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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High frequency, low noise clamp circuit

I have an analog circuit that outputs voltage between 0-5V. A simple representative circuit is given below. The ADC can tolerate up to 4V and the interesting signal that I like to digitize is ...
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Compare optical Sensitivity of two sensors

I have two different sensors. Both have 16-bits ADC, both operate at Vdd = 3V, but their dynamic range is different. One has dynamic range of 50M:1 with gain range of x8 and the other has 500k:1 with ...
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ADC with programmable quantization levels

Does anybody know if there are ADCs with programmable threshold levels? The continuous signal is a radar signal which is to be digitized with an ADC with controllable qunatization levels. I am not ...
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How to connect the power for VREFSD pin and anlog pin in STM32F3273 (ARM Cortex-M4) for SDADC application?

I have an analog amplifier which is powered at single-supply power and have an analog ground of 1.25V. I want to perform sdadc for my analog output. I am using STM32F373 (48pins), which is an ARM ...
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Two analog power planes for same voltage

I'm designing a board with LAN8720 and LPC1768. LPC's ADC and LAN's magnetics connections require analog 3.3V power. Should I separate these two analog power planes with a ferrite as I separate it ...
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44 views

Differential ADC where input goes below ground rail?

I've been reading up on differential ADCs but haven't quite wrapped my head around them. I'm a hobbyist with no real training, you see. I'm wondering, is it possible to use a differential ADC with ...
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50 views

ADC analog pin connection

That is my circuit: Input: 400V DC U2_1: LTC1285 (ADC) http://www.farnell.com/datasheets/1575635.pdf U2_2: IL261 (digital isolator) http://www.nve.com/Downloads/il260-1.pdf The circuit behavior ...
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64 views

I want to attenuate my incoming signal whose value is around ±80V to ±0.8V

I have used this circuit configuration to attenuate the signal. Will this work without clipping the signal? Is there any alternative to this? I have to give signal to ADC as a input whose input ...
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29 views

Problems connecting differential ADC to SPI chain [duplicate]

I need to connect 3 devices with SPI in a daisy chain configuration.1 master 2 slaves. the first slave is typically connected to the master: SCK-SCK MOSI-MOSI CS-CS The second slave on chain have no ...
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71 views

STM32F1 Can't I use the internal voltage reference as the ADC reference?

There seems to be a badgap voltage reference built-in in the STM32F1 microcontrollers (on ADCx_IN17). Coming from AVRs it seems to me very strange that it's not possible to use this reference as the ...
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Noise at 2^n transitions

I am sampling a video signal from a linear imager. I noticed when the illumination is just at the intensity when the ADC increases by another MSB bit at the output, the noise occurs. That is, when ADC ...
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93 views

Isolating an analogue input using ADC/DAC

I'm looking into isolating an analogue input coming from field equipment and interfacing to a PLC analogue input module. The input will be of the 4-20mA range (1-5V). There are a few ways to approach ...
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48 views

Microcontroller SPI Using DMA with Seperate Chip Selects

I have a microntroller that has DMA (Direct Memory Access) connected to 4x identical external ADCs. All ADCs use a common conversion clock, and have their sampling synchronized. The ADCs have a data ...
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91 views

Differential ADC input buffer

I am trying to make 10Mohm of input impedance into a ADC (CS5530). I am planing to use differential input buffer to ADC so I am trying to use TI's document as reference. I tried the one differential ...
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390 views

What to do with unused analog inputs?

I am working on an application using ATmega328p atmel microcontroller. I started with the 28 PDIP version, but now I want to use the 32 TQFP, which I noticed has 2 extra inputs after compiling my ...
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70 views

Porting MikroC code to MPLAB for PIC16F1508 adding extra noise to ADC

I decided to start using MPLAB with XC8 after I started reaching the 2k code size limit in MikroC. The problem is that since all the Mikroc libraries are proprietary and there are no libraries ...
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How to find the dynamic range of ADC?

