Analog-to-digital converter, sensor and apparatus
An analog-to-digital converter comprises: an analog-to-digital conversion unit that performs analog-to-digital conversion using ΔΣ modulation on an image signal output from pixels; a setting unit that sets an operating frequency of the analog-to-digital conversion unit; and a generation unit that generates a clock signal having the operating frequency and supplies it to the analog-to-digital conversion unit. The setting unit sets the operating frequency based on at least one of a digital gain to be applied to the signal output from the analog-to-digital conversion unit and a shooting mode.
1 . An analog-to-digital converter comprising:
one or more processors and/or circuitry which function as:
an analog-to-digital conversion unit that performs analog-to-digital conversion using ΔΣ modulation on an image signal output from pixels;
a setting unit that sets an operating frequency of the analog-to-digital conversion unit; and
a generation unit that generates a clock signal having the operating frequency and supplies it to the analog-to-digital conversion unit,
wherein the setting unit sets the operating frequency based on at least one of a digital gain to be applied to the signal output from the analog-to-digital conversion unit and a shooting mode so that bit precision of a signal obtained by applying a digital gain to the image signal which has undergone the analog-to-digital conversion by the analog-to-digital conversion unit is constant regardless of magnitude of the digital gain.
2 . The analog-to-digital converter according to claim 1 , wherein the generation unit divides and multiplies a frequency of a predetermined clock signal to generate the clock signal having the operating frequency.
3 . The analog-to-digital converter according to claim 1 , wherein, given that a predetermined digital gain is M, the setting unit obtains the operating frequency by multiplying a predetermined frequency by M/N in a case where the digital gain to be applied to the image signal is N.
4 . The analog-to-digital converter according to claim 3 , wherein the digital gain is determined based on at least one of ISO sensitivity and a correction method including peripheral illumination correction.
5 . A sensor comprising:
a plurality of pixels; and
an analog-to-digital converter comprising one or more processors and/or circuitry which function as:
an analog-to-digital conversion unit that performs analog-to-digital conversion using ΔΣ modulation on an image signal output from the pixels;
a setting unit that sets an operating frequency of the analog-to-digital conversion unit; and
a generation unit that generates a clock signal having the operating frequency and supplies it to the analog-to-digital conversion unit, and
wherein the setting unit sets the operating frequency based on at least one of a digital gain to be applied to the signal output from the analog-to-digital conversion unit and a shooting mode so that bit precision of a signal obtained by applying a digital gain to the image signal which has undergone the analog-to-digital conversion by the analog-to-digital conversion unit is constant regardless of magnitude of the digital gain.
6 . The sensor according to claim 5 , wherein the generation unit divides and multiplies a frequency of a predetermined clock signal to generate the clock signal having the operating frequency.
7 . The sensor according to claim 5 , wherein, given that a predetermined digital gain is M, the setting unit, in the analog-to-digital converter, obtains the operating frequency by multiplying a predetermined frequency by M/N in a case where the digital gain to be applied to the image signal is N.
8 . The sensor according to claim 5 , wherein, in the analog-to-digital converter, the digital gain is determined based on at least one of ISO sensitivity and a correction method including peripheral illumination correction.
9 . An apparatus comprising:
a sensor that includes:
a plurality of pixels; and
an analog-to-digital converter comprising one or more processors and/or circuitry which function as:
an analog-to-digital conversion unit that performs analog-to-digital conversion using ΔΣ modulation on an image signal output from the pixels;
a setting unit that sets an operating frequency of the analog-to-digital conversion unit; and
a generation unit that generates a clock signal having the operating frequency and supplies it to the analog-to-digital conversion unit; and
a signal processing unit that processes the image signal converted by the analog-to-digital converter,
wherein the setting unit sets the operating frequency based on at least one of a digital gain to be applied to the signal output from the analog-to-digital conversion unit and a shooting mode so that bit precision of a signal obtained by applying a digital gain to the image signal which has undergone the analog-to-digital conversion by the analog-to-digital conversion unit is constant regardless of magnitude of the digital gain.
10 . The apparatus according to claim 9 , wherein the generation unit divides and multiplies a frequency of a predetermined clock signal to generate the clock signal having the operating frequency.
11 . The apparatus according to claim 9 , wherein, given that a predetermined digital gain is M, the setting unit, in the analog-to-digital converter, obtains the operating frequency by multiplying a predetermined frequency by M/N in a case where the digital gain to be applied to the image signal is N.
12 . The apparatus according to claim 9 , wherein, in the analog-to-digital converter, the digital gain is determined based on at least one of ISO sensitivity and a correction method including peripheral illumination correction.