Questions tagged [slew-rate]

Anything related to slew rate (SR in datasheets), i.e. a characteristic parameter of analog amplifier circuits (notably operational amplifiers). The slew rate of an amplifier is the maximum rate of variation that the input signal can exhibit in order for the output amplified signal to follow it without distortion.

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77 views

Question about the slew rate

Let's consider an op-amp: From basic courses of electronics, we know that the output voltage as a function of the differential input is given by the following picture: Now, assuming that: the op-...
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Calculation of the slew rate of a two-stages op-amp

Let's consider the following two-stages op-amp: I have difficulties in understanding how the author of my book calculates the slew rate of this op-amp. The book says: Question 1: Why should the ...
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CA3140 wideband output amplifier

The following circuit is nearly exactly what I need for the output stage of my function generator: datasheet: https://www.renesas.com/us/en/www/doc/datasheet/ca3140-a.pdf What I don't understand is ...
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Calculation of the slew rate of an inverter with active load

I'm studying the inverter with active load, whose scheme is the following: Now, the author of my book says: "We have to ensure a proper large-signal driving of the output node. The load of the ...
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32 views

Limit in-rush current for DCDC

We are using a Isolated Fixed-Ratio DC-DC Converter from Vicor (http://www.vicorpower.com/documents/datasheets/ds_BCM4414xG0F4440yzz.pdf) that is powered through a 600VDC accumulator. The DCDC powers ...
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31 views

Howland source for adjusting slew

I am using a Howland current source and sink in the above circuit for adjusting slew rate, however I am not getting desired results. simulate this circuit – Schematic created using CircuitLab
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55 views

Inverting OP AMP SLEW RATE

I'm trying to do a question that requires me to design an inverting op-amp in multisim and find the slew rates in different scenarios using the OPAMP_5T_VIRTUAL operational amplifier model found in ...
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67 views

Communication between device for 5 meters and low speeds

I need to make a communication between only two devices with a distance of 5 meters, which are connected by a cable of 4x2.5mm² (see in the image), being 1 wire for GND and wire for 12v, that would ...
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Why is SLEW RATE in nMOS amplifiers worst when the output is going from LOW to HIGH?

And, of course, why in pMOS amps the SR is worst in the other case (output going from HIGH to LOW).
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Can an amplifier slew rate be used as a low pass anti-aliasing filter?

A slew rate calculator says that for an arbitrary 100MHz signal a minimum slew rate of 1884V/μS is required. If I used an amplifier with that exact slew rate is it also a low pass filter? It seems ...
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51 views

Will the DC offset of signal affect the slew rate in an op amp?

I'm curious if the DC offset of a signal going into an op amp will affect the slew rate. Lets say you have an op amp configured to drive a 150 Ω load and is spec'ed to provided an output swing of ±3 ...
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Buffer requirements for S/H circuits

I am trying to solve question 11.10 which is taken from 2001 GATE IN paper. So I think the answer is (a) because the input buffer which faces the analog input needs a higher slew rate in order to ...
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Slew Rate related EMI: How relevant is it for motor control circuits ?

I am designing a 3-phase inverter board for BLDC Motor control. The H-bridges i use are IFX007 from Infineon. The mentioned IC has the possibility to adjust the slew rate. From what i have read, i've ...
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Operational amplifier for higher slew rate

what are the possible ways to improve slew rate of an operational amplifier in CMOS technology?
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115 views

H-Bridge Adjustable Slew Rate: Why is a decoupling capacitor needed?

I am designing a simple 3-phase inverter for BLDC Motor control. For that purpose, i plan to use a IFX007T from Infineon. The slew rate is controlled via a resistance connected in series to SR pin. ...
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64 views

Constant DC Load Stability and Bandwidth slewrate

For this circuit, how do I know if the rise edge was limited by slew rate or bandwidth? What's the effect of R2 and C2 on bandwidth? -3db of this circuit in simulation is 649 kHz, I know in ...
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Why does the op amp output in this circuit have low slew rate?

