Original question:
Hi Jason,
OPA129 is going to be obsolete soon.
In terms of noise performance, OPA145 has better input voltage noise specification than OPA129 at 10kHz BW. OPA145 (GBP=5.5MHz) has higher BW than OPA129 (Unity GBW=1MHz), which both part are comparable. The input current noise density are so small on both parts, though OPA129 is slightly lower than OPA145. However, the input current noise error contribution is insignificantly when they are compared to input voltage noise figures in JFET or CMOS input amplifiers (apple to apple comparisons using the same circuit configurations).
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Here is the data:
For OPA145, the input voltage noise density is approx. 7 nV/sqrt(Hz); the input current noise density should be approx. at 0.8 fA/sqrt(Hz), similar to 1kHz data.
For OPA129, the input voltage noise density is approx. 15nV/sqrt(Hz); the input current noise density should be approx. at 0.1fA/sqrt(Hz) at 10kHz.
Best,
Raymond
Hi Jason,
the noise of OPA145 is modelled by the OPA145 Spice model. Have a look at the TINA-TI reference design. This allows you to simulate the noise of your TIA:
If you need futher help, you can post the schematic of your TIA here.
Kai
