Hello,
I am looking for some advice regarding a project: I need to design a voltage controlled current source. The voltage is supplied by an 8-bit DAC from a PIC μC (then low pass filtered) and the output of the VCCS drives the primary of an LVDT sensor. The voltage and corresponding current waveform should be triangular with amplitude of 0-15mA peak to peak with a frequency of 10kHz. The power supply is 5V and it should be able to function at high temperatures (125°C). I would like to design it with as few components (cheap) as possible.
I simulated the OP configuration in the attached image (R=330Ω). I am seeing a lot of ringing on the rising and falling slopes and the voltage slopes off at the peaks (it is no longer linear after 70% of the rise/fall) which is not desired for my application. I don't know if this is a result of the compliance voltage or if the bandwidth of the OP (I was using one with 2MHz in the simulation).
I would appreciate it if anyone could give me any advice with regard to implementing this correctly, advice in picking picking an appropriate OP or a suggestion for a better OP configuration/implementation. All help is greatly appreciated!
I am looking for some advice regarding a project: I need to design a voltage controlled current source. The voltage is supplied by an 8-bit DAC from a PIC μC (then low pass filtered) and the output of the VCCS drives the primary of an LVDT sensor. The voltage and corresponding current waveform should be triangular with amplitude of 0-15mA peak to peak with a frequency of 10kHz. The power supply is 5V and it should be able to function at high temperatures (125°C). I would like to design it with as few components (cheap) as possible.
I simulated the OP configuration in the attached image (R=330Ω). I am seeing a lot of ringing on the rising and falling slopes and the voltage slopes off at the peaks (it is no longer linear after 70% of the rise/fall) which is not desired for my application. I don't know if this is a result of the compliance voltage or if the bandwidth of the OP (I was using one with 2MHz in the simulation).
I would appreciate it if anyone could give me any advice with regard to implementing this correctly, advice in picking picking an appropriate OP or a suggestion for a better OP configuration/implementation. All help is greatly appreciated!
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