CN-122001379-A - Differential slope analog-to-digital conversion device

Abstract

A differential slope analog-to-digital conversion device. The first capacitor and the second capacitor sample according to a pair of analog input signals in a sampling time. The slope voltage generating circuit feeds a positive slope voltage to the first capacitor according to a first positive slope and feeds a negative slope voltage to the second capacitor according to a first negative slope in a first feeding time, and feeds a positive slope voltage to the second capacitor according to a second positive slope and feeds a negative slope voltage to the first capacitor according to a second negative slope in a second feeding time, wherein the first and second feeding times are sequentially staggered with the sampling time. The comparison circuit receives the first and second voltages from the first and second capacitors in the first and second feed-in times for comparison to generate a comparison result. The counting circuit counts according to the comparison result to generate a digital output signal.

Inventors

• GAO JIAWEI
• HUANG SHIXIONG

Assignees

• 瑞昱半导体股份有限公司

Dates

Publication Date

20260508

Application Date

20241104

Claims (10)

1. 1. A differential slope analog-to-digital conversion device, comprising: A first capacitor configured to sample according to a pair of analog input signals in a sampling time; a second capacitor configured to sample the analog input signal during the sampling time; A ramp voltage generation circuit configured to: feeding a positive slope voltage to the first capacitor according to a first positive slope and feeding a negative slope voltage to the second capacitor according to a first negative slope in a first feeding time, and The positive slope voltage feeding is carried out on the second capacitor according to a second positive slope in a second feeding time, and the negative slope voltage feeding is carried out on the first capacitor according to a second negative slope, wherein the first feeding time and the second feeding time are sequentially staggered with the sampling time; A comparison circuit configured to receive a first voltage from the first capacitor and a second voltage from the second capacitor for comparison in the first and second feed times to generate a comparison result, and A counting circuit configured to count according to the comparison result to generate a digital output signal.
2. 2. The differential slope analog-to-digital conversion apparatus of claim 1, further comprising: a first input switch configured to input a first analog input signal of the analog input signal to a first end of the first capacitor during the sampling time, wherein the first end of the first capacitor is electrically coupled to the ramp voltage generating circuit during the first feeding time and the second feeding time; A second input switch configured to input a second analog input signal of the analog input signal to a second end of the first capacitor during the sampling time, wherein the second end of the first capacitor is electrically coupled to the comparison circuit during the first feeding time and the second feeding time; A third input switch configured to input the second analog input signal to a first end of the second capacitor during the sampling time, wherein the first end of the second capacitor is electrically coupled to the ramp voltage generating circuit during the first feeding time and the second feeding time, and A fourth input switch configured to input the first analog input signal to a second end of the second capacitor during the sampling time, wherein the second end of the second capacitor is electrically coupled to the comparison circuit during the first feeding time and the second feeding time.
3. 3. The differential slope analog-to-digital conversion apparatus of claim 1, wherein the ramp voltage generating circuit further comprises: a first current feed-in circuit configured to electrically couple with the first capacitor only during the first feed-in time, so as to feed-in the positive slope voltage to the first capacitor feed-in current; a second current feed-in circuit configured to electrically couple with the second capacitor only during the second feed-in time, so as to feed-in the positive slope voltage to the second capacitor feed-in current; A first current drawing circuit electrically coupled to the first capacitor for drawing current from the first capacitor for feeding the negative slope voltage only during the second feeding time, and A second current drawing circuit is configured to be electrically coupled to the second capacitor only during the first feeding time to draw current from the second capacitor for the negative slope voltage feeding.
4. 4. The differential slope analog-to-digital conversion apparatus of claim 3, further comprising: A first feed-in switch configured to electrically couple the first current feed-in circuit to a first connection point only during the first feed-in time; A second feed-in switch configured to electrically couple the second current feed-in circuit to a second connection point only during the second feed-in time; a first current drawing switch configured to electrically couple the first current drawing circuit to the first connection point only during the second feeding time; a second current drawing switch configured to electrically couple the second current drawing circuit to the second connection point only during the first feeding time; A first connection switch configured to electrically couple the first connection point to a first end of the first capacitor during the first feeding time and the second feeding time, and The second connection switch is configured to electrically couple the second connection point to a first end of the second capacitor during the first feeding time and the second feeding time.
5. 5. The differential slope analog-to-digital conversion apparatus of claim 4, further comprising: a first comparison switch configured to electrically couple the comparison circuit to a second end of the first capacitor during the first and second feeding times, and The second comparison switch is configured to electrically couple the comparison circuit to a second end of the second capacitor during the first feed-in time and the second feed-in time.
6. 6. The differential slope analog-to-digital conversion apparatus of claim 1, wherein the pair of analog input signals are a pair of ac signals.
7. 7. The differential slope analog-to-digital conversion apparatus of claim 1, wherein the analog input signal comprises an ac signal and a dc signal.
8. 8. The differential slope analog-to-digital conversion apparatus of claim 1, wherein the comparison circuit performs the comparison by subtracting the first voltage and the second voltage to equivalently perform the voltage adjustment according to a first slope subtracted from the first positive slope and the first negative slope at the first feed-in time, and to equivalently perform the voltage adjustment according to a second slope subtracted from the second negative slope and the second positive slope at the second feed-in time.
9. 9. A differential slope analog-to-digital conversion method, comprising: sampling a first capacitor according to a pair of analog input signals in a sampling time; a second capacitor is used for sampling according to the analog input signal in the sampling time; enabling a ramp voltage generating circuit to feed a positive slope voltage to the first capacitor according to a first positive slope and feed a negative slope voltage to the second capacitor according to a first negative slope in a first feeding time; The slope voltage generating circuit feeds the positive slope voltage to the second capacitor according to a second positive slope and feeds the negative slope voltage to the first capacitor according to a second negative slope in a second feeding time, wherein the first feeding time and the second feeding time are sequentially staggered with the sampling time; a comparison circuit for comparing a first voltage from the first capacitor with a second voltage from the second capacitor in the first and second feeding times to generate a comparison result, and A counting circuit is made to count according to the comparison result to generate a digital output signal.
10. 10. The differential motion type as claimed in claim 9 the slope analog-to-digital conversion method is provided, further comprises: The comparison circuit is made to compare by subtracting the first voltage and the second voltage to equivalently perform voltage adjustment according to a first slope subtracted from the first positive slope and the first negative slope at the first feeding time, and equivalently performing voltage adjustment according to a second slope subtracted from the second negative slope and the second positive slope at the second feeding time.

