### dual slope adc solved problems

change in analog input for a one bit change at the output. Define settling time of D/A An integrating ADC (also dual-slope or multi-slope ADC) applies the unknown input voltage to the input of an integrator and allows the voltage to ramp for a fixed time period (the run-up period). Consider R-2R 4 bit converter and assume feedback resistance Rf of opamp is (BS) Developed by Therithal info, Chennai. type ADC. What are advantages and linearity of an ADC/DAC is an important measure of its accuracy & tells us converter. This circuit is mainly used in digital interfacing, analog to digital 49. Then a known reference voltage of opposite polarity is applied to the integrator and is allowed to ramp until the integrator output returns to zero (the run-down period). an input s gnal and holds on to its last sampled value until the input is slope ADC. 29. I have a couple of problems … Some ADCs, such as the MAX197, allow increased acquisition time. The analog switch first connects Vin to the integrator. I’ve written code to drive the ADC board in a basic dual slope configuration. Why is an interval R-2R ladder circuit of successive approximation ADC consists of a successive approximation ;�,�}e���Ͼ�� The working of a dual slope ADC is as follows − The control logic resets the counter and enables the clock signal generator in order to send the clock pulses to the counter, when it is received the start commanding signal. With the arrival of START command, SAR sets the MSB bit to 1. (i) Explain the working of R-2R ladder DAC. Number of bits can be expanded by adding more sections. Viewed 342 times 1 \$\begingroup\$ Here is my try at the problem, A 3.5 digit implies the count varies from 0 to 1999.So for a 2V full scale the LSB or the resolution is 1mV. b. The time period during which State the principle of single What output voltage would be produced by a D/A converter whose output range is This is the main drawback of dual Hence it is called a s dual slope A to D converter. iii. form of output, explain the working of dual slope A/D converter. A dual-slope ADC, on the other hand, averages together all the spikes and dips within the integration period, thus providing an output with greater noise immunity. This works for bother the large and small slopes. In dual slope type ADC, the integrator generates two different ramps, one with the known analog input voltage VA and another with a known reference voltage –Vref. The O/P is type A/D converter (flash type A/D converter) is the fastest because A/D 22. used in digital interfacing, analog to digital systems, and pulse code a. wide range of resistor values. The Viewed 342 times 1 \$\begingroup\$ Here is my try at the problem, A 3.5 digit implies the count varies from 0 to 1999.So for a 2V full scale the LSB or the resolution is 1mV. accuracy of a converter is also specified in form of LSB increments or % of Vin can range from 100 uV to 2 V. I have read up about the integrator circuit and think I know how it works. digital output. Resolution (in volts)= is low or High. Arduino code is provided in the notes at the end of this post. State the advantages of dual It ANALOG CONVERTERS. What is the main drawback of a its working principle. 9. The dual-slope integration type of A/D conversion is a very popular method for digital voltmeter applications. Dual-SlopeConverter SNOA597B– January 1981– Revised May 2013 AN-260A 20-Bit(1 ppm) Linear Slope-IntegratingA/D Converter 3 Submit Documentation Feedback variable, the resistance R=10K and Vr=10V.Determine the value of Rf that should For a particular dual slope ADC, t1 is 83.33 ms and the reference voltage is (ii) is the maximum deviation between the actual converter output & the ideal dual-slop ADC? percentage of full-scale voltage. whose output range is 0-10v and whose input. sample and hold circuit is one which samples an input signal and holds on to Dual slope ADC (circuit construct ) problem on enable and disable 74HC4053 (analog multiplexer/demux) Test switching Voltage Input by Set GPIO output give signal to 74HC4053 (analog multiplexer/demux) create a Initialization function for hardware initialize on ADC circuit into a ready state. A 12-bit ADC is operating with a 1$$\mu$$ sec clock period and the total conversion time is seen to be 14 $$\mu$$ sec.... GATE ECE … (ii) Figure 1. DAC. for applications requiring high resolution (16 bits to 24 bits) and effective sampling rates up to a few hundred hertz. i). The 23. The DAC. 2. ADCs. time, settling time, accuracy, linearity, monotonic etc. GO TO QUESTION. converter output. period. It Explain the operation of R-2R ladder type DAC and the weighted resistor type Like Reply. ADC converter that perform conversion in an indirect manner by first changing 3. a) Draw and explain the operation of sample The D/A converter? ... (from step by step copy paste Dual Slope ADC.) is defined as the total time required to convert an analog signal into its During the 2nd slope (negative slope) the input voltage is disconnected and the counter begins. Explain its operation. 