Data conversion circuitry for converting analog signals to digital signals and vice-versa and method therefor
AssigneeFreescale Semiconductor, Inc.
InventorsMichael T. Berens, James R. Feddeler
Life of this patent
Estimating the term…
Abstract
A data converter for converting analog signals to digital signals, or for converting digital signals to analog signals is provided. In one embodiment, a production self-test is provided. In one embodiment, a high-speed lower-resolution method or mode for a data converter is provided. In one embodiment, a differential data converter with a more stable comparator common mode voltage is provided. In one embodiment, the input range of a digitally calibrated data converter is provided and maintained so that there is no loss in input range due to the calibration. In one embodiment, digital post-processing of an uncalibrated result using a previously stored calibration value is provided.
Claims18
A method, comprising:
- providing one or more conductors for transferring control information, the control information selecting whether a data conversion in a data converter is to be a J-bit data conversion or an A-bit data conversion, wherein J and A are integers, and wherein the data converter has a charge redistribution array having a total capacitance C;
- when the J-bit data conversion is selected, performing the J-bit data conversion using the data converter;
- and
- when the A-bit data conversion is selected, performing the A-bit data conversion using the data converter,
- wherein the data converter is used to perform both the J-bit data conversion and the A-bit data conversion, and
- wherein the step of performing the A-bit data conversion using the data converter comprises:
- receiving an input voltage that is to be converted;
- using the input voltage to charge a first portion of the total capacitance C of the charge redistribution array, wherein the first portion of the total capacitance C of the charge redistribution array is less than all of the total capacitance C;
- performing a successive approximation on L most significant bits to produce an unscaled conversion result, wherein L is an integer less than J and greater than A;
- and
- shifting the unscaled conversion result to produce a scaled conversion result.
A data converter, comprising:
- storage circuitry for storing control information, the control information selecting whether a data conversion in the data converter is to be a J-bit data conversion or an A-bit data conversion, wherein J and A are integers;
- a charge redistribution array comprising a plurality of binary weighted elements;
- one or more input terminals for receiving an input to be converted;
- and
- control circuitry which receives the control information and in response determines which of the binary weighted elements to couple to the one or more input terminals,
- wherein when the data conversion in the data converter is the J-bit data conversion, the control circuitry couples all of the binary weighted elements to the one or more input terminals, and
- wherein when the data conversion in the data converter is the A-bit data conversion, the control circuitry couples only a portion of the binary weighted elements to the one or more input terminals, wherein the portion of the binary weighted elements is less than all of the binary weighted elements.
A method, comprising:
- providing mode select circuitry to select one of a plurality of conversion modes in a data converter;
- providing a first conversion mode of the plurality of conversion modes having a first resolution and having a first bandwidth;
- providing a second conversion mode of the plurality of conversion modes having a second resolution and having a second bandwidth,
- wherein the first resolution of the first conversion mode is higher than the second resolution of the second conversion mode, and
- wherein the first bandwidth of the first conversion mode is lower than the second bandwidth of the second conversion mode;
- wherein a sampling time of the second conversion mode is shorter than a sampling time of the first conversion mode;
- receiving an input voltage;
- converting a fraction of the input voltage to a digital value, wherein the fraction of the input voltage is less than one and greater than zero;
- and
- left shifting the digital value to produce a digital conversion result corresponding to the input voltage.
Dependencies are inferred from the claim text.