There are two places in the Delta Sigma ADC where a user can add a gain to an input signal.
- Gain in the Input Buffer: The ADC has a differential input buffer stage which can have gain settings of 1, 2, 4, 8. The gain can be set in the ADC component properties in the PSoC Creator. In order to use the gain in the buffer the user has to have the buffer enabled in the design.
- Gain in the Delta Sigma modulator: The user can also add a gain in the modulator stage of the ADC itself. The gain on the modulator stage converts as a range change for the
ADC. At a gain of one the ADC works on a range of +/-Vref. At a gain of two the range would be +/- Vref/2. The ADC can give a gain of 1x, 2x or 4x. The gain in the delta sigma modulator can be set using the range selection in the ADC component in PSoC Creator.
Taking into consideration the 8x gain in buffer and a 4x gain in modulator the ADC can have a maximum of a 32x gain internal to the block.