Current mode analog-to-digital converter
AssigneeSiflare, Inc.
InventorsRex K. Hales, Marcellus C. Harper, Tracy Johancsik, Yusuf Haque
Life of this patent
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Abstract
A current-mode analog-to-digital converter includes: a current input node; a current-mode sample and hold circuit configured to output a steady source of electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node; and at least one current comparator that compares the electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node.
Claims35
A pipelined current-mode analog to digital converter comprising a number of stages, a first stage of said current-mode analog to digital converter comprising:
- a current input node;
- a current-mode sample and hold circuit configured to output an electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node wherein the current-mode sample and hold circuit comprises a plurality of output nodes, each of said output nodes outputting a separate electrical current having an analog value proportional to the sampled analog value of the electrical current at the current input node;
- and
- at least one current comparator configured to compare the electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node.
An analog-to-digital converter, comprising:
- a voltage-mode stage comprising circuitry that receives an input signal at a voltage input node, produces a digital representation of a sampled voltage of the input signal, produces a reconstruction voltage based on the digital construction of the sampled voltage, and outputs a first current representative of a difference between the reconstruction voltage and the sampled voltage of the input signal;
- and
- a current-mode stage comprising a current input node that receives the first electrical current output from the voltage-mode stage, a current-mode sample and hold circuit that outputs a second electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node, and at least one current comparator that compares the second electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node wherein the current-mode sample and hold circuit comprises a plurality of output nodes, each of said output nodes outputting a separate electrical current having an analog value proportional to the sampled analog value of the electrical current at the current input node.
A system of measuring current, comprising:
- an analog to digital converter, said analog to digital converter comprising:
- a current input node;
- a current-mode sample and hold circuit configured to output a steady source of electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node;
- and
- at least one current comparator configured to compare the electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node on at least one digital output node;
- and
- an electrical switch in electrical communication with said current input node, wherein said switch is configured to selectively couple one of a plurality of current sources to said current input node;
- and
- an electrical switch in electrical communication with said current output node, wherein said switch is configured to selectively couple said current output node to one of a plurality of current drains.
A method of obtaining a digital representation of an analog current signal with a first stage of a pipelined current mode analog to digital converter, said method comprising:
- receiving with said first stage, an ion electrical current;
- outputting from a current-mode sample and hold circuit an electrical current having an analog value proportional to a sampled analog value of the input electrical current wherein the current-mode sample and hold circuit comprises a plurality of output nodes, each of said output nodes outputting a separate electrical current having an analog value proportional to the sampled analog value of the electrical current at the current input node;
- comparing the analog value of the electrical current output from the current-mode sample and hold circuit to at least one reference current using a current comparator;
- and
- outputting to a digital output node a digital result of the comparison of the analog value of the electrical current output from the audit-mode sample and hold circuit to the at least one reference current.
Dependencies are inferred from the claim text.