Analog-to-digital converter with dynamic range enhancer

A circuit, comprising:

• a programmable gain amplifier (PGA) having a PGA output;
• an analog-to-digital converter (ADC) having an input coupled to the PGA output, the ADC having an ADC output;
• a digital signal chain coupled to the ADC output;
• and
• a dynamic range enhancer (DRE) circuit configured to:
• monitor a signal level of, or derived from, the ADC output;
• and
• responsive to the signal level being less than a DRE threshold, program the PGA for a gain level greater than unity gain and cause the digital signal chain to implement an attenuation of a same magnitude as the gain level to be programmed into the PGA.

A circuit, comprising:

• a programmable gain amplifier (PGA) having a PGA output;
• a delta-sigma modulator having an input coupled to the PGA output, the delta-sigma modulator having a delta-sigma modulator output;
• a digital filter coupled to the delta-sigma modulator output;
• and
• a dynamic range enhancer (DRE) circuit coupled to the delta-sigma modulator output and to the PGA, the DRE circuit is configured to:
• monitor a signal level of the delta-sigma modulator output;
• and
• responsive to the signal level being less than a DRE threshold, program the PGA for a gain level greater than unity gain and cause the digital filter to implement an attenuation of a same magnitude as the gain level to be programmed into the PGA, wherein the DRE circuit is configured to program the gain level for the PGA based on a comparison of an output signal derived from the delta-sigma modulator output and a threshold.