Questions tagged [analog]
Analog circuits have a range of voltages, rather than just two as in digital logic.
2,004
questions
2
votes
2answers
84 views
How is circuit topology chosen in analog designs?
Suppose I'm an experienced analog designer, e.g., RF, power electronics, ADC.
How does choosing a circuit topology fit into the overall workflow for a typical work assignment? I imagine my manager ...
1
vote
1answer
30 views
Does MAX3665 amplifier have a minimum operating frequency?
I am using the MAX3665 in a design. The amplifier has an IR Photodiode at the input and is failing to detect any signals. My signal generator outputs a maximum of MHz square waves and MHz sine waves.
...
1
vote
2answers
70 views
How should I start an electronics project? [on hold]
Background
I have limited exposure to practical and real-life electronics (particularly in the analog world). I haven't made something all by myself from the ground. So to remedy this, I want to make ...
0
votes
0answers
19 views
How to characterize a lower node transistor?
I am a fresh college graduate and have recently started working as analog design engineer. I am working on 22nm FDSOI technology, And characterizing this device has been trouble for me. The device is ...
0
votes
3answers
59 views
90 degree phase shift
I need to use a clock signal of 50% duty cycle of 2.5MHZ and I should make a circuit which phase shifts it to 90 degrees.
So now I have four signals...( ** PHASE SHIFT WITH RESPECTIVE CLOCK SIGNAL)
...
0
votes
2answers
36 views
555 PWM motor driver controlled by external analog signal
I used the below 555 timer PWM circuit to control the speed of a dc motor, and it works like a charm :)
now i have a requirement to change the PWM speed externally from another module, that module ...
0
votes
1answer
32 views
ADC input with Low pass RC filter
I’m trying to implement 8 bit ADC in FPGA. FPGA running at 100MHz clock.
PWM signal is given to RC filter. Knowing that f=1/2piRC,
I have trouble with choosing the component's value. Is there any ...
1
vote
4answers
119 views
matched pair vs dual BJTs
Is there any practical difference between a matched pair of transistors and dual transistors in one package? Realistically, the latter are also two transistors from the same die, so they should be ...
1
vote
1answer
36 views
Quality Factor and Frequency Bandwidth in a matching network
it is known that the Quality Factor appears in the formulas for transformation of an impedance series bipole to a parallel one. A simple example is this one:
Now I have three questions:
1) I have ...
1
vote
1answer
52 views
PWM to analog voltage conversion for communication between two microcontrollers
I want to use this schematic for sending PWM signals from an STM32F0 Arm microcontroller to an ATtiny85. I want to convert the PWM signal to a proper analog voltage, so that the ATtiny analogRead() ...
0
votes
1answer
42 views
what does phase really mean?
I'm new to EE, and I am reading a text book which says:
Phase describes the position of the waveform relative to time 0.
The a quiz asks What is the phase shift for a sine wave with the maximum ...
1
vote
2answers
63 views
Laying out power electronics on analog signal board, practical advice
to keep this brief I am designing some audio circuitry and also need to design the power supply. The barrel jack in the schematic below sees 18VAC and I am converting that to +/-15V DC rails.
So to ...
0
votes
3answers
123 views
How to generate custom digital signals without microprocessors?
I'm in IT but I'd like to try some EE without any programming...
I'd like to make a circuit that outputs some custom digital signals. For example, an SOS signal:
...
1
vote
2answers
113 views
MOSFET as heating element for a RaspberryPi
I developed a PID autotuning algorithm that I want to test outside of a simulation environment. For this purpose, I got temperature sensors to send data to a RaspberryPi.
Now I need something to ...
0
votes
0answers
49 views
Single-ended analog signal to differential
I need to transmit 2 analog signals over a cable in a noisy environment.
How to transmit them as differential ?
Given that :
Each signal can be used to inject and receive current (< 130 kHz, &...
0
votes
1answer
12 views
Protection for power-off case with active input
My application is roughly depicted in the attached image.
I am sensing a Vin voltage, by dividing down with a resistive divider, then passing the signal through an opamp and an RC filter (not shown) ...
2
votes
1answer
106 views
How to transmit analog signals over cable?
