The invention discloses an ultrahigh-precision low-
noise band-gap
reference circuit, and relates to the technical field of
integrated circuit design, the ultrahigh-precision low-
noise band-gap
reference circuit comprises a starting turn-off circuit, a reference core circuit, a high-order temperature compensation circuit and a digital trimming circuit, the starting turn-off circuit is connected with the reference core circuit, and the high-order temperature compensation circuit is connected with the digital trimming circuit through a Brokaw type band-gap reference topological structure. Accurate compensation of the
voltage is achieved through deep
negative feedback of the
operational amplifier and a high-order temperature compensation circuit, and the temperature drift of the reference
voltage is as low as 0.5-2 ppm / DEG C (-40 DEG C to 130 DEG C) and is increased by 5-10 times compared with a traditional band-gap reference (5-10 ppm / DEG C). The
power consumption of the
system can be saved by turning off the circuit when the circuit is not used, meanwhile, the digital trimming module is added to replace
laser trimming in traditional
engineering, the upper limit of the trimming range is improved, high-order temperature compensation and the digital trimming circuit are introduced, the precision of output
voltage is improved, different devices are replaced, and the
noise of the circuit is reduced. The problems that a traditional high-voltage band-gap reference
temperature coefficient is high and noise is large are solved.