An ADC is an Analog to Digital Converter. This device converts analog signals into digital form. It is mainly used by the digital circuitry to take analog measurements.

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Can I put negative voltage to the signal input of the ADS8317 A/D if I use a sufficiently large series resistor?

The datasheet of the ADS8317 A/D converter shows that it has protection diodes on the signal inputs, which have a VF of 0.35V. The maximum ratings say "Input current to any pin except supply: -20mA to ...
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2answers
26 views

ADC/DAC Calibration?

What are the methods for Calibrating an ADC/ADC ? Is ADC/DAC calibration is done purely in software ? May I know some hardware methods for ADC/DAC calibration.
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36 views

Vacillating display with ICL7017

for my first project I decided to make a scale using a load cell, the micro load cell 3133 from Phidgets. I also used an ICL7107 as A/D converter and the op amps are LM358. I used a differential amp ...
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40 views

Using Raspberrypi to measure power consumption

I am looking to use the raspberry pi 2 to measure the power consumed by household appliances. I know that the pi does not have an inbuilt ADC. I found that the MCP3008 can be interfaced with the pi as ...
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50 views

Aluminum electrolytic vs. tantalum capacitor for buffering SAR ADC Ref input

I want to use the ADS8317 16-Bit SAR A/D converter and have read through the datasheet. In there, ti recommend using a low ESR 47µF tantalum capacitor to buffer the reference input. Now, my reference ...
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352 views

Purpose of input resistor in ADC circuit

What is the implication of the 1 Megaohm resistor in the schematics attached? Will I be able to detect the condition of the motor (running, not running, stalled)? Part information: MCU ADC (ADC ...
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41 views

high speed ADC interfacing

now I'm pretty lost , recently I've taken it upon myself to try build an oscilloscope for fun. I want to do it with high speed ADCs (unless anyone knows of a better way?) I'm hoping for about ...
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25 views

How do I decide upon the order of SINC filter for sigma delta modulator?

I have simulated a first order sigma delta modulator im Matlab simulink. The clock frequency of the modulator is 20Mhz (oversampling frequency). Now I am trying to convert a sine waveform (50Hz) to ...
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34 views

How to convert 10K Pot raw output ADC data to voltage and resistance from arduino uno?

I have a simple and basic question. I am using Arduino uno to read the output from a 10K potentiometer. I understand that Uno uses a 10 bit ADC, therefore it can display outputs from 0 as 0V to 1024 ...
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19 views

How does the Bias Drive in TI ADS1299 help in noise reduction?

I'm bit of a noob in electronics so please pardon me if this question is too basic. I would like to clearly understand how the signal from the bias drive electrode can help in noise reduction, ...
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94 views

ADC calibration in ATTiny88

I'm writing an embedded app for ATtiny88 - one of its task is to measure voltages of serial connected two 12 V car batteries. The microcontroller is powered from around 4.5-5 V (LM317), measured ...
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42 views

How do I determine my burden resistor for my current sensor?

So I've got a -12v +12v ADC input limit and I've got a 200 turns ratio current transformer. My input Max current is 30A which is stepped down to 150mA. How do I determine the right burden resistor so ...
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51 views

variable or field ' …' declared void

I'm working on an ADC ATSAM3x8e arduino due board. I'm trying to write new .h and .cpp files. How do I create a datatype like ...
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17 views

PWM output pulse variation is not showing in proteus

I want to generate the pulse based on analog input giving to ADC and convert ADC value to PWM signal using LPC2138 ARM processor. I am able to dubug in Keil software in which it works perfectly as I ...
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1answer
63 views

Noise on TL074 / TL084 but not on LM324

I made a circuit that modifies a signal so it can be safely read by an ADC. I'm using an op amp to shift the signal +2.5V so I can measure AC. When I do this shift another signal appears. About 40mV ...
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73 views

Distortion in ADC output

I am working on Intel Galileo board and using its one ADC pin (A5) and one digital GPIO pin (pin 8). I am switching a relay from GPIO pin and using ULN2003A for isolation and LM60 temperature sensor ...
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74 views

How to change analog sensor signal to appropriate levels for microcontrollers?

