Abstract: A device implemented in a N-bit digital-to-analog converter (DAC) to extend its resolution to N+P bits. The N-bit DAC comprises a resistive string 2 made of 2.sup.N resistive elements R1 to R16. MSB switches in block 10 and LSB switches in block 12, when closed in response to combinations of the N-bits provide the voltage at one of taps N1 to N16 to node M1. The device comprises a string 18 made of 2.sup.P-2 elements connected between nodes M1 and M7, additional LSB switch block 14 and additional MSB switches SW4-2, SW8-2, SW12-2 and SW16-2 which are closed in response to combinations of the N-bits to connect the string 18 across the taps of a selected resistor R1 to R16. The voltage generated at one of the taps M1 to M7 of string 18 is provided to the (N+P)-bit DAC output 20 by means of one of the switches in block 16. The main advantages of this device are that the monotonicity of the conversion is not impaired by the extension to (N+P) bits, and that it is not space consuming when integrated in a chip.