In my current project, I need to transmit 4 analog signals (A1, A2, A3 and A4) on a cable from one PCB to another. I am working at 3 VDC and the distance between them is relatively short (< 30 cm).
...
0
votes
1answer
64 views
Quality Factor Formula
I read on many books this formula to calculate the quality factor of a series between a resistance and a reactive component (L and/or C):
Now let's consider the series between a resistance and a ...
0
votes
0answers
44 views
Safe and feasible way to multiplex CAN bus?
Is there a standard method or tool to connect more than one CAN bus to a CAN controller with single CAN interface? Each CAN bus would be directly connected to individual transceivers and then the Tx,...
0
votes
0answers
37 views
capacitor selection for charge pump
In one of my project i need 12v logic level (for programming controller) and my circuit is running on 5v. So, instead of using 12v supply i am thinking to use charge pump circuit because i just need ...
1
vote
1answer
52 views
Opamp input offset voltage when saturation
I wonder, how to affect the input offset voltage of inverting amplifier when it's output in saturation?
I'm changing gain with decreasing the value of R2. When the gain is greater than 5, output in ...
0
votes
0answers
33 views
How to make a solid state SPDT switch?
I'd like to make an analog SPDT switch along the same lines as FSA2259UMX or similar chips, but out of simple discrete components. This is partly for learning, and partly because I'm redesigning a ...
1
vote
1answer
53 views
Ground Plane Layout for Power Supply on PCB
I'm in the process of designing my first PCB. For the power supply, I have a 4.5V battery pack fed into a voltage regulator that outputs 3.3V. This section of the PCB and governing schematic are shown ...
0
votes
1answer
33 views
Mitigate TPS56* ecomode ripple effect under lighter loads
Following my question Powering up analog part of the video card (thanks everyone for their inputs and advices) I have chosen the devices, and even have drawn the circuit diagram of 12 V to 5 V power ...
4
votes
3answers
429 views
AD823 current sense
Refer the attached schematics.
Consider the details mentioned in it. I want to build the current sensing scheme using the part AD823 . enter link description here
I understand that offset correction ...
2
votes
1answer
75 views
When checking for continuity between two points on a PCB, how do I know it's not going through an inductor?
When trying to debug a non-working circuit on a PCB, it can be difficult to trace the circuit flow visually, as described in the answer to this excellent and related question:
How can I reverse ...
2
votes
1answer
41 views
Cascade of 555 timer with Control Voltage not triggering
Hi
I'm currently working on a cascade 555 circuit, both operating in the monostable mode. I also want to be able to control the pulse width with a voltage so am using applying 0-5v to the ctrl pin (...
1
vote
1answer
67 views
Mismatch on string of resistors for DC bus voltage sensing
In the picture below, you can see a string of 10 resistors used for DC bus voltage sensing. I think that the blue resistors (the original ones) are 400k/1W. The colors are: yellow, black, black, ...
3
votes
2answers
73 views
The Pin 1 Problem in Audio, Star and Mesh Ground, and Contradictory Grouding Practices in Audio and Digital Systems
I recently came across the concept of "Pin 1 Problem" known in the pro-audio electronics. It seems straightforward at first, but becomes confusing when it comes to grounding. Let me describe the ...
5
votes
2answers
3k views
Can someone identify this old round connector?
I am trying to develop something to control an old antenna rotator, and it has a connector like this one:
It does not seem to be a simple audio connector, but is more or less of the same size. What ...
1
vote
1answer
32 views
What is this “drive circuit” for CCD sensor referenced to?
I had a look at the TCD1304DG CCD sensor which I consider using in a project. The datasheet is pretty lucid, but I couldn't figure out what the following diagram is supposed to say:
Is this just a ...
1
vote
1answer
36 views
ADXL354 Power Sequencing Sources and LDO's
The ADXL354 with Analog Outputs include three power pins: Analog Power Source V1P8ANA, Digital Power Source V1P8DIG and Logic ...
1
vote
3answers
90 views
How to keep PWM from “contaminating” analog read values on my pcb
So I'm designing a PCB for a MIDI controller with a lot of slide potentiometers and push buttons. I'm also backlighting the pushbuttons with LEDs running on PWM and I'm worried that the PWM for the ...