I have the following circuit on a bread board (with the exception of using AD820 instead of AD822 - the main difference based on the datasheets seemed to be one versus two op amps in one package). ...
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265 views

How do I decrease the slew rate of an op amp?

I need to reduce the slew rate of a voltage follower, so that if I change the input signal from 0 to 5 v, the output signal will rise progressively up to 5 v in say, about 5 seconds, so a slew rate of ...
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Slew Rate controlled MOSFET switch

This circuit controls the rate at which M1 switches on using the current mirror consisting of Q1 and Q2. A digital pot is used to control the current through Q2. The circuit works great in simulation, ...
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209 views

Question regarding slew-rate

I have a question regarding SR effect. Let's say that we have some simple amplifier with op-amp with the following parameters: \$G=+10 \ V/V, \ f_c=1MHz, \ SR =1V/\mu s, \ V_{supply}=\pm 15V\$ ...
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Slew Rate Adjustability

A SPST switch connects HB1 and HB2, to control a lamp connected to HB OUT. I am looking into modifying this circuit to make the slew rate adjustable when switching the output to VCC (around 12V). I ...
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If there exists a cascade of op amps, does the previous op amp's slew rate affect the later op amp's slew rates?

All op amps used are the same Texas Instrument LM348n. The datasheet says the op amp has a nominal slew rate of 0.5 V/µs, but gives no tolerance. I have a square signal with an amplitude of 500 mV ...
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Logic gate directly driving power MOSFET

Art of Electronics, 3rd Ed, pg. 164-165 give an example of naively using a 4000-series CMOS logic gate to directly switch a power MOSFET, disregarding the significant gate current required to charge ...
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How the slew-rate and drive strength affect the output signal of the FPGA?

Can someone describe the difference between the drive strength and the slew-rate preferences in Lattice FPGA?
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94 views

SlewRate and Output Swing for a differential OpAmp [closed]

I want to calculate SR and output swing for a fully differential OpAmp, using simulation. I came across this solution for a single-ended OpAmp: A. SR calculation: B. swing - make 'Vin' in the above ...
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651 views

Calculating Slew Rate from a time-constant

I have to choose an OP-AMP mainly based on slew rate. I am using the op-amp as a differential comparator with dynamic (time) hysteresis with a time-constant 3*tau=500µs. My upper threshold of the ...
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436 views

OpAmp Design Questions for Transimpedance Amplifier

I'm trying to improve on a transimpedance amplifier design by changing out the op-amp that I'm currently using for another one. The issue I'm facing now is that I'm unsure as to how to pick a good op-...
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642 views

Slew Rate and Bandwidth of Transistor Amplifier

How can I calculate the slew rate and bandwidth of a typical transistor amplifier such as the following? What are the parameters I need to consider? simulate this circuit – Schematic created ...
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202 views

Slew Rate Controlled GPIO

What is the purpose or advantage of using Slew Rate controlled output capability for GPIOs?
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Why is opamp slew rate specified at unity gain?

Is there some reason besides convention to add the "at unity gain" qualifier? Does adding or omitting it communicate something about the component? Are the opamps which have a slew rate that varies ...
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101 views

Op Amp IC slew rate discrepancy

I have been trying to understand slew rate and so I set up a circuit with an op amp (LM741) that would allow me to measure it. The claimed slew rate of the package is about 0.50V/us, but my slew rate ...
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Step response of power load switches

Many load switches implement a fix or controlled slew-rate of its output current in order to prevent inrush currents. I was wondering what is the step response of this kind of switches after the slew-...
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Optimizing op-amp overload recovery behaviour

I'm measuring a thermocouple which connected series with a heating element. Heater is driven with PWM and when PWM is off-duty, a measurement is taken through output A0 using an ADC. Relevant parts ...
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140 views

