Integrated analog-to-digital converter
AssigneeMicrochip Technology Incorporated
InventorsDavid Rich, Peter Staley
Life of this patent
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Abstract
A feedback coder, which employs simple CMOS push/pull amplifiers as gain elements, along with a bistable circuit, in its preferred embodiment takes the form of a second-order delta-sigma modulator. The output of the modulator is converted into pulse code modulated words by a finite impulse response filter which incorporates a partial coefficient generator utilizing simplified logic. The generator output is provided to an accumulator in which the stages operate at reduced speed. A simple multiplexer generates a serial output. The entire converter can be integrated on a semiconductor chip of relatively small area.
Claims33
A feedback coder comprising summation means having first and second inputs and an output, said first input of said summation means receiving an analog signal to be coded, first filter means having an input operably connected to said output of said summation means, analog-to-digital conversion means having an input operably connected to said first filter means and an output, second filter means operably connected between said output of said analog-to-digital conversion means and said second input of said summation means, digital-to-analog conversion means operably connected between said output of said analog-to-digital conversion means and said second filter means, the output of said analog-to-digital conversion means forming the coder output, each of said filter means comprising CMOS push/pull amplification means.
A feedback coder comprising first and second summation means, each having first and second inputs and an output, said first input of said first summation means receiving an analog signal to be coded, first filter means operably connected between said output of said first summation means and said first input of said second summation means, second filter means, analog-to-digital conversion means, and digital-to-analog conversion means, said second filter means being operably connected between said output of said second summation means and said analog-to-digital conversion means, said analog-to-digital conversion means being operably connected between said second filter means and the input of said digital-to-analog conversion means, the output of said digital-to-analog conversion means being connected to said second input of each of said first and second summation means, the output of said analog-to-digital conversion means forming the coder output, each of said first and second filter means comprising CMOS push/pull amplification means.
A feedback coder comprising first and second summation means, each having first and second inputs and an output, first and second filter means, and bistable means, said first input of said first summation means being operably connected to receive the analog input to be coded, the input of said first filter means being operably connected to the output of said first summation means, said first input of said second summation means being operably connected to the output of said first filter means, the input of said second filter means being operably connected to the output of said second summation means, the input of said bistable means being operably connected to the output of said second filter means, said output of said bistable means being operably connected to said second input of said second summation means, said second input of said first summation means and the coder output, each of said filter means comprising CMOS push/pull amplification means.
Dependencies are inferred from the claim text.