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US 9,069,995 B1Granted
Multiply accumulate operations in the analog domain
AssigneeKandou Labs, S.A.
InventorHarm Cronie
Life of this patent
Estimating the term…
Abstract
Fixed capacitive circuits are described which perform arithmetical summation operations over sets of scaled analog values, where the constant parameters of the summations and scaling multiplications are formed as ratios of circuit element values. The passive nature of the design can enable efficient integrated circuit implementation.
Claims20
An apparatus for performing a multiply accumulate operation, the apparatus comprising:
- multiple inputs configured to receive multiple voltages, each voltage representing one input value to the multiply accumulate function,
- a fixed capacitor network, comprising two or more first input capacitors, one or more second series capacitors, and one or more result nodes comprising a result node capacitor, wherein the first input capacitors connect each input to one of at least one summation nodes, and the second series input capacitors connecting one or more summation nodes to one of at least one result node,
- wherein the voltage present on a result node represents a weighted sum of values represented at each connected summation node, the voltage present on each summation node represents a weighted sum of values at each connected input, and the weighted sums represent multiplication of a value by a constant determined by capacitive values in the fixed capacitor network.
An apparatus for multiply accumulate operations, the apparatus comprising:
- a plurality of circuit inputs configured at least to receive a plurality of input voltages, the plurality of input voltages corresponding to input values of a multiply accumulate operation;
- at least one circuit output configured at least to provide at least one output voltage, the at least one output voltage corresponding to at least one result of the multiply accumulate operation;
- and
- a capacitor network communicatively coupled with the plurality of circuit inputs and the at least one circuit output, the capacitor network including:
- a first set of fixed capacitors each configured at least to receive, at an input terminal, a voltage corresponding to one of the input values of the multiply accumulate operation;
- and
- a second set of fixed capacitors each having an input terminal communicatively coupled with output terminals of a plurality of the first set of fixed capacitors, the second set of fixed capacitors having a plurality of output terminals communicatively coupled with the at least one circuit output such that the at least one output voltage at the at least one circuit output corresponds to the at least one result of the multiply accumulate operation.
4 more elements
A method for multiply accumulate operations, the method comprising:
- receiving, at a plurality of circuit inputs, a plurality of input voltage signals corresponding to input values of a multiply accumulate operation;
- propagating each the plurality of input voltage signals to one a plurality of input terminals of a first set of fixed capacitors thereby creating corresponding capacitor network voltage signals at corresponding output terminals of the first set of fixed capacitors;
- and
- propagating the capacitor network voltage signals to a plurality of input terminals of a second set of fixed capacitors thereby creating at least one corresponding output voltage signal, the second set of fixed capacitors being communicatively coupled with the first set of fixed capacitors such that the at least one output voltage signal corresponds to at least one result of the multiply accumulate operation.
1 more element
Dependencies are inferred from the claim text.