Part Number: JFE150EVM Other Parts Discussed in Thread: OPA202 , , JFE150 Hi, I note in the JFE150EVM there's an LC on the supply input, with a corner around 1 kHz or so. I'm wondering with 60 dB of gain how sensitive the Figure 4-1 circuit in the JFE150…
Hi Nir,
We have an EVM for the OPA928 that can be found here:
https://www.ti.com/tool/OPA928EVM
I have several app notes on circuits that use discrete JFET devices that you may consider. I have an EVM that goes along with both the JFE150 and JFE2140…
Hi Dimitri,
The current noise density is frequency dependent but remains flat in the broadband region as shown below. The noise can be measured using the JFE150 or JFE2140 EVMs that I designed. I wrote two app notes that cover the operation of each…
Part Number: OPA1656 Other Parts Discussed in Thread: JFE2140 , , OPA202 , INA849 , JFE150EVM , JFE2140EVM , JFE150 , OPA145 Hi,
I want to know the proper configuration to connect a low-frequency antenna (L = 12mH @ Rdc = 7.5Ω @ Cp = ~ 60pF) to an opa1656…
Hey Camille,
You may consider adding an LC filter similar to what I did on my JFE150EVM. There is a much more detailed explanation in the video link below on power supply filtering.
https://www.ti.com/video/3872230260001
The inductor value I used…
Hi Yang,
The capacitor around the OPA202 isn't currently doing anything because the corner frequency is in the 1/beta curve and comes after the OPA202 aol corner created by the miller cap. I put it in the app note and the EVM for the circuit as a placeholder…
Hi Jeremie,
I am the engineer who wrote the app note. I will be out of office for the next week and will be returning on July 22nd at which point I can address some of these questions. Most of the questions are addressed in the Grey and Meyer text for…
Hi Santosh,
One thing I noticed in your calculations is that VCC is 3V. Is that correct? Do you know what the minimum drain to source bias voltage is for the JFET internal to the microphone? As an example, you can see below that there are two modes…
Hey Jeremie,
Let me know what you think of this design (Tina attached at the bottom). I put in the OPA354 that has much lower Ib in the pA range. It can be any similar amplifier but this is just an example.
You can see below that I have the JFE150…
Hey Andrew,
The OPA1642 has much lower current noise and better 1/f noise than the OPA1656. For high source impedance sensors such as a phono cartridge lower current noise is better. The current noise paired with high source impedance translates into…
