Unanswered Questions
1,049 questions with no upvoted or accepted answers
5
votes
0
answers
101
views
Circuit with resistance equal to input resistance
I want to use a digital potentiometer, however, the digital potentiometer has a power limit, which means I can't apply the voltage for my application.
I am looking for a circuit which functions as an &...
- 9,270
5
votes
0
answers
1k
views
What is the upper frequency limit for an op-amp integrator?
I'm designing a circuit to process a di/dt signal. As the input is the differential of the measured current, I have to integrate the voltage to provide a representation of the current. The duration of ...
Null♦
- 7,623
5
votes
0
answers
870
views
PIN Photodiode gamma detection amplifier circuit - rectangular wave output
I've been working on a project recently, where I need to build a device which detects gamma radiation and can be used for gamma spectroscopy. I've done some research and found many interesting ways of ...
- 53
4
votes
0
answers
108
views
How to interpret this depiction of an op-amp circuit?
I haven't used/seen this type of op-amp depiction before, so I'm having trouble understanding it. The research paper (linked below) says that this is an AD844AN chip, but even after looking through ...
- 17.9k
4
votes
1
answer
140
views
Current source circuit components
I want to make a constant current driver for a laser diode (500 mA max.) based on the circuit shown below:
Here is my version:
In my case D2 and D3 represent the laser diode. There is a NC relay and ...
- 11.6k
4
votes
0
answers
374
views
Ultra-fast driver circuit for low-power LED
The goal is to drive a low power LED at a very high frequency, with pulses of ~10-100ns width in order to produce a very narrow burst of light. The pulses do not need to be closely packed together, ...
- 41
4
votes
0
answers
144
views
Nodal Analysis of an Inverting Operational Amplifier
I am trying to derive the closed-loop gain of a basic Inverting Op-Amp circuit using nodal analysis and the model that includes its non-ideal parameters. The equation I derived is incorrect, and it's ...
- 91
4
votes
0
answers
203
views
Fixing overshoot in current regulation of AC electronic load
My AC electronic load (previous question here) shall have a constant-current mode. It is being simulated in LTspice.
@devnull helped design the circuit for AC loads, but for simplicity's sake in the ...
- 8,567
4
votes
1
answer
121
views
Dual supply op-amp, 0V on input yet small voltage on the out
I've been working on a constant current source design and have come up with the schematic below (heavily inspired from the LTC6082 datasheet), however, there is a small issue. When my input voltage is ...
- 8,567
4
votes
0
answers
106
views
Audio amp IC: how does this output stage work?
I'm looking at an audio amplifier integrated circuit and the output stage seems a bit unusual. Has anyone seen this style of output stage, and does it have a name? And can anyone fill in the details ...
- 2,884
4
votes
0
answers
1k
views
Complete Noise Analysis: to find the minimum detectable signal of a TIA
Problem Statement:
my aim is to digitalize a 10ns narrow pulse coming from a photo diode with current ranging from 10nA-70mA, as its impossible to cover this dynamic range of >60dB using a single TIA ...
CommunityBot
- 1
4
votes
0
answers
1k
views
Deriving PI controller transfer function when input is reversed
I'm developing the compensator for the linear DC Bench Power Supply I'm
designing.
As I've come to deriving the transfer function for the op amp-based
compensator, I realize I've been depending on a ...
CommunityBot
- 1
4
votes
0
answers
2k
views
100kHz active filter design
I am designing a basic 100kHz active bandpass filter using opamps (LF353). I am only interested in receiving the 100kHz frequency (might drift a few kHz) from my input signal. I have used a basic ...
4
votes
1
answer
141
views
Output voltage not stable - What is compensation with respect to DC-DC (buck converter)?
EDITS:
Input voltage range: 24V to 48V.
Changing the load current from 0.38A to 1.018A increases the mean output voltage from 12.779V to 13.26V. The supply should be producing 12.5V.
I'm using this ...
- 324
3
votes
0
answers
66
views
Whats the relation between RC time constant and the GBWP of an opamp?
If I'm not wrong, an opamp circuit's feedback resistor and capacitor dictates the response time of it. So in case we have the control over Rf and Cf we can set the response time.
But in that case, ...
- 12.2k