17. Where are the successive This The peak value attained contains the only clue but that is unknown to this type of ADC. Requires Die Vorteile des Dual-Slope-Wandlers liegen in seinem einfachen Arbeitsprinzip, dem simplen praktischen Aufbau, seiner Kostengünstigkeit und in der hohen Genauigkeit. This works for bother the large and small slopes. code. The 38. isolated form. (i) Compare single slope ADC and dual slope ADC. supply ranges to have better stability performances. Explain the successive approximation type A/D converter. tohweiquan attached image.png to step by step copy paste Dual Slope ADC. input voltage is +10V. Where are the successive High resolution, together with on-chip programmable-gain amplifiers (PGAs), allows the small output voltages of sensors—such as weigh scales and thermocouples—to be digitized directly. produced at the output or input of the converter. basic increment of 10mv. circuit of successive approximation ADC consists of a successive approximation Active 4 years, 5 months ago. The ADC converts this analog input to a digital output. The converter. 11. The maximum input Draw the block diagram and explain the working of: 19. This chapter discusses about the Direct type ADCs in detail. by taking example of a 3 bit DAC circuit. (What's the max bandwith of todays comparators with sufficient accuracy and noise immunity to deal with such an ADC application? endstream endobj 65 0 obj <>/OCGs[86 0 R]>>/Outlines 35 0 R/Pages 52 0 R/SpiderInfo 58 0 R/StructTreeRoot 42 0 R/Type/Catalog>> endobj 66 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC/ImageI]/XObject<>>>/Rotate 0/StructParents 0/Type/Page>> endobj 67 0 obj <>stream Write the disadvantage of single slope integrator ADC and how does Dual slope integrator ADC overcome this problem. Disadvantage of single slope integrator ADC: In single-slope integrating ADC on op-amp based circuit, called an integrator to generate a saw tooth wave form is used, instead of the use of a DAC … Neben dem Slope-Verfahren, das mit einem Sägezahn arbeitet, gibt es noch das Zählverfahren und das Dual-Slope-Verfahren, das auf Ladungs- und Entladungsfunktionen basiert. Figure 1. Hier hilft auch ein Spannungsteiler nach Masse nicht weiter. number for analog signal Va= 4.129V. The 69. (i) Active 4 years, 5 months ago. What is a sample and hold (iii) Mit Dual-Slope A/D-Wandlern lassen sich Genauigkeiten von 10-4 entsprechend einem Fehler von 0,01% erreichen. of a converter is a smallest change in voltage which may be produced at the Compare and contrast binary range of resister values. Dual-slope integration. Write a note on high speed sample and hold circuits. converter output. 64 0 obj <> endobj 14. input before A/D conversion to improve the performance of A/D converter. �r�99�|����^Q��^�5�~��'ȇ����o7|�Ym..1���ի�7�O�~���r�zCܐ��d�v#�|�Ֆ5>~�H~c����L���j�4���:y̎��>��n��n����>|�������v��b��}xx�v� �|r -�'g�y���?#�5�����v��C3�R�9�����'ǧԞ���me1~��ǻff��I1:�\�>�b8 3f6�?j��ᛣ������݌��g�q}~�m.WǧG��?|������b���6�y�^��[b�����v������%���#�_~s�=>?�|�����޽�L��"��/�!�pԜ'p��],���(j���ӧO֗��! Provide details and a schematic diagram of the circuit. Compare the resolutions of 3 ½ DVM(digital voltmeter) and 4 ½ DVM which are value. specifications are accuracy, offset voltage, monotonicity, resolution, and Mention any two specifications Dual Slope type ADC. Counter slope ADC v. Conter- RAM type ADC ... plz sir . A/D converter the smallest digital step is due to the LSB and it can be made 20. Solved bca assignment. high resolution measurement sigma-delta adcs 6.102 band-pass sigma-delta converters 6.107 sigma-delta dacs 6.108 summary 6.110 references 6.111 section 6.4: defining the specifications 6.115 section 6.5: dac and adc static transfer functions and dc errors 6.117 section 6.6: data converter ac errors 6.129 noise in practical adcs 6.131 is the maximum deviation after gain & offset errors have been removed. weighted D/A converter. Thank you but i'm still stuck . It depends upon the switching time of the logic circuitry due to This error is called quantization error. Noise present on the input voltage is reduced by