Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
the negative feedback is when u connect the feedback resistor between output and inbverting input terminal...positive feedback is just the opposite...u connect the feedback resistor between output and noninbverting input terminal.....
heyy this is really a bit confusing.Let's me try..Whenever u use an op-amp as a amplifier(Liner-region) u always use a negative feedback.While using a op-amp as a comparator takes positive feedback.so don't be confuse both inverting and non-inverting amplifier use negative feedbacks.
thanks.
I am very sorry let me make my question clear ofcourse there is negative feedback in both the configaration but what kind of negative feedback viz voltage series or current series and so on..... i just wanted to know what is sampled at the o/p(current or voltage) and what is mixed at the i/p........
u can just apply two tricks and u will get the answer
Short the output pin and see whether the feedback is zero and similarly try open circuit and check the feedback.If its zero in short circuit case then its voltage and in open circuit case its current. Apply the same trick at input side and see whether the voltage or current becomes zero or not at the input side.If ur unable to make it.Let me know I will tell u the answer.
barath_87,
In the inverting configuration, you are feeding back a current that is proportional to the voltage output. The feedback current sums with the current thru the input resistor to get a result of zero input current to the inverting input to the op-amd.
.
In the non-inverting configuration, you are feeadg back a voltage to the inverting input that is proportional to the output voltage. The output reaches equilibrium when the fed-back inverting input voltage equals the voltage on the non-inverting input.
.
In both cases, I have ignored the effects of offset voltage, offset current, bias current and common mode errors.
Regards,
Kral
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.