US 2025/0030409 A1Published application

Signal conversion device and circuit system using the same

AssigneeNuvoton Technology Corporation

InventorsYEH-TAI HUNG, CHING-YEN CHIU, CHUNG MING HSIEH

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Abstract

A signal conversion device for converting a single-ended input voltage into a differential input voltage having a positive input voltage and a negative input voltage is provided. During a sampling phase, a holding phase, and a common-mode voltage generation phase, a capacitor related to the positive input voltage is electrically connected to the single-ended input voltage, and a capacitor related to the negative input voltage is electrically connected to a preset voltage. During a single-ended to differential phase, the capacitor related to the positive input voltage is electrically connected to the preset voltage, and the capacitor related to the negative input voltage is electrically connected to the single-ended input voltage. Hence, the common-mode voltage is not related to a capacitance ratio, and the capacitors does not need to be designed as switching capacitors with multiple switches. No complex control is required, and the parasitic effect of the circuit can be reduced.

Claims18

Dependent claims

A signal conversion device for converting a single-ended input voltage into a differential input voltage having a positive input voltage and a negative input voltage, the signal conversion device comprising:

a first voltage selector having a first terminal, and configured to select one of the single-ended input voltage and a preset voltage as a first voltage output at the first terminal;
a second voltage selector having a second terminal, and configured to select one of the single-ended input voltage and the preset voltage as a second voltage output at the second terminal, wherein the first voltage is different from the second voltage;
a third voltage selector having a third terminal, and configured to select a system voltage or a ground voltage as a third voltage output at the third terminal;
a system voltage equalizer having a fourth terminal and a fifth terminal, and configured to selectively electrically connect the fourth terminal and the fifth terminal to the system voltage;
a first capacitor electrically connected between the first terminal and the fourth terminal;
a second capacitor electrically connected between the third terminal and the fourth terminal;
a third capacitor electrically connected between the ground voltage and the fourth terminal;
a fourth capacitor electrically connected between the second terminal and the fifth terminal;
a fifth capacitor electrically connected between the third terminal and the fifth terminal;
and
a sixth capacitor electrically connected between the ground voltage and the fifth terminal,
wherein the fourth terminal is used to output the positive input voltage in a single-ended to differential conversion phase, and the fifth terminal is used to output the negative input voltage in the single-ended to differential conversion phase.

9 more elements

A circuit system comprising:

a signal conversion device for converting a single-ended input voltage into a differential input voltage having a positive input voltage and a negative input voltage, wherein the signal conversion device comprises:
a first voltage selector having a first terminal, and configured to select one of the single-ended input voltage and a preset voltage as a first voltage output at the first terminal;
a second voltage selector having a second terminal, and configured to select one of the single-ended input voltage and the preset voltage as a second voltage output at the second terminal, wherein the first voltage is different from the second voltage;
a third voltage selector having a third terminal, and configured to select a system voltage or a ground voltage as a third voltage output at the third terminal;
a system voltage equalizer having a fourth terminal and a fifth terminal, and configured to selectively electrically connect the fourth terminal and the fifth terminal to the system voltage
a first capacitor electrically connected between the first terminal and the fourth terminal;
a second capacitor electrically connected between the third terminal and the fourth terminal;
a third capacitor electrically connected between the ground voltage and the fourth terminal;
a fourth capacitor electrically connected between the second terminal and the fifth terminal;
a fifth capacitor electrically connected between the third terminal and the fifth terminal;
and
a sixth capacitor electrically connected between the ground voltage and the fifth terminal,
wherein the fourth terminal is used to output the positive input voltage in a single-ended to differential conversion phase, and the fifth terminal is used to output the negative input voltage in the single-ended to differential conversion phase;
and
a functional circuit electrically connected to the signal conversion device to receive the differential input voltage and perform a specific function based on it.

12 more elements

Dependencies are inferred from the claim text.