Analog to digital converter with inverter based amplifier
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorMartin Kinyua
Life of this patent
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Abstract
An analog-to-digital converter (“ADC”) includes an input terminal configured to receive an analog input voltage signal. A first ADC stage is coupled to the input terminal and is configured to output a first digital value corresponding to the analog input voltage signal and a first analog residue signal corresponding to a difference between the first digital value and the analog input signal. An inverter based residue amplifier is configured to receive the first analog residue signal, amplify the first analog residue signal, and output an amplified residue signal. The amplified residue signal is converted to a second digital value, and the first and second digital values are combined to create a digital output signal corresponding to the analog input voltage signal.
Claims20
An analog-to-digital converter (“ADC”), comprising:
- an input terminal configured to receive an analog input voltage signal;
- a first ADC stage coupled to the input terminal and configured to sample the analog input voltage signal during a first operation phase, the first ADC stage configured to convert the sampled analog input voltage signal to a first digital value during a second operation phase, and determine a first analog residue signal corresponding to a difference between the first digital value and the analog input voltage signal during the second operation phase;
- a first inverter based residue amplifier configured to amplify the first analog residue signal during a third operation phase, wherein the first inverter based residue amplifier is disabled during the first operation phase;
- and
- a second ADC stage configured to convert the amplified first analog residue signal to a second digital value corresponding to the amplified first analog residue signal during the first operation phase;
- and
- a controller coupled to the first and second ADC stages configured to combine the first and second digital values to a digital output signal representing the analog input voltage signal.
An amplifier, comprising:
- a first amplifier stage having an input inverter coupled between first and second voltage terminals, the first amplifier stage configured to receive a first analog signal;
- a second amplifier stage having first and second inverters coupled between the first and second voltage terminals and configured to receive an output of the first amplifier stage, and corresponding first and second control devices configured to control current flow through the first and second inverters in response to a control signal;
- a third amplifier stage including an output inverter coupled between the first and second voltage terminals and configured to receive an output of the second amplifier stage;
- and
- a control circuit coupled to the first and second control devices and configured to generate the control signal.
A method, comprising:
- sampling an analog input voltage signal;
- determining a first digital value corresponding to the analog input voltage signal by a first ADC stage;
- determining a first analog residue signal corresponding to a difference between the first digital value and the analog input voltage signal by the first ADC stage;
- amplifying the first analog residue signal by a first inverter based residue amplifier;
- determining a second digital value corresponding to the amplified first analog residue signal by a second ADC stage;
- determining a second analog residue signal corresponding to a difference between the second digital value and the amplified first analog residue signal by the second ADC stage;
- amplifying the second analog residue signal by a second inverter based residue amplifier;
- determining a third digital value corresponding to the second amplified analog residue signal by a third ADC stage;
- and
- combining the first, second and third digital values into a digital output signal representing the analog input voltage signal.
Dependencies are inferred from the claim text.