I've got a hypothetical question for you all.. IF I were to go with an MCU that did not have an ADC on it and you wanted to included an external ADC connected via SPI or I2C (for example), what would you look for spec-wise on such a part -- specifically sample times, # of channels, resolution,etc..
Most of the ADCs I see in μC's are either 10 or 12 bits of resolution and have pretty fast sample times (~1Msps for example on some PICs).. One other parameter on this would be part cost -- I'm not interested in the $10/ea in small qty parts... I could however go with say 4 single channel ADC's since I don't think it would be an issue design wise -- if that route would be cheaper than a single 4-channel ADC for example.. Is there anything else I need to look for? Obviously single-ended inputs to allow reading from thermistors and whatnot..
Thx!
Most of the ADCs I see in μC's are either 10 or 12 bits of resolution and have pretty fast sample times (~1Msps for example on some PICs).. One other parameter on this would be part cost -- I'm not interested in the $10/ea in small qty parts... I could however go with say 4 single channel ADC's since I don't think it would be an issue design wise -- if that route would be cheaper than a single 4-channel ADC for example.. Is there anything else I need to look for? Obviously single-ended inputs to allow reading from thermistors and whatnot..
Thx!