Using the ADuC7060, can I measure a Grounded input signal?
If yes, are there any limitations?
The ADuC7060/61 contains 2 separate ADCs;
- ADC0 which has a PGA on its front end.
- ADC1 which has no PGA.
Both ADCs have an input buffer on their front end to allow measurement of high-impedance input signals.
These input buffers are not fully rail-to-rail - their input range is +100mV to Vdd-100mV.
When the input buffer is enabled, the common mode of the input signal must be greater than 100mV.
If a single-ended input measurement is selected, AIN5 input channel must be biased above 100mV
There is one condition that allows a grounded input signal - input signal < 100mV:
When ADC0 is set to a gain of 1 or 2, the negative input buffer is by-passed by default. Therefore only when the PGA is set to a gain of 1 or 2 is the input buffer bypassed by default.
Correction to my last post..
The input voltage range for ADC0 is 100mV to Vdd-0.7V
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