Analog circuits have a range of voltages, rather than just two as in digital logic.

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2answers
315 views

In an ADC what are the units of resolution called?

I have a signal whose full scale output on the 12bit ADC is 4095. If I reduce the signal so I see the output number is (say) 4000 the output has decreased by 95. But 95 what? What are those divisions ...
0
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1answer
17 views

composite (RCA or A/V jack) output Passive splitter

Im trying to connect one CCTV camera feed to a TV and an USB composite encoder at the same time. my question is, would something like this do it? I have doubts about impedance issues, in which case ...
0
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1answer
34 views

MCP3008 (ADC with SPI interface) what to do with unused pins?

I'm building embedded system based on a Raspberry Pi with an MCP3008 for analog inputs. I have few questions regarding the PCB board design. What should I do with unused analog inputs on my MCP3008? ...
0
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1answer
35 views

Does PWM affect current?

How does PWM affect current? Since current is dependent on voltage (higher voltage allows for more current) decreasing analogue voltage reduces current, but what about PWM? If the actual voltage is ...
-1
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0answers
13 views

ERROR(ORPSIM-16316) in PSpice

I am trying to simulate a 2-bit comparator with NOR gates in PSpice A/D. On doing so i am getting a error repeatedly which says: ...
0
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4answers
99 views

High Speed Op-Amp recommendation [on hold]

I am tasked with the issue of driving an IC that wants 5V input signals from an FPGA (3.3V outputs). Now, the most daunting part of it is the slew-rate requirements, with rise time \$t_r = 1.5 ...
1
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1answer
52 views

What is the name for an IC that accepts an analog voltage and outputs a proportional PWM signal?

I want to isolate an analog signal. One way of doing this is to convert the analog signal to PWM, isolate the pulses with an optoisolator, and filter the PWM on the other side. Obviously I could do ...
13
votes
4answers
458 views

Designing a *linear* MOSFET driver stage

I'm looking for a MOSFET driver circuit that can be placed between an op-amp and a power MOSFET to operate the transistor as a linear amplifier (as opposed to a switch). Background I'm developing an ...
0
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0answers
17 views

How to reduce settling time of a signal conditioning circuit for a PIR sensor

I have designed the circuit below to turn on an LED when movement is detected by a PIR sensor. Sometime when movement stops being detected the LED goes off quickly (within 0.5 seconds) and sometimes ...
1
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3answers
112 views

A current controller by regulating the voltage

I need some idea of what type of controller I should use. But, I am thinking of a PID controller. Here is my problem: I have a simple circuit like this one: simulate this circuit – ...
-1
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2answers
51 views

Building a distributed low-pass filter with cutoff frequency of 1hz but the highest frequency of 10^13 hz

How does one build a distributed low-pass filter with cutoff frequency of 1hz and highest frequency of 10^13hz (or arbitrarily high)? In case of lumped circuits, this is easy to do, but in case of ...
0
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0answers
48 views

Constant current circuit messing up

I am working in a startup and facing some major issue with a led driving circuitry in pulse oximeter. Circuit is working fine with non smd components, but heats up to very high levels with an smd ...
0
votes
1answer
28 views

Volume control with DS1807 digital potentiometer?

I'm making a digital synth for a project and I need to wire in an Arduino-controlled volume circuit. Right now I'm outputting a 0-5V audio signal and cutting it down to a pure AC 0.5V signal with a ...
1
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1answer
69 views

Textbook for learning analog IC design? [closed]

I am currently using Carusone's "Analog Integrated circuit design", but this book seems more suited as a reference book for professionals who already know the subject. Are there any good alternatives ...
1
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2answers
231 views

What conditions could be expected to occur if one or both inputs of an op amp are left floating?

Question 1: Can an op amp work with both of the inputs floating? I assume that due to the input offset voltage if both the inputs are floating, the output would be +Vsat/-Vsat. Am I wrong? Question ...
1
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2answers
48 views

Adapting 120VAC High Pass Filter to UK 240VAC

I am looking to build a analog high pass filter with a cutoff frequency of 5.3 kHz. I have found a design which suits my need but I would like to adapt it from the 120V AC, 60Hz and a cutoff frequency ...
3
votes
2answers
289 views

Will two op-amps connected to the same input affect each other?