Description

Differential slope analog-to-digital conversion device Technical Field The present invention relates to analog-to-digital conversion, and more particularly, to a differential slope analog-to-digital conversion device. Background An analog-to-digital converter is a device for converting a continuous signal in analog form into a discrete signal in digital form. The analog-to-digital converter may be implemented in various ways, and a slope (ADC) analog-to-digital converter (analog-to-digital conversion) is one of them, and generates a digital signal by comparing and counting an input signal with a ramp signal. However, in the slope analog-to-digital conversion device, if the time required for the ramp signal to climb to a specific level is too short, the required slope will rise greatly, thereby increasing the design complexity of the ramp signal generating circuit. Disclosure of Invention In view of the above problems, it is an object of the present invention to provide a differential slope analog-to-digital conversion device for improving the prior art. The invention comprises a differential slope analog-to-digital conversion device, which comprises a first capacitor, a second capacitor, a ramp (ramp) voltage generating circuit and a comparison circuit. The first capacitor is configured to sample according to a pair of analog input signals during a sampling time. The second capacitor is configured to sample the analog input signal during a sampling time. The ramp voltage generating circuit is configured to perform positive slope voltage feeding on the first capacitor according to a first positive slope and negative slope voltage feeding on the second capacitor according to a first negative slope in a first feeding time, and perform positive slope voltage feeding on the second capacitor according to a second positive slope and negative slope voltage feeding on the first capacitor according to a second negative slope in a second feeding time, wherein the first feeding time and the second feeding time are sequentially staggered with the sampling time. The comparison circuit is configured to receive a first voltage from the first capacitor and a second voltage from the second capacitor for comparison in the first feed-in time and the second feed-in time to generate a comparison result. The counting circuit is configured to count according to the comparison result to generate a digital output signal. The invention further comprises a differential slope analog-to-digital conversion method, which comprises the steps of sampling a first capacitor according to a pair of analog input signals in a sampling time, sampling a second capacitor according to the pair of analog input signals in the sampling time, enabling a slope voltage generating circuit to feed a positive slope voltage to the first capacitor according to a first positive slope and feed a negative slope voltage to the second capacitor according to a first negative slope in the first feeding time, enabling the slope voltage generating circuit to feed a positive slope voltage to the second capacitor according to a second positive slope and feed a negative slope voltage to the first capacitor according to a second negative slope in the second feeding time, enabling a comparison circuit to receive a first voltage from the first capacitor and a second voltage from the second capacitor in the first feeding time and the second feeding time in sequence, and enabling a counting circuit to count according to the comparison result so as to generate a digital output signal. The features, implementation and functions of the present invention are described in detail below with reference to the preferred embodiments shown in the drawings. Drawings FIGS. 1A-1C are diagrams showing a differential slope analog-to-digital converter with different operation time according to one embodiment of the present invention; FIG. 2 is a diagram showing waveforms of signals related to the operation of the differential slope analog-to-digital conversion apparatus of FIGS. 1A-1C according to one embodiment of the present invention; FIG. 3 is a waveform diagram showing the first connection voltage of the first connection point, the second connection voltage of the second connection point, the first voltage of the second end of the first capacitor, and the second voltage of the second end of the second capacitor of FIGS. 1A-1C according to one embodiment of the present invention FIG. 4 is a flow chart of a differential slope analog-to-digital conversion method according to an embodiment of the invention. Detailed Description One objective of the present invention is to provide a differential slope analog-to-digital conversion device, which uses differential operation to make the two ends of the comparison circuit receive the slope voltages with opposite slopes, so as to achieve the effect of making the analog input signals approach each other under the increase of the equivalent slope, and