I have a FUTEK CSG110 amplifier, conditioning a signal provided from a load cell, providing a -3V to 3V signal. I can change this range to my liking, however I will be stuck with a +- voltage ...
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44 views

SLEEP_MODE_ADC interfering with USART (and beep)

On an AVR ATmega328P, once per second I am doing 3 AD conversions immediately following each other with 16x oversampling using SLEEP_MODE_ADC like this: ...
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30 views

Help for VR sensor signal conditioning (variable reluctance signal conditioning)

im trying create a CDI/TCI unit for my Suzuki Bandit GSF400. i need some help for VR sensor signal conditioning section. this is the disc that generate the pulse signal. i have found this image ...
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36 views

ADC output level query

This query is related to my old post: ADC outputs random values to constant input I made further tests, and still struggling. The reason I made a new post is, the query is different. I am using FPGA ...
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130 views

Why modern oscilloscopes use hardware triggering?

I've been learning how DSOs work for the past few days. As far as I understand, digital storage oscilloscopes have trigger circuitry, which usually consists of an analog comparator and a DAC. A ...
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1answer
61 views

Digital Low-Pass Filter When Oversampling Audio

The human ear can hear sounds up to ~ 20KHz. Some ADC's oversample. For example, to capture frequencies up to 20KHz, an ADC converter might sample at 160KHz. The steps are: 1. Filter the audio with ...
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52 views

Sampling many low voltage analog signals

I'm trying to sample 128 low voltage (a few millivolts) analog signals at around 800 samples/second. My original idea was to hook up 128 instrumentation amplifiers to 128 ADCs, but that turned out to ...
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62 views

What is the analog bandwidth of general purpose ADCs?

I am making use of the dsPIC33FJ64GP802's ADC to do Undersampling and for that, I need to know the analog bandwidth of the ADC of this Microcontroller. My signal is around a few MHz. I have already ...
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5answers
289 views

16-bit or 24-bit converters?

I wanna build some DSP effects on, for example STM32F4 processor, with frequency 96 or 192 KHz. Are 16-bit converters (ADC and DAC) enough for that kind of operation? Can I hear a diffrence when ...
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What is the difference between general purpose ADCs, Audio ADCs and video ADCs?

An ADC merely converts an analogue signal to a digital one. Why then do we have special ADCs for audio and video application? What if one was to use general purpose op-amp in them instead?
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60 views

Current regulator with controller?

I want to implement a circuit which allows to regulate the current flowing to the load. I have two use cases: Case 1 is the normal case where I would set the max. allowed current with a ...
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38 views

What is the real ADC Sample rate for Xmega256A3BU or similar xmega controllers

Based on the datasheet of XMEGA controllers, it has sample rate up to 2Msps (2MHz sampling speed). But it is also written that the conversion time for 12-bit need 3.5µs which gives ca. 300 KHz real ...
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21 views

Sigma-Delta RC Filter

I am using a MSP430F427A to measure the voltage across a current shunt for coulomb counting stage of charge monitoring. Just looking at what kind of filter to put at the input of the SD16 ADC, and the ...
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47 views

ADC outputs random values to constant input

I am using ADC (ADS7822) from TI and I have some strange behaviour with it. Below diagram explains the voltage inputs and connections. I was reading strange values with this setup. I removed ...
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273 views

Using a microcontroller ADC to measure a 4-20mA sensor

Question from a SW Engineer again. I've got a device which is mains powered and outputs a 4-20mA current depending on the flow rate in a pipe. I'd like to measure that flow rate with a ...
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2answers
92 views

Design Decisions for using ADC with no VREF

I was looking at Freescale's KE02 processor family, and the MCU designers made an interesting design decision revolving around the ADC that I can't completely wrap my head around. The KE02 has an ...
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44 views

PIC18F Internal reference

I am currently in the middle of migrating a project from PIC16LF1947 to a PIC18F87K22 as I am in need of extra GPIOS and the PIC18 part fits the bill. There is one thing that is nagging me right now ...
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SAR vs. Delta-Sigma ADC