I've been given the following circuit to build for an education lab. The values of the resistors aren't accurate; they're only to illustrate that the gains of the two op-amps are different. The aim ...
1
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2answers
84 views

What can ECG DC level be?

In ECG signal, to what DC level should i expect? Can it be 3V, at least from time to time? Alternatively, what would be decent input voltage range for the instrumental amplifier for ECG stage?
0
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0answers
36 views

How to (cheaply) generate a low voltage DC analog signal (+/- 14 to 70 mV). 1 mA/cm2

I am looking to generate a low voltage DC analog signal (+/- 14 to 70 mV). I was also looking to incorporate frequency modulation (voltage controlled oscillator?). Would I be able to achieve this ...
0
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1answer
35 views

PIC24F: problem in AD1PCFG register

Im working ADC in PIC24FJ64GA002 microcontroller using proteus simulation. I've a doubt regards AD port configuration register. I've connected a potentiometer in AN12 pin and channel was selected. The ...
0
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4answers
186 views

How To Hold Power ON For Some Time Without Using A Microcontroller or 555?

This is my first question here, so I'm hoping for help. I'd like to take a Momentary event and use it to turn on a device (LED, for starters to model the concept) for a minute (give or take) at a ...
1
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2answers
78 views

Is my Precise Capacitor Ratio Repeatable?

I have designed a 1Mohm, 0Hz-100MHz fixed attenuator circuit (15pf/300pf). I am using 1%, C0G capacitors. There is also a TS5A2053 analog switch connected to the output of the attenuator. The switch ...
3
votes
2answers
57 views

When should I be considering an operational transconductance amplifier (OTA)?

I found a few questions roughly related to this: How is a transconductance amplifier used to measure current? Operational Transconductance Amplifier Input Configurations Dead or alive: Operational ...
0
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0answers
54 views

Can someone explain this Arduino theremin circuit to me?

I'm going to try building an Arduino theremin via the instructions here, but I'm a bit nervous because there's a lot I don't understand about the circuit. For reference, I have a degree in CS and am a ...
1
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2answers
62 views

Designing Precision Instruments: what to self-calibrate, what to guarantee by design

Context: I am working on a precision instrument (digital output) to measure current to systems, in the range between 300nA and 300mA (120dB). However, I hope that this question can be answered ...
6
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1answer
75 views

Should I be concerned when loop gain rises back above 0dB on simulation?

Interim update Okay, I just realized I screwed up on the simulation. When I added \$C_{bp}\$ I upset the "break" in the feedback loop necessary to get the loop gain. The left-side lead has to go to ...
1
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1answer
68 views

Why does smaller step show instability better?

I was stability testing a simple op amp circuit by applying a square wave to the input and looking for ringing etc. on the transitions. I figured, hey, I'll give it a big whack, say from 0 to 5V, ...
2
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3answers
71 views

How do I determine \$R_o\$ for an op amp?

I understand that when driving a capacitive load with an op amp, the output resistance, \$R_o\$, of the op amp interacts with the load capacitor to form a low-pass filter, introducing a pole in the ...
17
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9answers
2k views

Why are op amps used so frequently in analog electronics?

I've read in several books and papers the observation: "Op amps are the bread-and-butter of analog electronics", or "... op amps are the most commonly encountered building block in analog circuits ...
0
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2answers
178 views

what is Rail to Rail supply? [closed]

I am new to analog electronics and I have been hearing this word from my seniors they always talk about Rail-Rail supply while working on some amplifiers and Opamp,also while calculating and designing ...
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0answers
64 views

Single to many analog signals

I am trying to drive two piezo inkjet print heads with an analog waveform varying from 0-40V, with a slew rate of 15V/us and a complicated waveform of a duration of ~20us. When printing only one ...
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0answers
32 views

How to correctly ground analog with concatenated PCBs

I want to ask how should I ground devices that have an Analog and Digital ground when I use multiple boards. I found sensor packages(for sensor packages I don't mean ICs, but small boards with min. ...
0
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0answers
50 views

Ultrasonic distance sensor with no microcontoller

For a task we have to come up with a way to use a 40 kHz ultrasonic transmitter and receiver pair to measure distance. The output must be an analogue signal proportional to the distance to the object. ...
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1answer
114 views

How can I easily convert an analog signal to a digital signal?

