Device for generating a DC reference voltage

Claim 1

A device for generating a DC reference voltage approximately equal to half a DC supply voltage provided to said device, said device including: an input stage, forming a first potentiometric divider comprising a first branch connected to the power supply voltage and a second branch connected to the reference potential, the first and second branches having an asymmetric behaviour in response to variations in the room and/or operating temperature, the variations in operating temperature being linked to the quality of the manufacturing process of the device, said input stage supplying a first DC voltage (NBGP) with a static component and a dynamic component; an intermediate stage, forming a resistive and capacitive filter, which receives the first DC input voltage (NGBP), eliminates its dynamic component, and supplies a second DC output voltage (NARF); and an output stage, forming a second potentiometric divider comprising a first branch connected to said power supply voltage and a second branch connected to said reference potential, the first and second branches of said second potentiometric divider having an asymmetric behaviour similar to the behaviour of the first and second branches of said first potentiometric divider, the relative voltage variations of said second divider as a function of the room and/or operating temperature being however smaller than the relative voltage variations of said first divider, the variations in operating temperature being linked to the quality of the manufacturing process, said output stage comprising in addition a logic inverter function, said output stage supplying a third DC voltage (NREF), the variations of which as a function of the room and/or operating temperature, said variations in operating temperature being linked to the quality of the manufacturing process, are the inverse of those of the said second DC voltage (NARF), said variations in the second DC voltage (NARF) being thus compensated.

Claim 2

A device for generating a DC reference voltage approximately equal to half a DC supply voltage provided to said device, said device including: an input stage, forming a first potentiometric divider comprising a first branch connected to the power supply voltage and a second branch connected to the reference potential, the first and second branches having an asymmetric behaviour in response to variations in the room and/or operating temperature, the variations in operating temperature being linked to the quality of the manufacturing process of the device, said input stage supplying a first DC voltage (NBGP) with a static component and a dynamic component; an intermediate stage, forming a resistive and capacitive filter, which receives the first DC input voltage (NGBP), eliminates its dynamic component, and supplies a second DC output voltage (NARF); and an output stage, forming a second potentiometric divider comprising a first branch connected to said power supply voltage and a second branch connected to said reference potential, the first and second branches of said second potentiometric divider having an asymmetric behaviour similar to the behaviour of the first and second branches of said first potentiometric divider, the relative voltage variations of said second divider as a function of the room and/or operating temperature being however smaller than the relative voltage variations of said first divider, the variations in operating temperature being linked to the quality of the manufacturing process, said output stage comprising in addition a logic inverter function, said output stage supplying a third DC voltage (NREF), the variations of which as a function of the room and/or operating temperature, said variations in operating temperature being linked to the quality of the manufacturing process, are the inverse of those of the said second DC voltage (NARF), said variations in the second DC voltage (NARF) being thus compensated.