Part Number: LMH32404
Other Parts Discussed in Thread: LMH6629, OPA855, LMH32401
Hello TI
We are currently using multiple units of the LMH32404 in our design.
This is working fine, since the bandwidth that we actually require is 125MHz and equivalent input capacitance is pretty low. Photodiode itself is well under about 700pF and PCB traces are quite short.
However, our new design calls for increasing BW to about 400MHz. Along with that, the geometry of our photodiode sensor and substrate may change, causing an increase in Cin at the TIA. This is due to both longer trace length and higher dielectric constant of the material. I predict Cin (PD + parastics) to reach about 3pF.
Could you recommend any other way of implementing a TIA that would give an equivalent output noise density to our first design (LMH32404) but higher BW along with the larger Cin?
I thought maybe of using a shunt R to ground followed by a non-inverting LMH6629, but it is hard to get the high gain and high BW simultaneously from such an arrangement.
Any ideas will be appreciated.
