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52 views

Designing a 4053 IC robotic control circuit for interfacing with Sabertooth motor controller?

I am designing a control circuit for a robot and was recommended to use a 4053 IC to achieve analogue multiplexing. PROBLEM The Sabertooth 2x60 motor controller I am using is running in analog ...
5
votes
3answers
864 views

Non-inverting amplifier ; Single supply ; Bipolar input

I am working on the non-inverting amplifier using a single supply, which can amplify bipolar input signal. Non-inverting amplifier is working fine without any issues, only the negative portion of the ...
0
votes
1answer
34 views

Direct coupling Biasing of Two stage amp

General question. I see a lot of two stage amplifiers with a diff pair input and a cs second stage. In IC design these two stages are always directly coupled ie. the dc bias of the second stage is fed ...
1
vote
1answer
53 views

Laser audio transmitter - need substitutes

I'm building a laser audio transmitter that uses amplitude modulation to transmit audio via a 5mW laser beam. The transmitter uses a microphone, an operational amplifier (to modulate the signal if I'...
-2
votes
0answers
38 views

Op-Amp comparator or amplifier? capacitor in non inverting input

If someone can clarify to me what is the action of this OP amp, is it comparator or amplifier? I know when there is negative feedback the op-amp is an amplifier, but here has a capacitor, what is it ...
5
votes
2answers
2k views

Rail-to-rail op-amp only reaches 90% of VCC, works sometimes, not everytime

I have created a simple data acquisition module for measuring 5V signals. There are 18 analog inputs on this board, all of which are a copy of the schematic below. Each input has an op-amp (MCP604) ...
2
votes
2answers
115 views

Operational Amplifier Problem

I'm trying to find $$\frac{V2}{V1}$$ as a function of x. I found this circuit but noone gave good explanation. I think I understand the way this potentiometer works, but I just can't work out the ...
3
votes
2answers
52 views

Help understanding current noise

My understanding of current noise is that you multiply the current noise by the input impedance and that gives you the noise level in volts. I’m looking at the LMC6001 opamp and it states in the ...
6
votes
2answers
400 views

What does the wifi amplifier exactly amplify?

The question is not exactly about the wifi, but on how does this operate in full duplex, in principle? As an practical example, lets take some commercial amplifier. As we can see from the picture, it ...
-1
votes
1answer
46 views

Lower noise in biased op amp

I have a circuit similar to this. I’m trying to lower my noise under 60 Hz. Using pspice I keep finding that I need a very large resistor for R5, like 50 gigs but in practice this is not giving me the ...
1
vote
0answers
49 views

What component is best for a voltage follower amp (specs given in question)?

I am wanting an op amp that can act as a voltage follower. Essentially the project is speed control of a motor and since PWM is being used, the following circuit was going to be implemented: ...
0
votes
1answer
58 views

40kHz Ultrasonic transducer - datasheet gives capacitive load at 1kHz what is it at 40kHz?

A hopefully simple question, the datasheet for a 25kHz Ultrasonic transducer gives the capacitance load at 1kHz what is it at 25kHz? I've been calculating the current using I = fCVpp where f is ...
2
votes
1answer
56 views

How to amplify a signal for piezo transducer from 1 Vpp to 200 Vpp at 400 kHz and 500 pF load

I'm a researcher working with phased ultrasonic transducer arrays. I need to amplify a sine wave at 400 kHz and 1 Vpp to 200 Vpp. It has a capacitive load of 500 pF. I'm little ...
0
votes
1answer
57 views

Compensated vs uncompensated Op Amps [closed]

What are the advantages/disadvantages of compensated and uncompensated op amps? Thank you in advance.
1
vote
3answers
85 views

Difference between two integrator circuits

What is the difference between the two integrator circuits? They are used in an amplifier with feedback. There's heaps of information online about the one on the right but not so much about the one on ...
3
votes
2answers
166 views

Gain of Non-Inverting Amplifier Does Not vary with Resistor Values

I am trying to build a non-inverting amplifier using a LM7171 op amp, and I am implementing it with potentiometers as Rf and R2 so that I can smoothly control the gain of the amplifier (and easily ...
-1
votes
1answer
72 views