Slew rate limiting of bidirectional lines

Assuming the ICs in use don't offer an adjustable slew rate, if I want to limit the slew rate of a unidirectional digital data line, for example of SPI's MOSI-signal, I can put a series resistor at ...
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169 views

Op-Amp Slew Rate

I've been searching for a very-small package op-amp and not having much luck. LTxxxxxx (edited out) would be ideal however the slew rate is just too low. Is there a way of controlling/increasing slew ...
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307 views

Slew rate's effect on output waveform

I was asked to draw over the given graph in this question the output resulting from the SR. Could it be something like this?
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313 views

Circuit to limit negative (falling) slew rate only

I am in search for a way to only limit the negative slew rate while leaving rising parts of the signal untouched. The signal will be anything from Subaudio till 20kHz, with potentially arbitrary ...
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Amplifying a PWM signal with an op amp. Is the slew rate a problem?

I need to amplify a PWM signal from 5V to 24V in order to drive a mosfet that in turn drives a small DC motor. The input signal has a frequency of 500Hz and comes from Arduino uno (pin 9). For ...
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605 views

Importance of slew rate?

I am going to choose an op-amp as a buffer for my pH sensor. How much slew rate of an op-amp is important in choosing my op-amp? The slew rate of op-amp that I search range from 0.02 V/µs to 12&...
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987 views

Are slew rate frequency and cut off frequency same?

I am bit confused about the cut off frequency and the max frequency above which the output response starts to distort which is slew rate frequency. Are these two things same? Cutoff frequency (f) = ...
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slew rate of a mosfet

Is there way to calculate slew rate of following circuit? simulate this circuit – Schematic created using CircuitLab Datasheet for Transistor Datasheet for Diode I chose the PMOS and Diode ...
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519 views

Differential input voltage necessary for maximum slew rate in operational amplifiers

Today I ran into a problem with op-amp slew rate when playing with a design where an op-amp spends a lot of time in saturation, only to occasionally "come down" and regulate the output. (I'm ...
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452 views

Virtual ground in two-stage OpAmp for slew rate calculation

I am reading about slew rate of two-stage OpAmp from this page. However, I don't understand why the node voltage at drain of M2 or M4 is assumed to be a virtual ground here. Could anyone explain ...
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529 views

Improving RS485 / UART slew rates

I'm trying to implement a half-duplex 1Mbps RS485 bus (1 master controlling ~8 motors). After facing occasional communication errors I've invested in a Saleae logic 4. The RS485 A/B lines probed ...
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How can I create a microphone preamp with a variable slew rate? [closed]

How can I create a microphone preamp with a variable slew rate that is dialed in with a button and have a wide range from very slow to very fast?
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1answer
761 views

BJT sample and hold circuit for 50 MHz clock

I've designed a sample and hold circuit (as shown in the snapshot of the circuit attached) but i'm having slew rate problems, if I try to adjust the slew rate (by adjusting the capapacitor and ...
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78 views

Operational Amplificator Association effect on Slew Rate

I am designing a circuit which means getting sinusoidal signal as as Input and pass it to an ADC. Since the ADC supports tensions from 0V to 5V and my input 5Vpp, then I need to escalate it properly (...
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Does slew rate depend on frequency of input signal?

I am just beginning to study analog integrated design. Say I've designed a two stage operational amplifier with compensation. The slew rate would is given by: $$\text{SR} = I_{\text{sat}}/C$$ For a ...
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Slow slew-rate of photodiode circuit output

I've built an LED driver and a photodetecting circuit. Basic forms of the driver and the detector were made. Driver Detector FYI: Parts used and their datasheets LED: Seoul semiconductor W42182 (...
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Precharging capacitors with P mosfet slew rate control - Unwanted turn ON

I am considering using a MOSFET to control the dV/dt rise (slew rate) when power is first applied to a DCDC power supply. This will hopefully resolve both a precharging issue I am having and the ...