Switched-Capacitor Amplifier Design: How does it work?

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7 ай бұрын

How to design a Switched Capacitor Amplifier and how does it work are discussed in this circuit tutorial video that uses examples of inverting and non-inverting op amp amplifiers to answer these questions. For more op amp and analog circuit examples see • Electrical Engineering... . This switched capacitor circuit is implemented with one operational amplifier, two capacitors and five NMOS transistors or N-channel MOSFETs as switches with their gate voltages controlled properly by one of the two non-overlapping clocks in the circuit. The switched-capacitor circuit is effectively a sample and hold operation for the output input and output voltages. The circuit effectively emulates two large equivalent resistors on the order of as high as multi Mega Ohm resistance values. These large resistors are not practically realizable on-chip due to their excessive and expensive silicon footprint and also accompanied non-idealities including parasitic undesired capacitance and inductance and considerable 20-50% variations due to variety of factors including silicon chip manufacturing process, IR-drop, temperature variations. On the other hand, if carefully designed, the switched-capacitor amplifier can achieve the same target performance and gain with orders of magnitude smaller on-chip silicon foot-print and considerably less gain variations (as low as 0.1% for the gain as the ratio of capacitors involved in a proper switched-cap circuit design). A combination of Op Amp virtual short (Op Amp biased properly with negative feedback) and Kirchhoff Circuit Laws including KCL, KVL is applied to present the analysis and compute the gain of the designed switched-capacitor amplifier.

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@STEMprof 7 ай бұрын

Thanks for watching. For more Op Amp Circuits please see: Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Differential Amplifier Design with BJT transistors kzfaq.info/get/bejne/sLGXhryn0J2ucYE.html Power Amplifier Design (Class A) with Transformer kzfaq.info/get/bejne/nbGcfdWirNfJc30.html Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html Sallen-Key Analog Filter Design Tutorial kzfaq.info/get/bejne/gd2FobSJx9Gbl4E.html How to find Bode Plot, Freq Response, Transfer Function of Analog Filters kzfaq.info/get/bejne/rMB2nrOWqceVeGw.html Universal Analog Filter Design kzfaq.info/get/bejne/aLBdY9CkvcCpYqM.html Laplace Transform Example and S-domain circuit analysis: kzfaq.info/get/bejne/ptlogZiFtbPDoYk.html Op Amp circuit Bode Frequency plot kzfaq.info/get/bejne/eLKGrdim1qfQiqc.html Lowpass Butterworth Filter: kzfaq.info/get/bejne/i-Bznc6o1t-Raas.html Analog Computer to Raise Signal to power n kzfaq.info/get/bejne/f7uEn6V5lrvWkXk.html Differential Equation Solver Analog Circuit kzfaq.info/get/bejne/iJmIaKSKs8CrdX0.html Complex Sinusoid Oscillator kzfaq.info/get/bejne/fb6Cm9Co0rmZip8.html Full-Wave Rectifier circuit example kzfaq.info/get/bejne/erB6gLGGkqm9k5s.html Sawtooth Waveform Generator design with OpAmp, JFET, BJT kzfaq.info/get/bejne/a-B4i7epkrzQYmQ.html op amps Circuit with feedback loops to design an analog computer that solves a second order differential equation kzfaq.info/get/bejne/fsuKhdeft77UdX0.html For more analog circuits and signal processing examples see: kzfaq.info/sun/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt I hope these Circuit design and analysis videos are helpful. 🙂

@souravnandi6162 2 ай бұрын

Wonderful explanation sir

@STEMprof 2 ай бұрын

Thank you! Glad that you liked this switched-cap video. Here are a few related videos: Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Amplifier kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html I hope these Circuit videos are interesting 🙋‍♂️

@AjinkyaMahajan 7 ай бұрын

Thanks for the wonderful explanation. I was searching for SC content from long time. Cheers!!

@STEMprof 7 ай бұрын

You're welcome! Thanks for watching. Glad that this switched-capacitor amplifier tutorial is useful. For more circuits please see: Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html I hope these Circuit Analysis videos are interesting 🙂

@estebeer 27 күн бұрын

C2 also works as an offset compensation of the opamp

@STEMprof 23 күн бұрын

Good point! Thanks for your interest and for sharing your insights.

@sahryun 6 ай бұрын

Nice and well-understood.

