Making precision flexiforce circuit - Negative Reference
groggory
Posts: 205
I'm making my 3rd iteration of a precision flexiforce circuit going into a 12bit DAC.
I still have some background noise coming in that I want to get rid of and I think my negative voltage reference may be partially to blame.
I'm using a MAX764 with the feedback circuit to give me 3.3V. But when I throw it on the o-scope it is coming out a little noisy (50mV noise). I have plenty of filter capacitors on it but it doesn't seem to help.
I'm thinking about adding a National LT1964 negative voltage reference behind this voltage inverter circuit.
Note: Vin is 6V coming off alkalines. I have my schematic listed as MAX764-766, but I'm using 764. All work is done on a 2 layer PCB
What do you think? Here's my current circuit:
I still have some background noise coming in that I want to get rid of and I think my negative voltage reference may be partially to blame.
I'm using a MAX764 with the feedback circuit to give me 3.3V. But when I throw it on the o-scope it is coming out a little noisy (50mV noise). I have plenty of filter capacitors on it but it doesn't seem to help.
I'm thinking about adding a National LT1964 negative voltage reference behind this voltage inverter circuit.
Note: Vin is 6V coming off alkalines. I have my schematic listed as MAX764-766, but I'm using 764. All work is done on a 2 layer PCB
What do you think? Here's my current circuit: