Methods and systems for analog-to-digital conversion (ADC) using an ultra small capacitor array with full range and sub-range modes
First Claim
1. An apparatus comprising:
- a comparator, the comparator is configured with a first high input, a first low input, and is configure to receive a clock signal;
a logic/latch block, the logic/latch block is configured to receive the clock signal and an output from the comparator, the logic/latch block is configured to output a control signal and a digital N-bit output signal; and
a first local charge-averaging capacitor array (LCACA), the first LCACA is configured to receive the control signal and a reference voltage, an output of the first LCACA is coupled to the first low input, the first LCACA is divided into a high sub-array and a low sub-array, the high sub-array to be pre-charged to a high reference voltage and the low sub-array to be pre-charged to a low reference voltage, the high reference voltage is greater than the low reference voltage, wherein in operation an analog signal is input to the first high input and the digital N-bit output signal is the digital conversion of the analog signal.
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Accused Products
Abstract
Methods and apparatuses are described to convert analog signals to digital signals using a local charge averaging capacitor array (LCACA) in an analog-to-digital converter (ADC.) An apparatus includes a comparator. The comparator is configured with a first high input, a first low input, and is configure to receive a clock signal. A logic/latch block is configured to receive the clock signal and an output from the comparator. The logic/latch block is configured to output a control signal and a digital N-bit output signal. A local charge-averaging capacitor array (LCACA) is configured to receive the control signal and a reference voltage. An output of the LCACA is coupled to the first low input. The first LCACA is divided into a high sub-array and a low sub-array. The high sub-array is pre-charged to a high reference voltage and the low sub-array is pre-charged to a low reference voltage. The high reference voltage is greater than the low reference voltage. In operation, an analog signal is input to the first high input and the digital N-bit output signal is the digital conversion of the analog signal.
48 Citations
20 Claims
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1. An apparatus comprising:
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a comparator, the comparator is configured with a first high input, a first low input, and is configure to receive a clock signal; a logic/latch block, the logic/latch block is configured to receive the clock signal and an output from the comparator, the logic/latch block is configured to output a control signal and a digital N-bit output signal; and a first local charge-averaging capacitor array (LCACA), the first LCACA is configured to receive the control signal and a reference voltage, an output of the first LCACA is coupled to the first low input, the first LCACA is divided into a high sub-array and a low sub-array, the high sub-array to be pre-charged to a high reference voltage and the low sub-array to be pre-charged to a low reference voltage, the high reference voltage is greater than the low reference voltage, wherein in operation an analog signal is input to the first high input and the digital N-bit output signal is the digital conversion of the analog signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus comprising:
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an M-bit analog-to-digital converter (ADC), the M-Bit ADC is configured to receive an input analog signal and to assign the input analog signal to a first section of an M-bit digital output signal having 2M sections, a residue voltage and at least one reference voltage; an N-bit analog-to-digital converter (ADC), the N-bit ADC is configured to receive as an input the residue voltage and the at least one reference voltage, the N-bit ADC converter further comprising; a comparator, the comparator is configured to receive the output signal on a first high input, the comparator has a first low input, and the comparator is configure to receive a clock signal; a logic/latch block, the logic/latch block is configured to receive the clock signal and an output signal from the comparator, the logic/latch block is configured to output a control signal and a digital N-bit output signal; and a local charge-averaging capacitor array (LCACA), the LCACA is configured to receive the residue voltage and the at least one reference voltage, an output signal of the LCACA is coupled to the first low input, the LCACA is divided into a left sub-array and a right sub-array, the left sub-array and the right sub-array are pre-charged to different voltages in a predefined order according to section number, wherein in operation the output signal of the LCACA is input on the first high input and the digital conversion of the analog signal contains M+N bits. - View Dependent Claims (10, 11, 12)
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13. A method for converting an input analog signal to digital comprising:
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pre-charging a least significant bit (LSB) sub-array of a local charge-averaging capacitor array (LCACA) to a first voltage; pre-charging a most significant bit (MSB) sub-array of the local charge-averaging capacitor array (LCACA) to a second voltage, wherein the second voltage is greater than the first voltage; selecting a first number of capacitors from the LCACA to produce an average voltage; analyzing an output of a comparator in response to the average voltage; and repeating the steps of selecting a number of capacitors from the LCACA and analyzing an output of a comparator to identify a digital output representative of a voltage of the input analog signal. - View Dependent Claims (14, 15, 16)
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17. A logic implemented in an integrated circuit, the logic to convert an input analog signal to digital, the logic comprising:
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pre-charging means for pre-charging a least significant bit (LSB) sub-array of a local charge-averaging capacitor array (LCACA) to a first voltage and for pre-charging a most significant bit (MSB) sub-array of the local charge-averaging capacitor array (LCACA) to a second voltage, wherein the second voltage is greater than the first voltage; means for selecting a first number of capacitors from the LCACA to produce an average voltage; means for analyzing an output of a comparator in response to the average voltage; and means for determining whether to repeat the selecting with a second number of capacitors and the analyzing an output of the comparator. - View Dependent Claims (18, 19, 20)
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Specification