EP-4738710-A1 - SYSTEMS AND METHODS FOR SIGNAL-TO-NOISE RATIO (SNR) OPTIMIZATION USING BIAS CONTROL

EP4738710A1EP 4738710 A1EP4738710 A1EP 4738710A1EP-4738710-A1

Abstract

The subject technology is directed to an apparatus for signal processing. In an embodiment, the apparatus includes a driver configured to receive an input signal comprising a first signal component characterized by a first voltage level and a second signal component characterized by a second voltage level. The apparatus further includes a first circuit configured to adjust the first voltage level by applying a first bias voltage to the first signal component and adjust the second voltage level by applying a second bias voltage to the second signal component. A quantizer is coupled to the driver and configured to generate an output signal based at least on the first voltage level and the second voltage level. This configuration allows for improved signal-to-noise ratio and effective use of the quantizer's dynamic range, enhancing the clarity and accuracy of signal processing in differential systems. There are other embodiments as well.

Inventors

Jara Toro, Matias Ignacio
KHANPOUR, MEHDI
VAKILIAN, KAMBIZ

Assignees

Avago Technologies International Sales Pte. Limited

Dates

Publication Date: 20260506
Application Date: 20251029

Claims (15)

An apparatus comprising: a driver configured to receive an input signal, the input signal comprising a first signal component and a second signal component, the first signal component being characterized by a first voltage level and a first polarity, the second signal component being characterized by a second voltage level and a second polarity, the first polarity being opposite the second polarity; a first circuit coupled to the driver, the first circuit being configured to adjust a first voltage level by applying a first bias voltage to the first signal component and adjust a second voltage level by applying a second bias voltage to the second signal component; and a quantizer coupled to the driver, the quantizer being configured to generate an output signal based at least on the first voltage level and the second voltage level.
The apparatus of claim 1, further comprising a controller coupled to the first circuit, the controller being configured to adjust the first bias voltage and the second bias voltage based at least on the output signal.
The apparatus of claim 2, wherein the controller is configured to store a plurality of bias voltage profiles comprising the first bias voltage and the second bias voltage.
The apparatus of any one of the claims 1 to 3, wherein the first circuit is further configured to calibrate the first bias voltage and the second bias voltage based on a reference signal.
The apparatus of any one of the claims 1 to 4, wherein the first circuit is coupled to the driver through a first node and a second node, the first node is associated with the first signal component, and the second node is associated with the second signal component.
The apparatus of any one of the claims 1 to 5, wherein the quantizer comprises a sampling circuit configured to sample the input signal based on a predetermined interval.
The apparatus of any one of the claims 1 to 6, wherein the first circuit comprises a second circuit configured to receive a first reference voltage and generate the first bias voltage based on the first reference voltage.
The apparatus of claim 7, wherein the first circuit comprises a third circuit configured to receive a second reference voltage and generate the second bias voltage based on the second reference voltage.
The apparatus of any one of the claims 1 to 8, wherein the output signal is associated with a difference between the first voltage level and the second voltage level.
The apparatus of any one of the claims 1 to 9, wherein the output signal comprises a digital signal.
The apparatus of any one of the claims 1 to 10, wherein the first bias voltage is configured to increase the first voltage level and/or the second bias voltage is configured to decrease the second voltage level.
An apparatus comprising: a driver configured to receive an input signal, the input signal comprising a first signal component and a second signal component, the first signal component being characterized by a first voltage level, the second signal component being characterized by a second voltage level; a first circuit coupled to the driver, the first circuit being configured to adjust a first voltage level by applying a first bias voltage to the first signal component and adjust a second voltage level by applying a second bias voltage to the second signal component; and a quantizer coupled to the driver, the quantizer being configured to generate an output signal based at least on the first voltage level and the second voltage level.
The apparatus of claim 12, further comprising at the one of the following features: (A) the apparatus further comprises a controller coupled to the first circuit, the controller being configured to adjust the first bias voltage and the second bias voltage based at least on the output signal; (B) the first bias voltage is configured to increase the first voltage level; (C) the second bias voltage is configured to decrease the second voltage level; (D) the first circuit is coupled to the driver through a first node and a second node, the first node is associated with the first signal component, and the second node is associated with the second signal component; and (E) the output signal is associated with a difference between the first voltage level and the second voltage level.
An apparatus comprising: a driver configured to receive an input signal, the input signal comprising a first signal component and a second signal component, the first signal component being characterized by a first voltage level, the second signal component being characterized by a second voltage level; a first circuit coupled to the driver, the first circuit comprising a second circuit configured to generate a first bias voltage and a third circuit configured to generate a second bias voltage, the first circuit being configured to adjust the first voltage level by applying the first bias voltage to the first signal component and adjust the second voltage level by applying the second bias voltage to the second signal component; and a quantizer coupled to the driver, the quantizer being configured to generate an output signal based at least on the first voltage level and the second voltage level.
The apparatus of claim 14, further comprising at least one of the following features: (A) the apparatus further comprises a controller coupled to the first circuit, the controller being configured to adjust the first bias voltage and the second bias voltage based at least on the output signal; and (B) the output signal is associated with a difference between the first voltage level and the second voltage level.

