Questions tagged [analog]
Analog circuits have a range of voltages, rather than just two as in digital logic.
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How to design differential sensing analog front end for self capacitive touch panel [closed]
Please tell me how to design circuit of analog front end for self capacitive touch panels by using multisim or ltspice software, show me the circuitry or its connections
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Barkhausen Stability Criterion and when feedback can be considered positive
My analog design book says the following:
"As a signal \$ S_\epsilon \$ propagates around the loop and returns to the summer \$ \Sigma \$ as \$ S_f \$, it experiences a frequency-dependent phase ...
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AD8304 strange behaviour with low current
I am currently experiencing a strange behaviour from my AD8304. I am using the AD8304 evalboard (the evalboard is described on pages 18 and 19 of the datasheet). To test it, I had connected a Keithley ...
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How to design a rail to rail push-pull buffer? [closed]
In 180nm technology, I can't get the output from 0 to 5 volt for the input (0-5V.) The maximum output obtained is 1.64V to 3.46V.
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What is the purpose of loading an analog input?
Theoretical question: I have seen in many analog signal circuits that the analog input pin is pulled down through a resistance. Sometimes it is also pulled up and sometimes there is a capacitor ...
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How to properly ground an old turntable and tonearm?
I have a specific question about proper grounding of an old turntable that hopefully has some general merit for such older devices.
This question came up while I was inspecting the wiring of the ...
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Cadence Virtuoso CMOS layout: MIMcap become unrecognised after instantiating a new component
I have a really weird issue with the layout of my design (TSMC 0.18um BCD). I have three components (A, B and C), all of which are LVS and DRC clean and sitting in their own respectable NBLs. ...
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I need clarification for an audio power amplifier circuit component
Below is the block diagram of my first design using an audio power amplifier.
The input to the audio power amplifier comes from an SC200 module by Quectel.
The output of the PA is connected to a ...
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Reverse engineering a 1.5 V spy earpiece [closed]
I am very interested in spy earpieces. They work on 1.5 V and amplify EMF signals generated by a nearby device. I wanted to get a circuit and re-create the spy earpiece but was not able to find ...
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Cascode current mirror transistor biasing
I'm having trouble intuitively understanding how a MOSFET cascode current mirror functions.
I understand that the purpose of M3 is to shield M2 such that variations in applied voltage do not affect ...
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Back calculating the input from output signal chain with an isolated amplifier and opamp
We are measuring the voltage of a charger using the below circuit with the help of an ADC present in a microcontroller.
The value of charger voltage is required for some other applications. The value ...
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How to set the output impedance of this circuit?
Assuming no biasing, would setting the Re to 300 Ω be the proper method of impedance matching?
simulate this circuit – Schematic created using CircuitLab
I figure that at some point, a ...
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Boost converter output formula and component values
I want to build a simple boost converter for learning purposes that outputs 12V/1A from a 5V/2A source. A simple boost converter has an inductor, diode, capacitor and some transistor that can be ...
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TI Design note Differential to Single-Ended Conversion clarification needed
The below image is from this TI design note.
When I did my own calculation for \$V_\text{out}\$, I obtained a different equation (given below).
$$V_\text{out} = (V_\text{outP} - V_\text{outN}) \times ...
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How does Vds affect the overall transconductance of this OTA?
I am trying to determine the sizing of transistors in the OTA as shown below, using the gm/id methodology. I wanted gm1 and gm2 to have much larger gm than the other transistors to reduce noise. I ...
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If using these components, can a circuit still be defined as "analog"?
Taking a circuit using transistors, CMOS dividers and monostable multivibrators, can it be considered as analog one or it becomes digital?
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Correct way of referring to property of a component in an equation
What is the correct way of referring to voltage drop of a diode in an equation? For example I want to show the output voltage of the following circuit in an equation Imagine that the diode is labeled ...
