Part Number: TLV320ADC5140 Other Parts Discussed in Thread: LMP7731 , OPA1632 , LM4562 ,
We currently utilize a Cirrus Logic ADC (stereo, I2S master) in our main product but were researching alternatives; our plan was originally to switch to ESS but we've…
Clemens,
Even though LMP7731 (GBW of 22MHz) has lower input voltage noise spectral density than comparable speed OPA320 (GBW of 20MHz), being a bipolar input op amp LMP7731 typical input current noise spectral density is more than three-orders of magnitude…
Other Parts Discussed in Thread: LMP7731 I want to know a measurement circuit at the 1khz of Voltage Noise Density.
for 2.9nV/rtHz (f=1Khz)
Because I cannot measure 1Khz by a measurement circuit of figure 2
Thanks
Hello again Bernd,
I did some investigating on the LMH6642 (and the LMP7731). The LMH6642 has a higher bias current than the LMP7731 by an order of magnitude. The uA bias current of the LMH6642 enables the performance difference you are seeing at relatively…
Hi Thomas,
thank you for your suggest.
i am asking to learn, LMP7731, why I couldn't understand better than opa365? Please tell me where I made a mistake
yes, LMP7731 has low voltage noise density than OPA365 but its current noise density is a little…
Hello kai,
actually i know the noises are added in rms but i couldn't think of here.
thank you so much for showing me wrong.
But the circuits with LMP7731 don't have any filter and not differential
Hello Ravi,
The OPA378 uses a chopper op amp design. Three things that assure the best performance from a chopper op amp are low source impedance, matched impedance paths for each of the inputs, and low to moderate voltage gain. Observing those points…
Hi Gerd
Thank you for your suggestion. As you pointed out there are other factors beside pumping current to get lower 1/f. Geometry being one of the factors, it can be prohibitive for some devices depending on target applications, markets and of course…