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.
Th 741 will not have the bandwidth to output a decent square wave at 40khz - as you have found out. I discovered the same thing in a school project years ago. We switched to a hotter opamp and the project worked like a charm. I forget which opamp we switched to but there are numerous available that are pin compatible to the 741.
try visiting this page and select the required opamp by going through the datasheets... if you post the circuit you are using we would be able to know what your requirement is.... because we dont know the source of your input and what your output is gonna drive...
i'm using PIC16F877A to generate pulse 40kHz in order to send to transducer for distance measurement, output from PIC16F877A is 40kHz 5Vpp square wave, so i need to amplifier the signal become 20Vpp in order to operate my system.
from the webench, i don't not how the requirement come from, with Vmin=0 and Vmax=5 then signal frequency 40kHz and supply +/-12v, but why it said wrong value and cant build
and the collector buffer seem like complecated, i'm not so understand how it work
The open collector buffer is an inverter with the open collector at the output. Attach, say a 10K resistor from the output pin to 20V and that is all you need to do. To keep your signal polarity the same as the input (not inverted) place an inverter before the open collector one (inverting twice).
Less complicated than an op-amp. In fact, an op amp is not the correct way of performing the task you are trying to.