Analog-to-digital converter device and method for operating an analog-to-digital converter device

1 . An analog-to-digital converter device configured to form a digital output signal based on an input current, comprising:

a first analog-to-digital converter unit of a first type; and a second analog-to-digital converter unit of a second type;

wherein the first analog-to-digital converter unit is configured to receive the input current, and, based on the input current, form a first portion of the digital output signal, output a first output current to the second analog-to-digital converter unit, and

wherein the second analog-to-digital converter unit is configured to form a second portion of the digital output signal based on the first output current,

wherein the first analog-to-digital converter unit has at least one converter stage, the at least one converter stage being configured to compare a converter stage input current that can be fed to the at least one converter stage, with a converter stage reference current associated with the at least one converter stage, and, based on the comparison: a) output a converter stage output current, and/or b) output a digital converter stage output signal, and

wherein the at least one converter stage is configured to compare the converter stage input current with the converter stage reference current and, when the converter stage input current is smaller than the converter stage reference current, output the converter stage input current as the converter stage output current, and, when the converter stage input current is greater than or equal to the converter stage reference current, output a difference of the converter stage input current and the converter stage reference current, as the converter stage output current.

2 . The analog-to-digital converter device according to claim 1 , wherein the second type is different from the first type.

3 . The analog-to-digital converter device according to claim 1 , wherein the at least one converter stage includes a first converter stage and a second converter stage, converter stages, wherein the first converter stage is configured to compare a converter stage input current that can be fed to the first converter stage, with a converter stage reference current associated with the first converter stage, and, based on the comparison: a) output a first converter stage output current as an input current for the second converter stage, and/or b) output a first digital converter stage output signal.

4 . The analog-to-digital converter device according to claim 1 , wherein the first analog-to-digital converter unit is configured to output the first portion of the digital output signal as a Gray-coded signal.

5 . The analog-to-digital converter device according to claim 4 , further comprising a transcoding device configured to transcode the Gray-coded signal into a binary-coded signal.

6 . The analog-to-digital converter device according to claim 1 , further comprising a current mirror device configured to output the first output current to the second analog-to-digital converter unit.

7 . The analog-to-digital converter device according to claim 1 , wherein the second analog-to-digital converter unit is configured to provide the second portion of the digital output signal as a unary-coded signal.

8 . The analog-to-digital converter device according to claim 7 , further comprising a transcoding device configured to transcode the unary-coded signal into a binary-coded signal.

9 . The analog-to-digital converter device according to claim 1 , wherein the first analog-to-digital converter unit and the second analog-to-digital converter unit are arranged on a same semiconductor substrate.

10 . The analog-to-digital converter device according to claim 1 , wherein the analog-to-digital converter device is used for at least one of the following elements: a) converting a current into a binary value, b) performing a binary encoding, c) providing a completely current-driven hybrid analog-to-digital converter.

11 . An analog-to-digital converter device configured to form a digital output signal based on an input current, comprising:

a first analog-to-digital converter unit of a first type; and a second analog-to-digital converter unit of a second type;

wherein the first analog-to-digital converter unit is configured to receive the input current, and, based on the input current, form a first portion of the digital output signal output a first output current to the second analog-to-digital converter unit,

wherein the second analog-to-digital converter unit is configured to form a second portion of the digital output signal based on the first output current,

wherein the first analog-to-digital converter unit has at least one converter stage, the at least one converter stage being configured to compare a converter stage input current that can be fed to the at least one converter stage, with a converter stage reference current associated with the at least one converter stage, and, based on the comparison: a) output a converter stage output current, and/or b) output a digital converter stage output signal, and

wherein the at least one converter stage is configured to compare the converter stage input current with the converter stage reference current, and, when the converter stage input current is smaller than the converter stage reference current, output a difference of the converter stage reference current and the converter stage input current as the converter stage output current, and, when the converter stage input current is greater than or equal to the converter stage reference current, output a difference of the converter stage reference current and a difference of the converter stage input current and the converter stage reference current as the converter stage output current.

12 . A method for operating an analog-to-digital converter device which is configured to form a digital output signal based on an input current, wherein the analog-to-digital converter device includes a first analog-to-digital converter unit of a first type and a second analog-to-digital converter unit of a second type, wherein the second type is different from the first type, the method comprising:

receiving, by the first analog-to-digital converter unit, the input current;

forming, by the first analog-to-digital converter unit, based on the input current, a first portion of the digital output signal;

outputting, by the first analog-to-digital converter unit, a first output current to the second analog-to-digital converter unit; and

forming, by the second analog-to-digital converter unit, a second portion of the digital output signal based on the first output current,

wherein the first analog-to-digital converter unit has at least one converter stage, the at least one converter stage being configured to compare a converter stage input current that can be fed to the at least one converter stage, with a converter stage reference current associated with the at least one converter stage, and, based on the comparison: a) output a converter stage output current, and/or b) output a digital converter stage output signal, and

wherein the at least one converter stage is configured to compare the converter stage input current with the converter stage reference current and, when the converter stage input current is smaller than the converter stage reference current, output the converter stage input current as the converter stage output current, and, when the converter stage input current is greater than or equal to the converter stage reference current, output a difference of the converter stage input current and the converter stage reference current, as the converter stage output current.