Texas Instruments Corporation

Binling Zhou

Binan Wang

James Lee Todsen

Brian David Johnson

A cascaded delta-sigma modulator includes a first stage delta-sigma modulator (A) having first adder () followed by first () and second () integrators, a second adder (), and a quantizer () the output of which is fed back to the first adder by an A/D (). A gain circuit () is also connected between the first integrator and the second adder. The quantizer output is coupled by interstage circuitry to a second stage converter (B) having a transfer function represented by the expression OUT(z)=zIN(z)+G(z)E2(z). An error cancellation circuit () includes inputs coupled to the output of the quantizer and an output of the second stage converter so as to provide a flat transfer function of the cascaded first stage delta-sigma modulator and second stage converter and the error cancellation circuit, despite non-flatness in a transfer function of the first stage delta-sigma modulator.

Feed-forward circuitry and corresponding error cancellation circuit for cascaded delta-sigma modulator

A bottom die and a top die stacked on the bottom die are configured to provide a daisy chain function. Both die include an input/output function control bonding pad (G), a first bonding pad (C) controllable to function as either an input or an output, and a second bonding pad (E) controllable to function as either an output or an electrically floating pad in response to a corresponding input/output function control signal. The top die () is stacked on the bottom die () and the first bonding pad (C) of the bottom die () is wire bonded to the first bonding pad (C) of the top die (). A first reference voltage (VDD) on the function control bonding pad of the bottom die configures its first bonding pad as an output and its second bonding pad as electrically floating, and a second reference voltage (VSS) on the function control bonding pad of the top die configures its first bonding pad as an input and its second bonding pad as an output, to thereby provide the daisy chain function.

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Tucson, AZ, United States of America

Binling Zhou