Cascading Op Amps for Phototransistor Output Conditioning

I am working on a project in which I am using an IR phototransistor to detect changing low levels of light. Currently with very high load resistance I can get a reading of 40-60 mV but I would like to ...
4
votes
2answers
1k views

Single supply non-inverting amplifier using op amp

I'm working on building a distortion guitar effect pedal for an analog electronics class I'm taking. I am struggling with building an amplifying circuit using an op amp (we just began learning about ...
1
vote
1answer
65 views

Input impedance of differential amplifier

Can someone please explain to me, how I should look at the input impedance of the opamps, seen through the voltage \$V_1 V_2\$? I have two questions on the differential amplifier: Why doesn't the ...
2
votes
3answers
137 views

Potentiostat Drift

Firstly - First post so let me know if I have done anything wrong. Okay, so I am tying to get this biased potentiostat to work. I have attached the circuit below. I am using the following sensor: ...
1
vote
1answer
63 views

Multiple feedback single supply

I've been trying to get a multiple feedback lowpass filter to work. With this schematic. The filter works in the simulation but when i try to build it, it gives no output. The op amp used to build ...
2
votes
2answers
260 views

Voltage output waveform of a differentiating amplifier

I have the following picture of the input and output voltage waveforms from a differentiating amplifier as shown below: And the schematic is as shown below: My teacher claimed that these waveforms ...
1
vote
1answer
71 views

Amplifying Sinusoid From Microcontroller to ~40V 3-5A

I’m investigating transient switch arcing that occurs in a 3 phase switching unit. I am planning on generating the phase signals with an STM32F4 using DAC and DMA with timing separation for the phase ...
0
votes
1answer
50 views

Volume Control for Mixer Circuit using DAC Refence

I am mixing two stereo audio signals together and would like to control the output volume using the (0-3.3v) DAC on my microcontroller. I'm wondering if there is a simple modification I can do to this ...
6
votes
5answers
2k views

Circuit to “zoom in” on mV fluctuations of a DC signal?

I have a signal that is roughly 0.2V + noise fluctuations of order 0.1-2 mV. Ideally I want to amplify this signal such that the mV fluctuations become about 1V. In other words I want to amplify the ...
0
votes
2answers
70 views

Accelerometer Sensor Output Impedance

I am looking into purchasing a TE 810M1 Accelerometer and had a question regarding the resistor's value for amplifying the sensors output. Here is a photo of the sensors electrical properties: The ...
1
vote
2answers
70 views

Op amp diode clipping

I am creating the following diode clipping circuit: The input signal, Vin, offset is removed and the signal is amplified using an op-amp. Then there are two diodes designed to clip the signal to +/- ...
0
votes
0answers
38 views

how to power up a subtractor using a window comparator?

I'm making a circuit that will detect whether a voltage(V1)is in between the range 1-2 V. If so I want to switch ON a subtractor and output V1 - 1 V. I initially thought of connecting the output of ...
5
votes
3answers
1k views

OP Amp not amplifying audio signal

Hi, part of my project requires me to amplify an audio signal coming from an electret condenser microphone which outputs an average of 10mVpp to approximately 2.5Vpp. I Used two cascaded non-inverting ...
0
votes
4answers
83 views

Op Amp: signal measurement that is below its common mode input range

I was wondering, how is possible to use an op amp, which its common mode input voltage is (V-) + 0.2V to (V+) - 0.2V to measure signals as low as 10mV for example? I'm looking for an ...
4
votes
2answers
233 views

DC input on op amp integrator

I am trying to integrate a DC tension with a classic op amp integrator. The problem is : when I simulate my circuit on LT Spice, the output will always be equal to the VEE tension of the op amp ...
-1
votes
1answer
105 views

How can Vo = A(V+ - V-), if V+=V-=0? [duplicate]

We’re considering an ideal opamp here; so does that mean that Vo is infinity ♾ * 0 (A * (V+ - V-))? Thanks!
0
votes
2answers
66 views

Amplifier and Low Pass filter not responding after few minutes of correct output?