I've tried searching for an answer on this topic but I must be phrasing it wrong because I can't find anything. I have a voltage range of about a 1 volt. I want to pass it through an Op Amp (or ...
1
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3answers
69 views

Electrical noise sources in farms

I am designing the data logger of a solar-powered automatic weather station that will be installed in farms. It's used to gather data from environmental sensors (wired) and send it to a host using the ...
0
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1answer
70 views

How to transmit data from an analog multiplexer to an RS232 COM port on a PC

I am having trouble understanding how to design a circuit that will transmit multiple analog data signals to a computer through one RS232 COM port. The analog data is a simple voltage reading from ...
4
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7answers
355 views

What makes a circuit digital?

I've been trying to understand how a circuit becomes digital. I understand the different between an analog signal and a digital signal, but I don't see where digital circuits come from if all the ...
0
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2answers
53 views

An COTS solution for delaying a 120kHz analog signal?

Looking for some cheap method of adding a 350uS delay to a pulsed sine wave. It would be useful to emulate a pitch-catch ultrasonic distance measurement setup
0
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0answers
40 views

Switching low-voltage AC signal from microcontroller

I have a 5V 10MHz AC line which I need to turn on/off from a microcontroller. The microcontroller will be powered by the same input signal (through rectifier). What is the best way to do that?
2
votes
2answers
82 views

Generating microvolt signals

Is there a common way to generate relatively accurate microvolt (like 5uVpp, 0.5uV resolution) waveforms with bandwidth under 4kHz, output impedance around 1k? I can't think of much more than ...
0
votes
1answer
20 views

Calculating the Power of the Upper Sideband

I solved a question in a book that goes like this: If the carrier power is 1000 watts, what is the power in the USB at 70.7% modulation? I solved it using the formula: $$ P_{USB}=\frac{m^{2} ...
0
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0answers
38 views

Conditioning negative ADC voltage with separate AGND and DGND

I was looking to condition a negative voltage analog input for an ADC and I saw these two posts describing a voltage divider circuit to do so. How do I sample a -2 V to +2 V analog signal with a PIC ...
1
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1answer
54 views

I want to energize a solenoid based on a temperature without arduino?

I want to open a 12V solenoid valve and close another based on a temperature reading I will be getting from the lm35dz temperature sensor. I should mention, the solenoids are normally closed and they ...
1
vote
1answer
54 views

Brightness control with PWM dimming LED driver LM3406/06HV

I have an changing input voltage. I would like to feed it into LM3406 and have varying brightness from the Led. So I go through the datasheet. However,the only information and characteristic of the ...
0
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1answer
39 views

voltage at the analog input of micro

simulate this circuit – Schematic created using CircuitLab In the circuit the current i1 is flowing from external device. Now my doubt is what is the voltage developed at the analog input ...
0
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2answers
76 views

Voltmeter scaling resistor front-end and ADC calibration coefficients

I'm designing a voltmeter and current measurement system that forms part of a electronic load. Lets tackle the volt meter first. I'm using a 16-BIT ADC (AD7708) and want to measure the following ...
0
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1answer
58 views

Power rail decoupling caps for analog circuitry

First off, the terminology I'm using could be complete rubbish - I'm still learning I have a mixed signal board for measuring bio-signals. The 4 layer board will have a split ground plane, analog ...
2
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2answers
121 views

Is it feasible to synthesise sound with analog circuitry these days?

A friend of mine who is a layman in terms of electronics asked me to teach him how to synthesise audio with some analog circuit and how to build it. For some reason it has to be analog. Probably ...
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1answer
48 views

AD5933 analogs for 4-terminal measurements

I'm going to do bioimpedance measurements, and it seems that AD5933 chip (http://www.analog.com/media/en/technical-documentation/data-sheets/AD5933.pdf) has many useful features for this. However, ...
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0answers
32 views

Expression of Output voltage in Triple tail cell

I was reading this article in one of the journals. In this a D-Latch has been proposed from a basic triple tail cell. Now when i was going through this i saw the implementation of AND gate with this ...