Timeline for Bootstrapped Transimpedance Amplifier (TIA) - High Frequency Instability
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 30, 2018 at 7:24 | vote | accept | J-Pease | ||
| May 30, 2018 at 5:47 | comment | added | Sven B | Yes, you're right, my bad. I used 1pF=1e-15F, but that is obviously incorrect. I should refrain from posting when I just woke up ;-) | |
| May 30, 2018 at 5:42 | comment | added | J-Pease | Hi Sven, I believe you've made an error in your calculation, that will give a bandwidth of 50kHz not 50MHz. | |
| May 30, 2018 at 4:53 | comment | added | Sven B | I read that you're targeting 50MHz. This is approx. \$BW\approx\frac{1}{2\pi R_f C_f} \$ if your open loop gain is high enough. So yours is around 32GHz. You can increase \$C_f\$ until 636pF for a BW of 50MHz. | |
| May 29, 2018 at 23:56 | history | edited | J-Pease | CC BY-SA 4.0 |
added 147 characters in body
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| May 29, 2018 at 23:35 | comment | added | J-Pease | Thanks for your suggestion Sven, I haven't tried increasing the feedback capacitor past 1pF. Having said that based on some of my previous work with the standard TIA configurations (i.e. non bootstrapped) with the same photodiode and op-amp the noise peaks tend to be at ~10MHz if the amplifier is not properly compensated. I could try increasing Cf further to examine the effect on the 50MHz peak but I fear that this will only cut into my bandwidth further and offset the potential improvements of the bootstrapped configuration. | |
| May 29, 2018 at 12:18 | answer | added | user16324 | timeline score: 1 | |
| May 29, 2018 at 9:49 | answer | added | Andy aka | timeline score: 1 | |
| May 29, 2018 at 9:04 | comment | added | Sven B | Have you tried increasing Cf to improve stability? Stability is very dependent on the total capacitance to ground at the input, so if your actual input capacitance is higher than in simulations (eg. due to the bootstrap circuit not working perfectly, layout issues, etc.) it could lead to instability. | |
| May 29, 2018 at 7:06 | history | asked | J-Pease | CC BY-SA 4.0 |