Hi,
I am designing a power supply which requires a very low voltage ripple at the output. I worked out that to achieve the level of ripple required the ADC must have at least 16 bits. I am using the F2837xD Microprocessor which can work in either 12-bit "single-ended" mode or 16-bit differential mode. I have seen multiple sources online say that it is possible to use differential mode inputs even for ground referenced signals by connecting the negative differential input to the analogue ground. When looking through the data sheet, TMS320F2837xD Dual-Core Delfino Microcontrollers Technical Reference Manual (Rev. I) (ti.com) Page 1560, it shows the configuration of the differential inputs of the ADC.
My question is, if I was to ground the negative input of the ADC in differential mode, would this be acceptable, or would it cause issues? My concern is obviously that grounding the negative terminal will short out the lower capacitor. See image below:
I am planning on using oversampling and interleaving of the ADC's but it is still not enough when using the single-ended ADC mode with only 12-bits of resolution.
Any comments welcomed.
SIC
I am designing a power supply which requires a very low voltage ripple at the output. I worked out that to achieve the level of ripple required the ADC must have at least 16 bits. I am using the F2837xD Microprocessor which can work in either 12-bit "single-ended" mode or 16-bit differential mode. I have seen multiple sources online say that it is possible to use differential mode inputs even for ground referenced signals by connecting the negative differential input to the analogue ground. When looking through the data sheet, TMS320F2837xD Dual-Core Delfino Microcontrollers Technical Reference Manual (Rev. I) (ti.com) Page 1560, it shows the configuration of the differential inputs of the ADC.
My question is, if I was to ground the negative input of the ADC in differential mode, would this be acceptable, or would it cause issues? My concern is obviously that grounding the negative terminal will short out the lower capacitor. See image below:
I am planning on using oversampling and interleaving of the ADC's but it is still not enough when using the single-ended ADC mode with only 12-bits of resolution.
Any comments welcomed.
SIC