0
votes
1answer
53 views
ECG / EEG Amplifier design tricks
First of all, sorry, I missed the links / images where I have found the solutions mentioned below (I hope, if you are familiar with this topic, you know them):
I have to design an ECG / EEG analog ...
0
votes
0answers
25 views
External Current Sourcing Sensor parallel to PNP BJT
I have Biased the transistor Q1 in active region as shown in the following diagram. I have Sensor which outputs 1-10ma and needs to be connected across parallel as per the following diagram.
the ...
1
vote
1answer
61 views
Window comparator diode direction
What happens if we reverse the configuration of diode in window comparator? Will it remain a window comparator?
0
votes
2answers
25 views
Splitting 0-10V Analog signal from 1 AO to two different set of Ventilators to regulate speed?
Is it possible to take 0-10V signal from analog output and split it in parallel to two different Analog inputs ..to regulate speed of two different sets of ventilators? Or do i need some special ...
8
votes
3answers
269 views
What are the calculations to do in practice to estimate beforehand the noise seen on the output of this op amp circuit?
I would like help with understanding something better, but am not trained in electronics so please bear with me!
I am trying to make a simple circuit to take a {-10V ... +10V} signal from a function ...
0
votes
1answer
27 views
Successive Detection Logarithmic Amplifier
let's consider this logarithmic Amplifier:
I do not understand why at the terminal LOG OUTPUT there is a current which is proportional to log(Vinput). The current flowing on each diode is equal ...
1
vote
1answer
43 views
Input impedance of High - Frequency Amplifiers
I have a question about the choice of the input impedance of a high frequency amplifier.
In general I know from elementary analog electronics courses that it is good for an amplifier (for instance an ...
1
vote
1answer
27 views
XADC Current Sensing Reference Design
Please refer to this reference design for AC701 (snippet below).
The schematics, specifically the current sensing sections in pages 34-36, show this:
I want to understand why, for the REF output of ...
1
vote
1answer
49 views
Is there any way to match Vth of 2 mosfets with different aspect ratio?
For the floating mirror circuit to work properly, the threshold voltage of M1 and M2 must be the same. However, (W/L)1 ≠ (W/L)2. So I thought to get a first order matching I can match L1 and L2 (to ...
0
votes
2answers
61 views
Can Vds ever becomes negative in mosfet?
Due to the symmetry in mosfet, source and drain are interchangeable. So we define the source of nmos is the terminal with the lower voltage. So if we force Vds to become negative the drain and source ...
1
vote
1answer
45 views
Logarithmic Multi - Stage Amplifier
let's consider this logarithmic multi - stage amplifier:
Each stage is an amplifier with this mechanism: if the input signal is small (under a certain threshold), it is amplified with high gain A; if ...
0
votes
2answers
61 views
Check the position on analog servo [closed]
In analog servo, how to set the position with hands then check the position in raspberry pi,yes i know potentiometer can do that but i want with servo motor.
Now, i can increase decrease the speed of ...
0
votes
1answer
28 views
Current sensing using XADC
AC701 Schematics
Refer page 40 of the schematics. Here for Vccint- the regulator is switching at 250 kHz.
page 34 has the sensing signal conditioning for that the inst. amp used is INA333 which ...
0
votes
0answers
49 views
Is ok to use a CMOS Analog multiplexer with voltage from a sensor as an input?
So, I got an analog circuit with an IR sensor that generates a voltage in output. The voltage is a measure that must be read with a microcontroller (I use Arduino Zero). This is the sensor.
As you ...
0
votes
4answers
93 views
Single Supply Class-A-Amplifier circuit to amplify voltage signal alternating around ground
I have a sensor which outputs a voltage signal alternating a few millivolts around zero volts and want to design a circuit which prepares this signal for processing by a microcontroller like in the ...
0
votes
0answers
54 views
Thermistor probes wired in parallel
I have three temperature probes.
Each probe consists of four sensors (NTC) with a common wire.
The sensors wires are connected together and the common wire for each probe is available:
The wiring ...
0
votes
1answer
48 views
Op-Amp settling time in bits
I was reading through this and was a bit confused. What do they mean by
"took forever to settle to 10-bits (0.1%)"?
How is 10-bits = 0.1%
