Circuit with a digital to analog converter

摘要

A first and second signal source are coupled to an analog output in a digital input signal dependent configuration. The signal sources so that a contribution of their source signals adds up in a first or a second direction when the digital input assumes a first or a second value respectively. The source signals counteract each other when the digital input signal assumes a third value. The signs with which the source signals contribute to the analog signal level for the third value are alternated, so that both signs occur substantially equally frequently for each of the signal sources. The spectral density of a deviation signal due to said alternating is concentrated at high frequencies. In an embodiment the spectral density is moved to high frequency by modulating the alternation onto a high frequency alternation that is used to generate return to zero levels between digital input signal dependent levels.