Oversampled digital-to-analog converter based on nonlinear separation and linear recombination

A digital-to-analog converter system, receiving a multi-bit digital input signal and providing an analog output signal comprising:

• a digital subtractor, receiving said multi-bit digital input signal and a main digital signal, and providing a first digital signal;
• a first loop filter receiving a part of said first digital signal and providing a second digital signal;
• a controller providing said main digital signal;
• said controller assuring that said second digital signal remains bounded;
• said main digital signal being a function of at least one signal other than said second digital signal;
• a main digital-to-analog converter, receiving said main digital signal, and providing a main analog signal;
• a filtering digital-to-analog converter, receiving a part of said second digital signal and providing an analog compensation signal;
• said filtering digital-to-analog converter having a frequency-dependent gain;
• an analog adder, receiving said main analog signal and said analog compensation signal, and providing the analog output signal;
• whereby the digital-to-analog converter system provides a digital-to-analog conversion.

A digital-to-analog converter system receiving a multi-bit digital input signal and providing an analog output signal comprising:

• a separator separating said multi-bit digital input signal into a main digital signal and at least two digital compensation signals;
• a main digital-to-analog converter receiving said main digital signal and providing a main analog signal;
• an array of digital-to-analog converters, receiving parts of said two digital compensation signals and providing two temporary analog signals;
• an array of analog filters receiving said two temporary analog signals and providing two analog compensation signals;
• an analog adder summing said main analog signal and at least said two analog compensation signals;
• whereby the digital-to-analog converter provides a digital-to-analog conversion.

A method for converting a multi-bit digital input signal to an analog output signal comprising the following steps:

• separating said multi-bit digital input signal into a main digital signal and at least one digital compensation signal,
• converting said main digital signal into a main analog signal,
• converting said digital compensation signal into an analog compensation signal using a mismatch-shaping digital-to-analog converter, said mismatch-shaping digital-to-analog converter including a digital state machine that is updated as a function of said digital compensation signal,
• adding said main analog signal and said analog compensation signal to generate the analog output signal.