Multiple Analog outputs | Cypress Semiconductor
Multiple Analog outputs
I am looking at setting up a project that requires 4 x Analog outputs. The system receives digital data values from 0-1000 via a serial port. The values then need to be converted to 0-2.5 DC voltage and output to a pin.
The DAC appears to be 8-bit resolution and I have seen some apps for increasing resolution using 2 Dacs. However, would it be better to use 4 x PWM output and some op amps?
The internal opamps appear to provide rail to rail output. I was thinking of having PWM to Digital output pin and then a 2 pole Low pass filter connected back into PSOC to an opamp (to form a Sallen & Key filter to convert the PWM to DC voltage), finally a voltage follower and DC out a pin?
Or is there a more effcient way of doing this? I don't need much current, the 0-2,5V DC linear voltage is being used to control the setting of each of 4 x 4-20mA generation IC's
While I am on the topic of analog, Is there a component that can act as a shunt resistor to ground to convert 0-20mA signal input to 0-2V signal for measurement by ADC. Or would external resistor to ground be necessary?