An estimate of unit current element mismatch error in a digital to analog converter circuit is obtained through a correlation process. Unit current elements of the digital to analog converter circuit are actuated by bits of a thermometer coded signal generated in response to a quantization output signal. A correlation circuit generates the estimates of the unit current element mismatch error from a correlation of a first signal derived from the thermometer coded signal and a second signal derived from the quantization output signal.

An estimate of unit current element mismatch error in a digital to analog converter circuit is obtained through a correlation process. Unit current elements of the digital to analog converter circuit are actuated by bits of a thermometer coded signal generated in response to a quantization output signal. A correlation circuit generates the estimates of the unit current element mismatch error from a correlation of a first signal derived from the thermometer coded signal and a second signal derived from the quantization output signal.

Disclosed is an input impedance boosting apparatus. More particularly, an input impedance boosting apparatus including an analog-to-digital converter; an input capacitor connected to an input terminal of the analog-to-digital converter and a ground line and including a first shielding metal formed thereunder; a feedback capacitor connected onto a positive feedback loop of the analog-to-digital converter and including a second shielding metal formed thereunder; and an impedance booster connected to both ends of the feedback capacitor and configured to boost an input impedance based on a first parasitic component formed between the input capacitor and the first shielding metal and a second parasitic component formed between the feedback capacitor and the second shielding metal is provided.

A delay chain circuit with series coupled delay elements receives a reference clock signal and outputs phase-shifted clock signals. A multiplexer circuit receives the phase-shifted clock signals and selects among the phase-shifted clock signals for output as in response to a selection signal. The selection signal is generated by a control circuit from a periodic signal having a triangular wave profile. A sigma-delta modulator converts the periodic signal to a digital signal, and an integrator circuit integrates the digital signal to output the selection signal. The selected phase-shifted clock signal is applied as the reference signal to a phase locked loop which generates a spread spectrum clock signal.

An estimate of unit current element mismatch error in a digital to analog converter circuit is obtained through a correlation process. Unit current elements of the digital to analog converter circuit are actuated by bits of a thermometer coded signal generated in response to a quantization output signal. A correlation circuit generates the estimates of the unit current element mismatch error from a correlation of a first signal derived from the thermometer coded signal and a second signal derived from the quantization output signal.

A delay chain circuit with series coupled delay elements receives a reference clock signal and outputs phase-shifted clock signals. A multiplexer circuit receives the phase-shifted clock signals and selects among the phase-shifted clock signals for output as in response to a selection signal. The selection signal is generated by a control circuit from a periodic signal having a triangular wave profile. A sigma-delta modulator converts the periodic signal to a digital signal, and an integrator circuit integrates the digital signal to output the selection signal. The selected phase-shifted clock signal is applied as the reference signal to a phase locked loop which generates a spread spectrum clock signal.

An estimate of unit current element mismatch error in a digital to analog converter circuit is obtained through a correlation process. Unit current elements of the digital to analog converter circuit are actuated by bits of a thermometer coded signal generated in response to a quantization output signal. A correlation circuit generates the estimates of the unit current element mismatch error from a correlation of a first signal derived from the thermometer coded signal and a second signal derived from the quantization output signal.

A device (e.g., SAR ADC device) include a DAC circuit and generates a digital output based on logic circuitry that includes SAR logic. Additional logic circuitry includes delta modulation circuitry and dynamic element matching circuitry. The delta modulation circuitry provides several digital outputs of the SAR DAC, while the dynamic element matching circuitry selects a different set of capacitors from the DAC circuit. Each cycle is added together and averaged, and then added to the digital output from the SAR logic.

Disclosed is an input impedance boosting apparatus. More particularly, an input impedance boosting apparatus including an analog-to-digital converter; an input capacitor connected to an input terminal of the analog-to-digital converter and a ground line and including a first shielding metal formed thereunder; a feedback capacitor connected onto a positive feedback loop of the analog-to-digital converter and including a second shielding metal formed thereunder; and an impedance booster connected to both ends of the feedback capacitor and configured to boost an input impedance based on a first parasitic component formed between the input capacitor and the first shielding metal and a second parasitic component formed between the feedback capacitor and the second shielding metal is provided.

A device (e.g., SAR ADC device) include a DAC circuit and generates a digital output based on logic circuitry that includes SAR logic. Additional logic circuitry includes delta modulation circuitry and dynamic element matching circuitry. The delta modulation circuitry provides several digital outputs of the SAR DAC, while the dynamic element matching circuitry selects a different set of capacitors from the DAC circuit. Each cycle is added together and averaged, and then added to the digital output from the SAR logic.