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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How does a Successive Aproximation ADC Handle Negative Voltages?

First, apologies for what must seem a simple question to most of you. I do understand the SAR algorithm. And Two's complement representation. My question is algorithmic. When a negative voltage is ...
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193 views

Anti-aliasing filter closer to amp or ADC?

I'm designing a board with several amplified analog signals being fed into the internal ADC of a PIC DSP (dsPIC33FJ256GP710). Because of the board size/shape restraints, the analog buffers can't sit ...
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47 views

How to use an external ADC with an AVR ATmega [on hold]

I have got the ATmega162 and the ADC0844 and wired it up like this: simulate this circuit – Schematic created using CircuitLab because the wiring diagram is hard to read here the ...
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57 views

What is the significance of 8 bits in the context of an ADC0808?

ADC0808 is an 8 bit analog to digital converter. What is the significance of 8 bit? What does it represent? Which capability of IC does it represent?
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82 views

Daisy Chaining ADC Sensors

I'm creating a grid of 200+ pressure sensors and need a clean way to get their values back to the master controller without a mess of wires. To me it seems like daisy chaining all the sensors ...
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53 views

Which resistor watt rating to use for this circuit and Arduino 5V?

http://www.skillbank.co.uk/arduino/measure.htm I am looking to build the circuit this guy recommends for making a better analog reference source. I found the voltage reference diode, and now I am ...
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47 views

Strategy for up to 40 ADC inputs using alert feature

I'm working on a project where I want to monitor 40 phototransistors (IR breaker beams), but without having to constantly poll the ADCs. Ideally I'd want a digital pin pulled when one of the beams is ...
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5answers
113 views

ADC implementation

I want to sense the voltage across the resistor R1 (i.e convert it into digital form). I only have comparators available with me and no other hardware (ADC is not available). Is there any way I ...
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68 views

Do batteries have a delay when adjusting to a new load?

So I am creating a battery voltage measure, and it takes a reading both when the battery is in open circuit, and when it is loaded with a 100mA constant current. I have set it up and the reading is ...
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34 views

Globlal Variable Problem: Pic18f4550 and Pickit3 Debugging

I'm working on a project which includes the usage of the A/D converter module in the micro-controller (pic18f4550). I haven't had any problems in the past with the micro-controller using a pickit3 ...
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100 views

Get temperature via ADC of microcontroller

I want to manipulate the physical value of temperature. Here is the characteristic of this µC: Resolution: 12 bits Supply: 5 V Min Mesure: -45 Max Mesure: 75 Min ADC IN: 0.4 Max ADC IN: 4.8 Here is ...
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In PIC24 programming, why does AD1PCFGL = 0xFFDF mean assigning analog to AN5?

I know 0xffdf is a hexadecimal number, but why does the instruction AD1PCFGL = 0xFFDF; mean assigning analog to AN5? What has 0xFFDF to do with 5? How are they ...
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30 views

PLL synchronized ADC sampling

I want to do AC RMS measurement. The input signal is derived from the utility power line, so it's frequency not so stable. So i want to use PLL to synchronize the ADC sample pulses to the input ...
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35 views

Precise Measurement of Noisy Voltage

I'm working on a circuit that will have a current shunt before a device connected to a truck's 12V system. This system can have voltage drift, and large transients during operation. The connected ...
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58 views

ENOB Calculations

I've been having a discussion with a colleague about ENOB (effective number of bits) calculations for DACs and ADCs. We both come across it from different directions (he being more analog, and me ...
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143 views

Is there an ADC with a finite bound on measurement time

Most interfaces to ADCs (analog to digital converters) look like the following: Start the ADC and wait for it to finish the measurement. Buridan's principle [1] says that a discrete decision based on ...
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62 views

Solar power monitoring with Raspberry Pi

I want to measure the current and voltage from a set of small solar panels (about 10V and 100mA but not settled yet) using a Raspberry Pi. There will be between 4 and 6 panels. This project will ...
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35 views

Converting a bipolar signal using an ADC [duplicate]

I want to convert a signal having amplitude +1V to -1V using an ADC in single ended mode. But I am not sure how to use a bipolar signal as input to an ADC in single ended configuration. How can I do ...
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87 views

Reading a gas sensor with range from 0 to 60mV with an ADC

I need to take a reading using an ATmega328P of a gas sensor. The ATmega328p has a built in 10bit ADC giving only 1024 'steps' The data sheets for my O2 sensor are: ...
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How to select ADC resolution, considering input signal SNR and digital signal processing?

What I knew: The ADC resolution selection depends on the ADC inherent noise and input signal SNR. Our application: Very high precision measurement of signals ranging 1kHz to 10kHz. We want to get as ...
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104 views

Inconsistency of ADC output

I am having an issue with my ADC output. I am using: 12-bit ADC integrated in a MCU 3.3V voltage reference. Power supply of MCU, ADC and ADC voltage reference sharing the same voltage rail(3.3V) ...
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83 views

LM339 : why output +5V

This circuit diagram below is given in my book ( written by Coughlin and Driscoll ) . simulate this circuit – Schematic created using CircuitLab Here it is said that at this condition ...
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Trade offs between adc range and amplifier gain design

Edited on 15th,Aug Tradoffs between ADC range and amplifier gain If I want to measure a very small signal with 16 bit ADCs,say 10kHz sine waves with amplitude ranging from 0 to 1uV, I have to ...
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109 views

ADC Reading is much lower than expected

I am using a EFM32GG990 microprocessor and I am trying to get it to read a voltage using it's on-board ADC. I have made a circuit that I wish it to measure, both the loaded and open circuit voltage ...
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66 views

STM32 ADC sampling problem

I'm using the STM32F2 microcontroller, and have a weird problem with the ADC. Seems like the ADC sampling circuit needs a reset to take a sample, as the ADC value quickly drops after the reset. For ...
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55 views

FIR filter output result Interpretation While input is taken from ADC161S626: 16 bit

I have implemented a 20 order FIR Low pass filter, 1000 HZ cutoff frequency on Sparten - 6 FPGA. First I calculate the coefficients in Matlab, Then I directly put them in vhdl code. Here are my ...
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242 views

calculating a burden resistor for a current transformer

Background: I follow a reference design for a single phase power meter (230V, max 3A). The below circuit is to measure current via a current transformer. a CT will be connected to...
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Can an ADS1231 be used in place of an ADS1115?

I have a working millivolt recording device which uses the ADS1115 16-bit adc. I would like to move up in resolution to the ADS1231 which is 24-bit. The Ads1115 is described as an i2c-compatible ...
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216 views

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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63 views

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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79 views

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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81 views

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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52 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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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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65 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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43 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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120 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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338 views

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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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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68 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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127 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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417 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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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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72 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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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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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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56 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" ...