1. Digital to analog conversion circuit able to transform a digital input signal having n bit in an output analog signal comprising: a thermometric decoder having said digital input signal in input and able to produce said signal having a thermometric code with 2 n −1 bit in output; a digital to analog converter with modular elements including 2 n −1 controlled switches; a shift register able to receive said digital signal having 2 n −1 bit in a data input and able to produce 2 n −1 control signals of said controlled switches in output; a delay circuit of said of digital input signal having the output connected to a shift input of said shift register and able to produce a delayed digital signal in output as to make said digital signal having 2 n −1 bit shift by a number of bit equal to the value of said delayed digital signal; characterised by further comprising a generator of a digital random number selected in a range of prefixed values and having a prefixed probability of occurrence; an adder node able to receive said random digital number and said delayed digital signal in input whose output is connected to said shift input of said shift register.