I am trying to design an amplifier and low pass filter circuit for a piezo sensor. My frequency of interest is .3 Hz to 5 Hz, for first stage I have used charge amplifier and the subsequent 3 stages ...
3
votes
2answers
1k views

Current measurement op-amp calculation

I am trying to measure the current using sense resistor method. Low Side Current Sensing method: I am using shunt resistor in the low side, there will be a voltage drop across the resistor. Since ...
1
vote
0answers
88 views

Voltage controlled amplitude problem - JFET circuit

I work on a function generator project. It generates waveforms such as sine, triangle, rectangle with PWM regulation, saw. I would like to digitally adjust the signal output amplitude. Input signals ...
1
vote
0answers
55 views

Amplification problem

I am using an instrumentation amplifier AD620ANalong with another amplifier TL084CN in series. Both have gains of 100 which essential for me since the input is in microvolt range. The frequency is 87 ...
3
votes
3answers
161 views

0-2v to 0-10v amplifier

tl;dr: I want to understand op-amps better! How do I choose the magnitude of resistors? 1k, 10k, 100k, etc.. I made a schematic to play with an In-amp to create a gain of 5. What other ...
0
votes
3answers
105 views

Why my HB100's amplifying circuit can't generate more than a signal of 200 Hz?

I want to amplify the HB100's IF signal with the circuit shown below, but when I test my circuit I can't read more than 200 Hz, maximum 300 Hz. The circuit works with the OPA2365 integrated circuit at ...
2
votes
1answer
223 views

Generating a constant-amplitude triangle wave from a square wave

I have designed a circuit that can generate sawtooth and arbitrary duty cycle pulse waves controlled by some variable DC current source \$I_0\$, giving a frequency proportional to this current. The ...
0
votes
0answers
25 views

Voltage conversion between multiple orders [duplicate]

I have this circuit in which I want to convert the input voltage of micro order to volt. The circuit image has been posted. I have figured out the bandpass filter ( basically everything after the big ...
2
votes
0answers
96 views

Why resistor is used at the output of OPAMP?

I'm reading this note and in Figure 1(page 1), there are two resistors R5 and R10 whose use I don't understand. From my understanding, R5 would cause offset due the input bias current and R10 would ...
1
vote
1answer
72 views

Op Amp Input Offset Voltage vs Common Mode Voltage

I would like to use an op amp AD8618 for a design, and need the input offset voltage to be low. For this op amp it seems fine with maximum of 65uV, but looking at the charts on page 6 etc, it seems to ...
0
votes
2answers
67 views

Why the don't the theoretical and practical output of comparator match for small input?

I have been using TL084cn IC which is basically an amplifier IC. I was giving the input to it of amplitude around 450mv. This IC is capable of providing a slew rate of 13. The Vcc given to it ...
1
vote
0answers
31 views

Gain bandwidth product of amplifier in a DC scenario

I think I have a simple (but still to me confusing) question regarding the gain bandwidth product (GBP) of an instrumentation amplifier: Datasheet (AD8237) I have sensors that change their output ...
0
votes
1answer
81 views

Why is one of the transistors in ROM sense amplifier twice the width of the one opposite of him?

The picture is of Sense Amp design of ROM component in which a 'dummy' bit line is used to imitate the current so that the proper information can be derived from the memory cell by comparing the ...
3
votes
1answer
101 views

Connecting bandpass filter to comparator generating excess noise

I have a band pass filter with a center frequency of 100kHz, a bandwidth of 10kHz, and a gain close to 1. Input signal is 100mV-150mV peak to peak with frequencies varying from 80kHz to 120kHz. I am ...
0
votes
0answers
126 views

Non-Inverting Single Supply comparator hysteresis is too wide

I am trying to convert an input sine wave to a square wave. The sine wave is centered at 2.5V and has an amplitude of 200mV, with a frequency of 100kHz. I am looking for a hysteresis of 100mV ...
1
vote
1answer
68 views

Common Mode and differential Mode gain of this Cmos diff Amp inverter

This is one of questions our prof gave to students in recent years and im preparing myself for this exam. What is Common Mode and differential Mode gain of this Cmos diff Amp inverter? i understand ...
1
vote
2answers
86 views

High voltage gain block

Schematic 1 shows a discrete operational amplifier which is used as a gain block to make up to 450V out of 12V. Q3 and Q4 are used to generate a current which is used by the current mirror. This is ...
1
vote
1answer
45 views

DC Gain too low at higher voltages

I am having an issue with DC gain for a non-inverting op amp circuit. All I am trying to do is double the voltage from two DAC outputs (DAC range is 0 to 5V and I want it to be ~0V to 10V). The DAC ...