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Analog audio amplifier schematic
I am a complete noob in electronics and I have to design an analog audio amplifier (schematic in Capture CIS and calculus) for my CAD's semester project with the given input data:
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How to detect voltage peaks above a set threshold?
I have a power source that will generate voltage peaks for a very short amount of time (around 20 - 100 Microseconds long). I am trying to develop an electrical circuit that will capture the peak ...
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What does this table mean in the context of an ADC
I found this ADC. I came across these noise tables.
My questions:
In Table 1 how are the paratheses values (uVpp) calculated?
From Table 2 what do those values mean in practical terms?
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USB Type-C sink states
I'm a Digital engineer. I'm trying to understand how to write a testbench to verify the fsm state transitions in USB type C when acting as a sink, sink with accessory support and sink with try_sink ...
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Understanding Bode Plot of power supply loop
I am trying to decode the bode plot of a feedback loop of power supply measured on Bode 100 (network analyser) in 'intuitive manner'.
1. High gain (60 to 40 dB) at lower frequencies (0 -100 Hz) ...
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How to use two or more ultrasonic transducer drivers?
My circuit is below, it has two ultrasonic transducers, transformers and drivers. The transformer is B78416A2232A003, the transducer is MCUSD14A40S09RS-30C, the driver is PGA460-Q1. Digital interface ...
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Why did this PIC circuit short circuit?
I have short circuit problem in an analog reader circuit with a PIC 18F4620.
There is a potentiometer connected to pin AN0. The resistance value of the potentiometer is shown on a 7 segment display (...
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Standards for measuring analog audio signal devices
I'm making a Analog Channel Strip for a project. I'm searching for standards that let me or give me an advice of how to measure Dynamic Range, THD and THD+N, SNR, Frequency Response and input/output ...
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BJT selection for the reference circuit
I have simulated the below circuit in LTspice and found that the BJT (Q203) is having less power dissipation (~1mW) then the Q202 BJT.
However, the designer selected a 200mW package for the Q203 and ...
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How can I decrease the update rate of the analog conversion?
I'm working on this analog converter circuit. The potentiometer is connected to pin AN0. The resistance value is shown on a 7 segment display. The circuit works fine but the ADC's update rate is too ...
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Trying to ground ADC0832 properly
I trying to use ADC0832 for voltage and current measurement on Raspberry Pi 4, previously I was using MCP3008 for that purpose. But I want to simplify the system.
So, I am trying to implement ADC0832, ...
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Op-amp high-pass filter and low open-loop gain at higher frequencies
How can a high-pass filter work when the open-loop gain of an op-amp completely attenuates from a certain frequency?
I understand that the open-loop gain of an op-amp is what limits every closed-loop ...
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ADC Error RSS'ing Efficacy
Typically... when doing DC ADC error budgets, I've always just done worse case calculations assuming offset error applied, then multiplied by max gain error, and then INL added too... all with ...
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How does a current mirror work?
I'm trying to understand how current mirrors work.
In the text book Microelectronics by Jacob Millman, section 3-11, example 3-8, there is a picture of a current mirror:
They said if we consider \$V_{...
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Why do we use a voltage divider to measure the voltage of a thermistor? [closed]
Can someone explain to me when and why I should use a voltage divider when I design a circuit?
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Would more connectors introduce more noise for low-frequency current signal?
General question
When measuring the weak amplitute low-frequency (DC) current signal (in 0.1 - 1 uA) transmitted through FFC cable and connectors to a PCB with transimpedance amplifier (TIA) and ADC, ...
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Help with TP2825
I want to create a DVR based on the PB1126 chip using the TP2825 encoder. This encoder performs very well the auto-detection of cameras CVBS, AHD, etc.
On the Internet, I did not find information on ...
