Other Parts Discussed in Thread: OPA1612, OPA1637,
Hello Mr or Mrs.
I designed I/V converter and MFB filter with Fully Differential Amplifier(FDA) for output of DAC(AK4499exeq)
I would like to verify the design and have some questions
1. In the data sheet of AK4499EXEQ(it is not freely download website), They are using two OPA1612 for I/V conversion each channel.
I think FDA amplifier would be better for performance... thus I plan to replace OPA163x(OPA1633 or OPA1637)
Is it possible to replace OPA1612 to FDA(OPA163x) and is it worthy?
The output of each OPAMP goes to IOUTLN and IOUTLP through Rfb, not opamp input(OPINLN) side.
In the datasheet, IOUTxx pin connected to OPINxx 30ohm.
2. I used OPA1637 for I/V conversion, and OPA1633 is used for MFB LPF because OPA1637 has very low "input current noise" and OPA1633 has very low "input voltage nose".
Do you think it is valid(resonable) assumption? ^^; I am not expert with circuit design.
3. I set the IS1 and IS2 set to zero in the TINA simulation because the 'Center Current' is written 0 mA in the AK4499EX datasheet.
Is it correct? The reason why I ask you this is when I increase IS1 and IS2, I/V simulation with OPA1637 is not processed in TINA but OPA1633 works. (IS1 and IS2 = 22.72mA)
22.72mA is came from 2.5V and internal impedance is 110ohm so... 2.5/110 = 0.02272 (I think it is stupid calculation..LOL)
I attached my TINA TSC file and datasheet of AK4499EX.
Could you please advise for me?
Thank you!akm.TSCak4499exeq-en-datasheet-myakm.pdf