I want to digitise a sweep signal. The frequency range is 1-100 Hz and the sweep time is 2 seconds. The amplitude is 4.08 Volts and an offset of 2.04 volts is added. ADC range = 0-4.04 Volts. I am ...
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55 views

chosing the right Hall effect sensor

For a student project, I need a Hall Effect current sensor. What I am going to do is to charge 8 rechargeable Li-Ion batteries of 3.7 volts in series with 34 volt supply and the buck circuit frequency ...
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78 views

Which one is the better way to feed analog input to my ADC?

I am planning to use an AD7730L analogue to digital converter (ADC) chip, with a quarter bridge circuit. Everything was on the track until I realised something, which indicated that things were ...
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78 views

Use GPIO to disable voltage divider

I'm using a voltage divider to read the battery level of a wireless sensor platform using STM32L151. I'm shooting to use 20k for R1 and 10k for R2, to be under the 50k limit of the MCU's ADC ...
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62 views

Getting the desired output voltage swing from the op amp output

I am designing a microphone preamplifier circuit. I have used op amp OPA 37 which amplifies the signal coming from the microphone to be used by the ADC. The usable voltage range of ADC is 0-2.5V. I am ...
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63 views

ADS1278 Noise level

I have been using ADS1278 TI ADC, after I made the digital side work with my processor, I shorted the + and - of the analog input for a channel to check the noise (used recommended capacitors for ...
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61 views

cirrus/wolfson wm8731 - Connecting Analog Input to Codec

I am currently working on an embedded audio processor project based on the stm32f4discovery board and the wm8731 codec from cirrus/wolfson. I was wondering if anyone here is familiar with the codec ...
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55 views

Reading a 1.2V-8.8V Signal into a 5V Arduino Input

An analog DC signal that ranges from 1.2V to 8.8V (from a thermocouple amplifier) is to be read from a input pin on the Arduino that reads 0V to 5V. Other that using a potential divider consisting of ...
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4answers
297 views

Question about 1-bit Analog-to-Digital Converter

I am working on a research project, and for a part of it I have to turn an analog signal into a digital one. Now, electronics is not my forte so I don't know what I am doing and am feeling around in ...
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Using the ADC on Cerebot mx7ck Pic32

I'm looking to use the ADC on the cerebot mx7ck (pic32) dev board to sample 3 input sine waves on three separate channels. However when I run my code, it appears as if I get the same sine wave from ...
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40 views

Reading analogue input using digital GPIO

I'm using soil hygrometer to measure soil moisture. Since I don't have adc I'm using This method. Please tell me how to connect resistor and capacitor along with amount of resistance and capacitance. ...
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1answer
56 views

Use reference voltage as power suppy

I am using MCP3202 which does not have Vref as independent input. The datasheet states that the current consumption is: 550 μA max. active current at 5V Can I ...
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3answers
92 views

Measuring a voltage that is higher than your reference voltage

Question: How to measure an input power rail? Let's say I want to build a circuit that switches in a load that draws 1A from a 5V power rail (that is the supply for the device) and then measures that ...
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61 views

Low Noise Using Opamp And Photodiode?

I'm building a small sensor setup that is able to measure the transmission of light through a (clouded) solution. I currently have a laser light that shines through the solution and a LDR on the ...
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ADC amplifier gain dependence on microcontroller operating voltage

I was just curious about how dependent the gain of an internal ADC amplifier of a microcontroller is on the supply voltage? The variation I was thinking is 3.3V instead of the values given at 3V. The ...
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93 views

ADC value conversion

I am getting full scale ADC value from 0 to 16348. I am trying to convert it to 4-20mA and then to 0-25 bar pressure, as I am ultimately measuring pressure. I am ...
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1answer
55 views

Changing ADC clock speed does not change sampling speed [XMega]

I am trying to measure how fast my ADC samples arrive on an XMega128A4U. I have set up a timer and the ADC, and each time I have a result I let the DMA pull the CNT register from the timer and the ...