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:
- first and second input terminals configured to receive an analog input voltage signal;
- a first ADC stage coupled to the input terminal and 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;
- a first amplifier stage including a first inverter having a residue input terminal configured to receive the first analog residue signal;
- a second amplifier stage having first and second inverters 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 configured to receive an output of the second amplifier stage and output a first amplified residue signal;
- a second ADC stage configured to receive the first amplified residue signal and output a second digital value corresponding to the first amplified analog residue signal;
- a controller configured to combine the first and second digital values into a digital output signal representing the analog input voltage signal.
A method, comprising:
- receiving an analog input signal;
- receiving the analog input signal by a first amplifier stage having an input inverter coupled between first and second voltage terminals;
- providing an output of the first amplifier stage to a second amplifier stage having first and second inverters coupled between the first and second voltage terminals;
- controlling current flow through the first and second inverters of the second amplifier stage by inputting first and second control signals to corresponding first and second control devices;
- providing an output of the second amplifier stage to a third amplifier stage including an output inverter coupled between the first and second voltage terminals;
- and
- outputting an amplified output signal corresponding to the analog input signal by the third amplifier stage.
An analog-to-digital converter (“ADC”), comprising:
- an input terminal configured to receive an analog input voltage signal;
- a first ADC circuit coupled to the input terminal and configured to output a first digital value corresponding to the analog input voltage signal;
- a digital-to-analog converter (DAC) circuit coupled to the input terminal and to an output of the first ADC circuit, and configured to output a first analog residue signal corresponding to a difference between the first digital value and the analog input signal;
- a first inverter based residue amplifier configured to receive the first analog residue signal, amplify the first analog residue signal, and output a first amplified residue signal;
- a second ADC stage configured to receive the first amplified residue signal and output a second digital value corresponding to the first amplified analog residue signal;
- and
- a controller coupled to the first and second ADC stages and configured to combine the first and second digital values into a digital output signal representing the analog input voltage signal.
Dependencies are inferred from the claim text.