@STEMprof 6 ай бұрын

Thank you for watching. Glad that this switched capacitor amplifier design tutorial is useful. For more circuits please see: Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html I hope these Circuit videos are interesting 🙂

@Chupacabras222 7 ай бұрын

Very interesting. What's the switching noise? Is the output usually filtered somehow?

@STEMprof 7 ай бұрын

Thanks for watching and your comment. Glad that you like this switched-capacitor amplifier design video. To your point, switching noise and clock non-idealities are important practical considerations in switched-cap circuit design. I'll post more examples in the analog playlist below. Examples of such non-idealities are flicker and shot noise, parasitic capacitance and charge sharing between the switches and circuit nodes, clock feedthrough, charge injection, clock Jitter, Skew, drift etc. Depending on circuit type and target design KPIs, there are number of noise reduction techniques for switched-capacitor circuits to reduce or compensate clock/switch non-idealities. Examples of such techniques include use larger capacitors, higher clock frequencies (oversampling), better matched transistors, noise shaping, noise modulation using Delta-sigma modulation, or filter noise by using proper filters in either the continuous or discrete-time domain. These are extensive topics that require dedicated examples and video. For more analog circuit examples please see: Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html kzfaq.info/sun/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt I hope this is helpful. 🙂

@nafiuranik7598 2 ай бұрын

How can i simulate this circuit in proteus can u give me the all components name sir kindly?

@STEMprof 2 ай бұрын

@nafiuranik7598 Glad that you found this switch cap amplifier circuit tutorial useful. In depends what applications you are targeting. If it is Audio Signal Processing, then Your frequency range of interest is between 50 Hz to 20 kHz. So I suggest you select your clock frequency conservatively between 200 to 400 KHz. Then, given the clock frequency is not high, conservatively select an Op Amp that has a slew rate 20 times faster than your clock frequency. For example, if your clock rate is 400 kHz, then select Op Amp with slew rate of roughly peak-peak V (say 5 volts) per 100 ns or faster. Your NMOS transistors should also be comfortably able to work at few MHz rate. More op amp amplifier examples and videos are posted in kzfaq.info/sun/PLrwXF7N522y5679YAO-lFrNVYqV9XMNTr playlist. I hope this is helpful.

@nafiuranik7598 Ай бұрын

@@STEMprofhow can i use switch capacitor common mode circuit to mitigate its noise?

@sc0or 6 ай бұрын

We can divide an output signal by 100 and then use 20k resistor to get an overall gain of 200. So, we will have 10k, 20k, 100, and 10K, and no problem with a space on a chip (and a thermal noise) I think

@STEMprof 6 ай бұрын

Thanks for watching and your interest in this switched capacitor amplifier example. Dividing a signal is not a good practice in general due to noise issues. Also, beyond this example, there are circuit/filter design cases in which 100+ kOhm or Mega Ohm resistors are needed on-chip and those can mainly be realized using switched capacitor techniques. For more circuits please see: Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Differential Amplifier Design with BJT transistors kzfaq.info/get/bejne/sLGXhryn0J2ucYE.html Power Amplifier Design (Class A) with Transformer kzfaq.info/get/bejne/nbGcfdWirNfJc30.html Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html I hope these Circuit Analysis videos are interesting as well 🙂

@davidlavasani8637 7 ай бұрын

Are you persian? 🤔

@STEMprof 7 ай бұрын

Thanks David for watching & your interest. For more Analog circuits please see: Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html I hope these Circuit videos are interesting 🙋‍♂️

@AnotherPointOfView944 7 ай бұрын

talking too fast

@STEMprof 7 ай бұрын

Thanks for watching & feedback. I'll post more switched capacitor examples. For more circuits please see Op Amp Analog Computer Differential Equation Solver kzfaq.info/get/bejne/e7ShZpx2ytnKgKs.html Instrumentation Amplifier with Electronic Gain Control kzfaq.info/get/bejne/eZqkmsuLkteaiqc.html Thermometer Circuit Design with Op Amp & BJT transistor kzfaq.info/get/bejne/a5uJptWSq6uUops.html Push-Pull Power Amplifier with Darlington Transistors kzfaq.info/get/bejne/bpxmgLyax9WcqXk.html Analog Logarithm Computer kzfaq.info/get/bejne/iNZ7eNRmvN_TfJs.html Sawtooth Oscillator Design kzfaq.info/get/bejne/aMuFpqqBy9fGh2g.html Triangle Oscillator Op Amp circuit kzfaq.info/get/bejne/gKxliNOQyNuwaZ8.html I hope these Circuit Analysis videos are helpful. 🙂