Other Parts Discussed in Thread: OPA637 , TINA-TI , OPA141 Hi,
We have a preamplifier design using the OPA637AU and are experiencing high noise levels (~30nV/rtHz, rti) apparently due to current noise. The input source presents approximately 330pF//10M Ohms…
Alexey
I cannot say for sure why the OPA627/637 cannot be found on the parametric search. It may be that given their age/price they are being de-emphasized. Be assured it is very rare for a part to not be included in the parametric search.
Unlike the…
I cannot find a direct replacement for the AD844 for its BW and Slew-rate combination. The THS3091 has greater BW and slew-rate. The THS3120 has slightly larger BW but smaller slew-rate than the AD844.
The OPA637 will be a good replacement for the AD845…
By the way, the schematic called for OPA627, but the build I find in my hand has OPA637. I've been studying further and have figured some things out, but not yet all. It appears the OPA627 has a 75 degree phase margin, but the OPA637 has little or…
Hi Helmut,
When computing SNR over such a low LPF frequency (4.02Hz), keep in mind that you are in the 1/f noise region of the OPA637. Therefore, depending on the Noise Analysis start frequency (where you've used 1Hz), you'd get a different SNR result…
Other Parts Discussed in Thread: OPA637 , OPA657 Hi guys, I am designing a transimpedance amplifier with current source from an avalanche photodiode model from hamamatsu with capacitance of 15pF and the detector will detect the input signal from (very far…
Thanks Bruce,
I made a mistake, it was OPA637 that I want to use, not 635. OPA 637 has a very low input bias current, and very low noise.
Actually I need a10^9 transimpedance gain with the desire bandwidth 4KHz(@-3dB), and very low noise. Ideally inverting…
Other Parts Discussed in Thread: LOG114 , TINA-TI , REF5025 , DAC9881 , LF356 , OPA381 , OPA627 , OPA637 , OPA703 Hi,
I am doing a project on absorbance measurement using photodiode from Hamamatsu S1223 . I need to design the transimpednce amplifier for the photodiode…