I bought a Analog to Digital Converter but did not gave much attention to Dynamic range. The resolution is 12 Bit. Minimum input voltage is 0V and maximum is 5V. The problem is I don't have the ...
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Should my external analog input be isolated?

I want to build a device that samples analog signals from various measurement instruments via their analog outputs. The instruments have their own power supply, and all devices are powered from the ...
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59 views

Quantization levels and SNR

Im' trying to build a big picture of telecommunication and i'm stuck in a topic, related to digital communication. But the problem is that i can't go too deep into the topic because it is imensely ...
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56 views

Can I switch between two analog references to read signals with different ranges with the ATmega328P?

I want to read two voltages of different ranges with an ATmega328P ADC with the highest resolution possible: The 1st signal varies from 0 to 1V. It's the output of an LM35DZ Temperature Sensor. I ...
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81 views

Separating Digital GND from Analog GND

I'm connecting CdS photoresitor and ADC (MCP3204) to the RPi. And MCP has DGND and AGND. I am about to connect both GNDs to the GND on RPi's GPIO, naively. Is that problematic if I want to read the ...
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43 views

Differential Pressure sensing circuit

I'm trying to understand a differential pressure sensing circuit that I have. Have attached rough design sketch as well. Sensor used is "10 INCH-D1-MV-MINI" by Allsensors. Output span is 20mV for 10" ...
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66 views

Why use an actual lock-in amplifier

Why not just use two ADCs (say GPIB from digital multimeters) and use them to collect the data. Afterward, you can just emulate the LIA by empirically determining the phase offset between the signal ...
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Using the raspberry pi to measure multiple electrical circuits

I am looking to use the raspberry pi to measure the power consumption of multiple household electronics and record the information to analyze later on. However, I'm not sure if it's possible to ...
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No comunication beetwen Personal computer and ftdi2232d

I would interface my computer with both FTDI 2232d (master) and ADC (slave). I see the AN255 and I wrote my program application in visual basic. I'm able to open device and send some codes ...
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This automated light system is slowing down randomly

A PIR sensor sends input to the AVR (ATmega 32A), when input is received and the ADC (LDR) is below a critical value, PB0 is to go high to switch on a relay. A timer counts seconds so that the relay ...
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40 views

Sense existing vehicle TPS with AVR ADC

I have an issue sensing the throttle position sensor voltage if the sensor is already being used by the vehicle's own ECM. Namely, the vehicle ECM stops responding to the throttle input after a period ...
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32 views

Real Time Data Capture System

I would like to build a system which could capture an analogue waveform data in real time. For the basic data acquisition system I can use an ADC to digitise an analogue waveform and store this in a ...
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73 views

Level Shifting & Amplification

I am trying to design a crane load (Weight) measuring unit using motor current measurement technique. For some reasons we can't use load cells here. Part of schematic I have drawn here An air core ...
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82 views

Micro Converter with ADC/DAC peripherals

I bumped into an interesting device ADuC841. It seems to be a microcontroller with extensive ADC/DAC peripherals. Since I am not experienced and did not have to use combination of ADCs and DACs, going ...
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77 views

Rise/fall time constrains for ADC?

Does the sampling clock rise/fall times for ADCs matter, or they can be virtually 0 seconds? Can they be slow? In particular, I could not find anything about rise/fall time constrains for AD9235. ...
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118 views

PIC18f45k20 ADC - always returns zero

I'm trying to read a value from a PIC18f45k20 ADC but I always get a zero. It has to be my config that is wrong but I can't see where. I've checked the data sheet and googled (lots of conflicting info ...
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Are 4-wire resistance temperature detectors sensitive to ambient temperature?

We're using a TI LMP90080 as an ADC to read a 4-wire resistance thermal detector (RTD) in the following circuit: The problem we are having is that when the ambient temperature changes, especially ...
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Internal resitance of a battery and SOC related?