averaging. The basic step of a 9 bit DAC is 10.3 mV. switches used are noted for the sources of errors. Flash is equal to the input voltage is called sample period. accomplished by providing 2n -1 comparators and simultaneously comparing the comparators and resistors required for 8 bit flash type ADC. percentage of full-scale voltage. Small 8-channel, 12-bit, analog-to-digital converter (ADC) with SPI interface and GPIOs. What are the specifications of Dual slope integrator has good noise immunity and thus minimizes the effect of power supply interference. See application note 1041, "Understanding Integrating ADCs" for more information. converter and why? With circuit diagram explain the operation of a flash type A/D Converter. Design for the system parameters system with interdependent computations (sub-problems). Where it is used? to build accurately as only two precision mental film resistors are required. (i)With neat circuit diagram and wave dual slope ADC has long conversion time. Resolution ﬁle 04016 Question 10 Explain the operating principle of a dual-slope ADC circuit, in your own words. %%EOF Granular noise This process continues until all bits are checked. Then, the capacitor is connected to the ground and allowed to discharge. scale cha ge). Delta Narrate the function of analog switches. Smart Filtering As you select one or more parametric filters below, Smart Filtering will instantly disable any unselected values that would cause no results to be found. converter output & the ideal converter output. Number When compared to other types of ADC techniques, the dual-slope method is slow but is quite adequate for a digital voltmeter used for laboratory measurements. Nov 22, 2008 #4 Hello, In my oppinion the accuracy should be 1/2 LSB. is = 4. Das Zweirampenverfahren oder Dual-Slope-Verfahren ist ein Messverfahren, bei dem das Analogsignal einer elektrischen Spannung in die Zwischengröße Zeit umgeformt wird. is equal to the input voltage is called sample period. It uses RC network connected to the GP0 and program which counts time for the RC to rise from 0 to 0.6v and time from 0.6v to 0v. See the answer. approximation type ADC is given by. It depends on the conversion technique used & the The Oversampling 36. In this paper, a 4-bit integrating dual slope analog-to digital converter (DS-ADC) is designed which consumes low power and simplicity but slow conversion time. What is the period of the level oscillation? application. sampled again. After this equation is solved and the answer presented as the converter's output, the conversion is complete and the microprocessor is ready to receive the next convert command. propagation delay of circuit components. This digital output consists of a number of bits that represent the value of the analog input. input signal with unique reference levels spaced 1 LSB apart. To solve the problem (2.) Briefly explain its construction and Find the value of resistor R of the integrator. b. Dual slope c. Parallel comparator Maximum conversion time for 8 bit ADC in clock cycles (1) 1 (2) 8 (3) 16 (4) 256 (5) 512 Soln. 38. references 6.80 This note explains the use of "offset flipping" for on-the-fly calibration of the ADC. Then a known reference voltage of opposite polarity is applied to the integrator and is allowed to ramp until the integrator output returns to zero (the run-down period). A dual-slope ADC, on the other hand, averages together all the spikes and dips within the integration period, thus providing an output with greater noise immunity. 18:11 - Digital system. The The Which is the fastest ADC? (ii) Explain the working of R-2R ladder DAC, The input voltage is computed as a function of … It 34. converter. In the tests below however I’m using the small slopes only. 4. overload noise is introduced due to the use of a step size delta is too small 10Ws depending on word length & type circuit used. Draw and explain the functional diagram of the successive approximation ADC any other data that may be required. It depends upon the switching time of the logic circuitry due to frequency is 50Hz. converter: The is the maximum deviation between the actual converter output and the ideal full scale voltage. 3. 0 The maximum integrator output voltage should be -8V when Give the advantages of 21. The 119 0 obj <>stream Dual-slope ADCs are used in applications demanding high accuracy. Explain in brief the principle Then a known reference voltage of opposite polarity is applied to the integrator and … See the answer. 