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Looking for a component that accepts a broad range of discrete values (e.g. 0 to 50 VDC) and outputs a LOGIC HIGH; otherwise output is LOGIC LOW [closed]
I am looking for a component that will accept multiple discrete values ranging from 0 to 50 VDC, but it doesn't have to be 50 VDC. I am looking for a broad range. This range could be 0 to 30 VDC or 0 ...
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How to have sharper rise for ideal filter frequency response in matlab
I am writing about analog filters in my blog and I decided to plot the frequency responses using matlab, representing the responses using step functions. But matlab uses heaviside function which does ...
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Inaccurate voltage reading from MCP6234 op-amp buffer circuit with Seeed XIAO nRF52840
I'm facing an issue when trying to read the voltage output from an analog sensor (current transformer) that has a DC voltage output of 0-5 V, using a Seeed XIAO nRF52840 to read the output using its ...
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Why do we want the input devices to dominate the thermal- and flicker-noise as well as mismatch?
I have thought about it and still cannot find a good reason for it.
Why do we want the input devices to dominate the thermal- and flicker-noise as well as mismatch?
This is from Tradeoffs and ...
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Measuring low resistance (0.1 Ω range)
The application is to light up numbers of LEDs depending on the measured resistance, eg. 1 LED for 0.1 Ω / 2 LEDs for 0.2 Ω.
I'm quite new to circuitry so I'm thinking of using four terminal sensing ...
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What does the value of R_t represent in Balanis' bowtie antenna design equations?
I'm using Antenna Theory: Analysis and Design by Constantine Balanis to aid in the design of a wideband antenna. I believe a bowtie antenna will satisfy my necessary bandwidth, however Balanis notes ...
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Switching 4 SCART inputs: analog switch ICs or relays for signal quality?
I need to build a SCART switcher (like this one here: Lotharek's Hydra Revised, but with fewer inputs, simpler - no fancy features, just switching between a few inputs, and cheaper). I have some ...
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Analog voltage level shifter
I am looking for a way to shift a low analog voltage level to a higher analog voltage level. For example, input 0.53 V and output 1.53 V (increase by 1 V) or input 1.38 V and output 3.38 V (increase ...
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Connecting bulk capacitor board via header or standoff?
I am routing a 2 board design that are stacked on the top of each other. The lower board (inverter board) contain the power transistors and a separate board contain the bulk DC-link capacitors for the ...
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How to use a tristate buffer when negative voltage can appear on its output?
This is a followup to Injecting a UART TX output signal to an audio input pin, without messing up the audio?
The preferred solution for TX was a tristate buffer, which makes sense, until we recognize ...
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Battery charger circuit confusion - drive and compensation
I'm building something that is going to have Li-Ion batteries so I'm trying to learn how a battery charger actually works. I've been looking over the datasheets for the BQ2000 and the BQ2954. I will ...
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Generating an analog sawtooth ramp for PWM
I came across the circuit below:
Source
I can't seem to understand how the circuit works. They even say that one can set the maximum duty cycle. Kindly explain to me how the circuit works. I would ...
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DC voltage 48 - 58 V to 0 - 10 V scaling
I have four 12 V lead-acid batteries in series and want to measure the total voltage. I'm interested in the 48 to 58 V range. How can I convert the range to represent it with a 0 - 10 V volt meter?
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Issue in rail to rail opamp as buffer
I'm using LTC6090IS8E#PBF as buffer. Following is the circuit. Actually my input is 100 V and I'm attenuating it to 60 V using voltage divider. Then 60 V is given to non-inverting input of LTC6090IS8E#...
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LTspice OTA simulation does not work
I am trying to simulate a balanced OTA with TSMC 350 nm technology in LTspice. Here is the TSMC 350 nm library for LTspice. I designed the balanced OTA topology below:
Thd output current is almost ...
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What's wrong with my pressure sensing circuit?
I designed a PCB with several modules. Relevant for this question are:
MCU (STM32L476ZGT3)
2 analog pressure sensors in the following configuration
RG has 0.1% tolerance.
As you see in the figure, ...
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