How do you find remaining SOC of a battery, say 12V 100 Ah? Is it possible by monitoring internal resistance of the battery? Or is there any better way (logic wise) used in industries? I'm using an 8 ...
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101 views

Stuck codes in samples from ADC

I am currently testing a 16-bit DAC and a 18-bit ADC. In many tests I have found the ADC to get "stuck" at codes, especially at the ends of the input range. Both the DAC and ADC operate in bipolar ...
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ADC and Pre-Amp Suggestion for RBpi

I want to receive VLF signals (between 15kHz to 30kHz) with my RBPI. So I can found only this antenna: Miniature Very Low Frequency Antenna ANTM1. This miniature 6 inch long antenna can be ...
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Problem with ADC of Atmega16A in differential mode

I am having some problem while using ADC interface of Atmega16A. I want to calculate RMS voltage of the power supply coming to my house(usually 250V, 50Hz) and display it on LCD. I am using the ...
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Separating a PORT into in/out and getting random nums?

Using ATMega1284 I want to generate a random number from 0-7 (maybe more range). This is the main concern. As long as it "feels" random its fine. And it could resolve the rest of my issues... anyways ...
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What microcontroller has 20 or more ADC pins?

I'm looking for a microcontroller with at least 20 ADC pins. Most things I'm used to using like an Atmel or Arduino have only a handful of ADC. I need to decode 20 analog wave forms being used to ...
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SX1509 Analog to Digital Converter?

I purchased this product: https://www.sparkfun.com/products/11502 I've wired it up to 5 membrane pressure sensors which provide variable resistance depending on the pressure exerted. However I'm not ...
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103 views

op amp level shifter no input situation

I tried out op-amp level shifters on web. The ones recomended here as well but there is a problem when no input applied. The output voltage is no seperable from the case voltage applied. As i ...
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Weird samples from SAR ADC

I am playing around with some SAR (Successive Approximation) A/D-converters. I have made a test circuit where I have a 16-bit DAC from Texas Instruments (R2R-based) and an 16-bit SAR ADC from Analog ...
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Microcontroller input pin impedance/leakage current

I'm using the internal ADC of an ATMEGA324PA to measure the voltage of a low power 3.6V battery. The ADC is referenced to it's internal 2.56V and I need to use a voltage divider on the battery. To not ...
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98 views

Connect VLF antenna to raspberryPi

I want to connect two VLF antenna (given below) to a RaspberryPi using it's GPIO ports with a MPC3008 ADC. Desired frequency range is between 3kHz to 30kHz, and MPC3008 supports 200,000 samples/sec ...
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55 views

ADC “internal” overvoltage with gain, ADC overvoltage above Vref

I want to ask about maximum input voltage for ADC in 2 cases I'm using MCP3424, with internal differential amplifier (gain 2, 4 or 8). Reference is fixed 2048mV. What will happen, if I apply 2V to ...
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51 views

Adding trigger functionality in for FPGA in ADC capture board

I'm using the LM97600RB board from Texas Instruments to capture data signals and this board contains an ADC as well as a Virtex-5 FPGA. I'm trying to add a trigger functionality to the board using an ...
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Electret Mic preamp for sampling and FFT

I'm working on a project in which I want to be able to have some light effects based on the ambient music. I was thinking of sampling a mic and running an FFT, and set effects according to that. Is ...
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PIC16F88 - compare ADC results with a constant value

I am trying to write my first program in assembler for PIC16F886. The program is supposed to do the following: Read ADC value on channel AN0 If the value is smaller than 128 - turn LED off Otherwise ...
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How can I change a +/- 5V Sine Wave to a (0 to 5V) signal for an ADC

I've been digging into this for the past couple of days and I could really use some help. Here's the details: Input: Sine wave going from +5V to -5V Output(needs to be): 0V to +5V [0v when input is ...
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199 views

On the fly digitizing audio from analog audio jack

If I am correct, I believe that all normal audio jacks (like the ones you have to your PC, traveling to your speakers) are analog. Is there a way (perhaps with a high speed ADC) to convert it to ...