TechnoGilles
New Member
Hi all,
I'm currently designing a balanced mic preamp for a project. My two major constraints are
1) I work with 0-5VDC single supply.
2) I want phantom power (48VDC)
From the datasheets I've read, and from what I found on the Web, here is what I have so far.
Any comments, suggestions, about my design ?
I especially want to validate the following:
1) I plan on using the AD623 Inst. op-amp. Good ? Bad ? Ok ?
2) As shown in the diagram, the total gain of my design can vary from +20dB to +60dB. Is that enough ? Should I get it all from the inst. op-amp and forget about the extra gain stages of my codec ?
3) Is my DC coupling from 48V to 0V to 2.5V using 47uF caps ok ? Should I look into transformer coupling instead ?
4) Are the diode bridge and limiting 10Ω resistors ok to protect the op-amp from the 48V phantom power ?
Thanks a lot !
Any comment will be appreciated !
I'm currently designing a balanced mic preamp for a project. My two major constraints are
1) I work with 0-5VDC single supply.
2) I want phantom power (48VDC)
From the datasheets I've read, and from what I found on the Web, here is what I have so far.
Any comments, suggestions, about my design ?
I especially want to validate the following:
1) I plan on using the AD623 Inst. op-amp. Good ? Bad ? Ok ?
2) As shown in the diagram, the total gain of my design can vary from +20dB to +60dB. Is that enough ? Should I get it all from the inst. op-amp and forget about the extra gain stages of my codec ?
3) Is my DC coupling from 48V to 0V to 2.5V using 47uF caps ok ? Should I look into transformer coupling instead ?
4) Are the diode bridge and limiting 10Ω resistors ok to protect the op-amp from the 48V phantom power ?
Thanks a lot !
Any comment will be appreciated !