diff --git a/README.md b/README.md index af8e6f7..2154fc8 100644 --- a/README.md +++ b/README.md @@ -1,5 +1,5 @@ # Op-Amp AC amplifier with highpass and lowpass filters -* For use with MCP6001 or similar amplifier +* For use with [MCP6001](https://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf) or similar amplifier * Works with mV inputs centered around GND * Few components, 0603 passives for easy soldering @@ -39,18 +39,25 @@ Note! The MCP6001 has a GBW of 1MHz. This means, if the gain is set to 100x, the * Gain = R2/R1 + 1 * Gain is limited by the GBW (gain-bandwidth product) of the op-amp used * MCP6001 has a GBW of 1MHz, so max frequency = 1MHz / gain (3db loss at that frequency) +* If you need higher frequencies / more gain, you can use a different op-amp, like an LMV721 ## C2 makes the output centered around the biasing frequency * Whatever voltage Rb+ and Rb- form, will be the center frequency of the output * In essance, the gain for DC is 0 (since the gain resistors R1 and R2 have not DC path to GND) * C2 just needs to be big enough, when it is big enough it does not affect filtering -## Rlp and Cout can be used for an output lowpass +## Rout and Clp can be used for an output lowpass * Classic low pass filter, nothing to see here -## Rlp and Cout can instead be used for an output highpass +## Rout and Clp can instead be used for an output highpass * Just swap the position of the capacitor and resistor. It's ok, they fit. +## Cbypass must be between 100nF and 1uF +* This is to ensure stable operation of the op-amp + +## An additional bypass near the VCC / GND pins of the header +* An additional bypass capacitor may be placed there, if necessary + # Soldering tips ![Soldered board](images/soldered.jpg) @@ -64,4 +71,4 @@ Note! The MCP6001 has a GBW of 1MHz. This means, if the gain is set to 100x, the # Simulation ![Simulation](images/simulation.png) -[Falstad simulation available here (https://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3BWEDYCYDMqDsrUE4AOLSAgsJANiSQBZ1kBTAWjDACgBDEXG8CyEOnQU+AvMijh48btAR48WAnnQIMqGpAR1Z8wnHR5IRinSxTpbAO7cN4GrzwiwDqGwBOIJ-cciCAgXJ4Dy9nV29UEkkguDYAY1CfPiTeGGlICFRoGgV-BCxVBTAcIihYDLcAc0TIghq7ALYAJUT-RJo6gJBNCS6YBGtbXmKRHiG3TzGxoVGGi1ibGfGlsH4J8bHVgTHA4IStwUjRbgQRVPL4BSvrm4UQJiyclQINCnQS9EhzuAhINmqDphAmslo1FsJjsI6gc-p4occ6Khjrs-glEQjMONhswwEj0NB+OgCAgCMIEFoaBpFGUflVupixujUKdJH8AB73KjIXgUJFKbrgOoASQAdgAHACuABcADoAZwAFgBLSoKsUcOVymUykUcEUAE3lACMlRr5XEAPYAWyNFrYHNwSE+Akw5k+9GGdQAglaxQAbJUAMyVcQ4UqVFpF9qk5jAkHoYAhcbOgpATSNTGjrGBsZ0xQEnrTRplYujefIIGI4DAdULAGElVGHRRxFTuHgkcykYWmuwOTXO2puFoTrRU01UIMDps1syROzwFg3cVhy6jvXJxyicMVzQl+B16mAPLSyWyuXBv1ShjuQbog4dYGNDk5WPyZDoYa8gU1kBHgCqAAqbD5skLi8EwphJEi5IgP4cBlL8aBsBa3DmEiBbGOIWDQGAeAdDg2D5AQvLYDStKBGwQA)] \ No newline at end of file +[Falstad simulation available here CLICK CLICK](https://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3BWEDYCYDMqDsrUE4AOLSAgsJANiSQBZ1kBTAWjDACgBDEXG8CyEOnQU+AvMijh48btAR48WAnnQIMqGpAR1Z8wnHR5IRinSxTpbAO7cN4GrzwiwDqGwBOIJ-cciCAgXJ4Dy9nV29UEkkguDYAY1CfPiTeGGlICFRoGgV-BCxVBTAcIihYDLcAc0TIghq7ALYAJUT-RJo6gJBNCS6YBGtbXmKRHiG3TzGxoVGGi1ibGfGlsH4J8bHVgTHA4IStwUjRbgQRVPL4BSvrm4UQJiyclQINCnQS9EhzuAhINmqDphAmslo1FsJjsI6gc-p4occ6Khjrs-glEQjMONhswwEj0NB+OgCAgCMIEFoaBpFGUflVupixujUKdJH8AB73KjIXgUJFKbrgOoASQAdgAHACuABcADoAZwAFgBLSoKsUcOVymUykUcEUAE3lACMlRr5XEAPYAWyNFrYHNwSE+Akw5k+9GGdQAglaxQAbJUAMyVcQ4UqVFpF9qk5jAkHoYAhcbOgpATSNTGjrGBsZ0xQEnrTRplYujefIIGI4DAdULAGElVGHRRxFTuHgkcykYWmuwOTXO2puFoTrRU01UIMDps1syROzwFg3cVhy6jvXJxyicMVzQl+B16mAPLSyWyuXBv1ShjuQbog4dYGNDk5WPyZDoYa8gU1kBHgCqAAqbD5skLi8EwphJEi5IgP4cBlL8aBsBa3DmEiBbGOIWDQGAeAdDg2D5AQvLYDStKBGwQA) \ No newline at end of file diff --git a/datasheets/MCP6001 but china.pdf b/datasheets/MCP6001 but china.pdf new file mode 100644 index 0000000..87ae037 Binary files /dev/null and b/datasheets/MCP6001 but china.pdf differ diff --git a/datasheets/MCP6001.pdf b/datasheets/MCP6001.pdf new file mode 100644 index 0000000..ce41f77 Binary files /dev/null and b/datasheets/MCP6001.pdf differ diff --git a/images/simulation.png b/images/simulation.png index 53b6063..c0c3ce3 100644 Binary files a/images/simulation.png and b/images/simulation.png differ