for low input V error?

DAC I/V for reproducing audio doesn't need to move the output faster than the filtered audio frequency output signal's rate

there's no need to reproduce the step/switching glitches - they should be flitered out as early as possible

high current/low open loop Z output stage would be a better way of soaking up the glitches thru the feedback C

[6h5c]

Originally Posted by jcx

there's no need to reproduce the step/switching glitches - they should be flitered out as early as possible

That's right, they should be filtered by, well... a filter, but not limited by the opamp's slew. That will most likely create intermodulation distortion.

Ray

[Nazar_lv]

there's no need to reproduce the step/switching glitches - they should be flitered out as early as possible
high current/low open loop Z output stage would be a better way of soaking up the glitches thru the feedback C

We cant filter glitch, but we don’t have to do that, we only can reduce slew rate of glitch impulse (energy would be the same but with low-frequency spectrum) so they do not overload opamp input stage, then we can use highly linear low frequency opamp (4898, 1468, 49710 etc).
Use of video opamp in I/U is fight with the consequence rather than cause
regards,
Nazar

[6h5c]

I plea for a gentle 1st order passive filter before the signal enters the opamp.

Ray

[tiefbassuebertr]

Are there new experiences?
In the meantime was launched various new OP-AMP IC's from TI/Burr Brown, Analog Devices and National Semiconductor.