Analog to digital conversion yielding exponential results
AssigneeLinear Technology Corporation
InventorJoshua Cowan
Life of this patent
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Abstract
A method and system of an analog to digital conversion having an exponential result are provided. An analog input signal is received by the ramp ADC. The analog input signal is converted into an N-bit digital signal having a linear relationship with the analog input signal. An internal gated clock signal is generated based on the received first clock signal. The gated clock signal is used as an input to an M-bit register. An output of the M-bit register is multiplied by a predetermined factor. The product of the multiplication is provided as an input to the M-bit register. The output of the M-bit register provides an M-bit output having an exponential relationship with the analog input signal.
Claims20
An analog to digital converter (ADC) providing an exponential result, comprising:
- a ramp ADC comprising:
- a first input configured to receive an analog input signal;
- a second input configured to receive a first clock signal;
- and
- a logic gate having an output operative to provide an internal gated clock signal based on the received first clock signal;
- and
- an exponential function circuit comprising:
- an M-bit digital register comprising:
- a first input configured to receive the internal gated clock signal of the ramp ADC;
- a second input;
- and
- an output operative to provide an M-bit exponential digital result of the analog input signal;
- and
- an M-bit multiplier circuit comprising:
- a first input coupled to the output of the M-bit digital register;
- a second input operative to receive a reference signal;
- and
- an output coupled to the second input of the M-bit digital register.
A method of providing an analog to digital conversion using a ramp analog to digital converter (ADC), the method comprising:
- receiving an analog input signal by the ramp ADC;
- receiving a first clock signal;
- converting the analog input signal into an N-bit digital signal having a linear relationship with the analog input signal;
- generating an internal gated clock signal based on the received first clock signal;
- using the gated clock signal as an input to an M-bit register;
- multiplying an output of the M-bit register by a predetermined factor;
- and
- providing a product of the multiplication as an input to the M-bit register, wherein the output of the M-bit register provides an M-bit output having an exponential relationship with the analog input signal.
Dependencies are inferred from the claim text.