Description

BACKGROUND OF THE INVENTION Light detection and ranging (LiDAR) systems and optical time-of-flight (ToF) systems are widely used for distance measurement and object detection in various applications such as automotive, robotics, and industrial automation. These systems operate by emitting a pulse of light (e.g., a laser pulse) and measuring the time it takes for the pulse to reflect off a target and return to a detector. High precision and signal clarity are important for accurate distance measurement, particularly in applications where high-resolution mapping is required. In LiDAR and optical ToF systems, the reflected signal from a target may be captured by a photodetector (e.g., a photodiode), which converts the light into an electrical signal. The electrical signal is then processed by a series of circuit components, such as amplifiers and analog-to-digital converters (ADCs), to create a digital representation of the signal. Achieving accurate distance measurements depends on a high signal-to-noise ratio (SNR), which ensures that the signal can be clearly distinguished from any surrounding noise. However, due to factors such as ambient light, sensor noise, and limited ADC dynamic range, maintaining high SNR in these systems can be challenging, often resulting in compromised signal clarity and reduced accuracy in distance measurements. Various approaches for improving SNR in LiDAR and ToF systems have been explored, but they have proven to be insufficient. It is important to recognize the need for new and improved systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS A further understanding of the nature and advantages of particular embodiments may be realized by reference to the remaining portions of the specification and the drawings, in which like reference numerals are used to refer to similar components. In some instances, a sub-label is associated with a reference numeral to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components. Figure 1 is a schematic diagram illustrating a front-end signal processing system, in accordance with various embodiments of the subject technology.Figure 2 is a schematic diagram illustrating the signal input and output of an analog-to-digital converter (ADC), in accordance with various embodiments of the subject technology.Figure 3 is a schematic diagram illustrating the signal input and output of an analog-to-digital converter (ADC), in accordance with various embodiments of the subject technology.Figure 4A is a schematic diagram illustrating a driver circuit with a bias control mechanism, in accordance with various embodiments of the subject technology.Figure 4B is a schematic diagram illustrating the signal input of an analog-to-digital converter (ADC), in accordance with various embodiments of the subject technology.Figure 5 is a schematic diagram illustrating a driver circuit with a bias control mechanism, in accordance with various embodiments of the subject technology. DETAILED DESCRIPTION OF THE INVENTION The subject technology is directed to an apparatus for signal processing. In an embodiment, the apparatus includes a driver configured to receive an input signal comprising a first signal component characterized by a first voltage level and a second signal component characterized by a second voltage level. The apparatus further includes a first circuit configured to adjust the first voltage level by applying a first bias voltage to the first signal component and adjust the second voltage level by applying a second bias voltage to the second signal component. A quantizer is coupled to the driver and configured to generate an output signal based at least on the first voltage level and the second voltage level. This configuration allows for improved signal-to-noise ratio and effective use of the quantizer's dynamic range, enhancing the clarity and accuracy of signal processing in differential systems. There are other embodiments as well. One general aspect includes an apparatus, which comprises a driver configured to receive an input signal, the input signal comprising a first signal component and a second signal component. The first signal component is characterized by a first voltage level and a first polarity. The second signal component is characterized by a second voltage level and a second polarity, the first polarity being opposite the second polarity. The apparatus further comprises a first circuit coupled to the driver. The first circuit is configured to adjust a first voltage level by applying a first bias voltage to the first signal component and adjust a second voltage level by applying a second bias voltage to the second signal component. The apparatus further comprises a quantizer coupled to the driver. The quantizer is configured to generate an output signal based at least on the first voltage level and th