Reference voltage circuit
AssigneesKabushiki Kaisha Suwa Seikosha, Shinshu Seiki Kabushiki Kaisha
InventorsYoshikiyo Futagawa, Kanemitsu Kubota, Hiroshi Kamakura
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Abstract
An improved circuit for providing a fixed reference voltage with a minimum consumption of power is provided. The circuit includes a fixed voltage element adapted to be referenced to a fixed voltage. A charge storage element is coupled in series with a uni-directional current gating element, the series coupled charge storage element and uni-directional current gating element being coupled in parallel with the fixed voltage element. A voltage supply intermittently applies a referencing voltage across the fixed voltage element to thereby intermittently charge the charge storage element to a fixed reference voltage for at least a predetermined period of time.
Claims21
A circuit for producing a reference voltage, comprising in combination, a fixed voltage means adapted to be referenced to a fixed voltage in response to a referencing voltage being applied thereto, a charge storage means adapted to be charged to a reference voltage, a current gating means coupled in series with said charge storage means, said series coupled current gating means and said charge storage means being coupled in parallel with said fixed voltage means, and supply means for supplying a referencing voltage, a first switching means disposed intermediate said supply means and said fixed voltage means for intermittently applying said referencing voltage to said charge storage means and said fixed voltage means to thereby intermittently charge said charge storage means to a fixed reference voltage for at least a predetermined period of time.
In an analog-to-digital converter circuit including reference voltage circuit means for producing a fixed reference voltage, integrator circuit means for integrating said fixed reference voltage, comparator means for comparing the voltage level of said integrated fixed reference voltage with a further voltage level, and control means coupled to the comparator means for producing a digital count representative of the magnitude of said further voltage level, the improvement comprising said fixed reference voltage circuit including a fixed voltage means adapted to be referenced to a fixed voltage in response to a referencing voltage being applied thereto, charge storage means coupled to said integrator circuit means and adapted to be charged to a reference voltage, a current gating means coupled in series with said charge storage means, said series-coupled current gating means and said charge storage means being coupled in parallel with said fixed voltage means, and supply means coupled to said control means for supplying a referencing voltage, a first transistor switching means disposed intermediate said supply means and said fixed voltage means for intermittently applying said referencing voltage to said charge storage means and said fixed voltage means for a sufficient interval of time to charge said storage means to a reference voltage when said fixed reference voltage is to be integrated by said integrator means.
Dependencies are inferred from the claim text.