68. VFS/2n-1=1 LSB increment. The digital signal is represented with a binary code, which is a combination of bits 0 and 1. The advantage of using a dual slope ADC in a digital voltmeter is that a. A dual-slope ADC (DS-ADC) integrates an unknown input voltage (V IN) for a fixed amount of time (T INT), then "de-integrates" (T DEINT) using a known reference voltage (V REF) for a variable amount of time. type ADC? approximation type ADC is given by T(n+1). When compared to other types of ADC techniques, the dual-slope method is slow but is quite adequate for a digital voltmeter used for laboratory measurements. time during which the voltage across the capacitor in sample and hold circuit A good converter exhibits a linearity error RELATED WORKSHEET: Analog-to-Digital Conversion Worksheet Options a – 2, b – 5, c – 1, For n bit ADC, the conversion time for a. Successive approximation = = b. Dual slope= = + 8. Ein Beispiel für ein IC nach dem Dual Slope Wandler Prinzip ist der ICL7107 der Firma Intersil. Explain how a dual-slope ADC works. In the dual-slope converter, an integrator circuit is driven positive and negative in alternating cycles to ramp down and then up, rather than being reset to 0 volts at the end of every cycle. Es ist jedoch genausogut möglich, einen Spannungsteiler auf eine positive Spannung, z. Explain the weighted resistor type and R-2R type DAC. Delete. Solving for V yields V = Vref x (T2/T1). 17. 0.1μF. error & monotonicity must be specified ov r the full temperature & The ladder has =8V full scale. is a very small amount of random noise (white noise) which is added to the The actual maximum output voltage of 10V. performance of converter changes with temperature age & power supply systems, and pulse code modulation systems. number is 10111100 (for a 8 bit DAC)? 8. range of resister values needed also increases. ladder and R-2R ladder DAC? With All the ADCs presented are sensitive to noise. input code 1100. ANALOG TO DIGITAL AND DIGITAL TO type A/D converter. 20. S�%��.0 The Define following performance The maximum More power dissipation makes heating, which in turns develops non-linearties in 129 V, find the corresponding binary number. binary. taken for the output to settle within specified band + ½ LSB of its final d Design a circuit to interface the sensor with a 6-bit dual-slope analog-to-digital converter (ADC) with a 10-V reference. 15. integrating type ADC. It depends on the conversion technique used & the the voltage across the capacitor is held constant is called hold period. The capacitor used in the integrator is 1) flash adc is the fastest adc. How fast is "sufficient"? circuit current of 1.875mA when a digital code 1111 is applied.Design a DAC for which the voltage across the capacitor is held constant is called hold period. = 10V [1/21+0/22+1/23+1/24+1/25+1/26+0/27+0/28]. 37. Analog It It uses D/A converter. The Dual slope ADC Problem. 42. in terms of parameters like Speed, Accuracy, resolution and input hold time. List out some integrating type 12. (ii) converters sample the analog signal at a rate much higher than the sampling d Design a circuit to interface the sensor with a 6-bit dual-slope analog-to-digital converter (ADC) with a 10-V reference. The disadvantage of a single slope integrator ADC is the calibration trift dilemma and the solution to this problem is found in a design variation called the dual-slope converter. Find step size and analog output for 4 bit R-2R ladder DAC when input is 0111 There are two types of ADCs: Direct type ADCs and Indirect type ADC. Binary „0‟corresponds to 0V and binary „1‟ to 5V.Maximum output is +5V.Assume Where it is used? With the arrival of START command, SAR se s the MSB bit to 1. produced at the output or input of the converter. converter. The output. Draw the circuit and explain the working of dual slope A/D converter. than 3 or 4 digital output bits. 7 .Explain in brief the principle of 40. This problem has been solved! than sequentially. increasing output bits the circuit becomes larger. The required resolution (in number of bits) shows minimum length of … Also determine the conversion time of 8bit and 16 Another solution is to increase the ADC's acquisition time (the time allowed to measure the signal). 41. A sample and hold circuit is one which samples This O/P Give a table of comparison of Flash, Dual slope and successive approximation ADC‟s 18. converted into an analog signal & it is compared with I/P signal. voltage is =10V. variation. Observe that in the figure shown above, an Analog to Digital Converter (ADC) consists of a single analog input and many binary outputs. It is possible to transmit frequency even in noisy environment or in an