Part Number: OPA842 Other Parts Discussed in Thread: OPA615 , Hi,
I'm trying to build a peak detector used for square wave @10MHz and the amplitude as low as 100mVpp. I followed the circuit in the OPA615 datasheet but run into the following issues: …
Part Number: OPA842 The attached circuit has been verified on a ATE (VLCT) board. It was copied to a new ATE (V93K) board but is oscillating. Is there a spice model for this part so I can use Tina to run some simulation?
Thanks,
Cindy
Other Parts Discussed in Thread: OPA842 I am using the OPA842 in a traditional trans-impedance configuration with a BF862 as input buffer (included in the feedback-loop). Gain is 20dB up to around 10MHz.
I have measured IP3 on this amplifier with f1:1…
Hi Matthew,
Couple of ideas:
1. Post Amplifier with variable gain:
I found this older E2E post which has some suggestion on a post amplifier with adjustable gain settings, I thought I share with you:
http://e2e.ti.com/support/amplifiers/high_speed_amplifiers…
Me thinks the circuit from figure 48 is crap
I would do it this way:
https://e2e.ti.com/support/amplifiers/f/amplifiers-forum/763240/opa842-non-inverting-resistor-calculation
Kai
I might want to increase the gain by an order of magnitude. Can you give me an accurate Cf calculation (formula) for 1pf and 10 meghahertz input signal? The Cf value is so low, that's why I want to use the alternative configuration. I will try to…
Other Parts Discussed in Thread: LOG112 , LOG101 , OPA820 , VCA821 , OPA842 I'm looking for an amplifier which satisfy the following specs :
1) Output current of detector will vary between 10nA to 150mA
2) Minimum Pulse width (ON Time) will be 5ns.
3)Pulse…
did you try on real board ? well i am trying to use OPA842 now, what do you think of making two stages amplifier the first with unity gain stable opamp Opa842 and the second one with the opa847 ?
Thank you, i will be waiting for your test results.
…
Your 1st circuit with the opamp circuit - that is positive feedback. Also, I am unclear how you expect the circuit to work.
Your 2nd circuit is open-loop...may not be the most optimum stable solution.
Here is a potential closed-loop opamp solution. For…
