The Eye of Autonomous Driving: A Deep Look at the Front Camera System I

As an effective way to improve travel safety and efficiency, autonomous driving technology has received widespread attention from the automotive and other related industries. As computer vision systems become increasingly mature, front cameras have gradually become an economical, effective and indispensable part of autonomous driving systems.

This series of articles will deeply analyze the modules of the front-view camera system and elaborate on TI's cost-effective star products in each module to facilitate the design and selection of the camera. The entire series will be divided into the following parts for detailed explanation:

Section 1: Power Supply Module

Section 2: Signal Processing Module

Section 3: Interface Module

Section 4: Monitoring and Detection Modules

the battery first , and converts the voltage into an intermediate voltage of 5V/3.3V after a first-level conversion. Then, after a second-level voltage conversion, it is converted into the voltage required by the load. Generally speaking, based on the use and installation scenarios of vehicle-mounted cameras, the front-view camera power supply system generally needs to meet the following three requirements:

(1) As small a volume as possible;

(2) Good thermal performance;

(3) Easy to use and supports subsequent programming expansion.

The following article will focus on these three points and give a detailed introduction to the solutions and star products provided by TI from two aspects: (i) primary (Pre-regulation) power supply; (ii) secondary (POL) power supply.

CMOS sensor power supply

CMOS sensors are very sensitive to noise, especially AVDD power supply ripple noise, which will directly affect the image quality and even cause image distortion. Therefore, the sensor AVDD level is generally powered by an LDO with extremely low output noise . In addition, the EMI and thermal performance of the power supply module have an impact on the quality of the final image. TI provides three reliable CMOS power supply solutions based on the integration level of the solution.

(a) Integrated solution: PMIC (TPS65000-Q1/TPS650320-Q1)

Taking the use of TPS65000-Q1 to power a certain brand of CMOS sensor as an example, TPS65000-Q1 provides two high-precision output LDOs and one high-efficiency Buck, and the input is adjustable, which can meet the needs of different power rails of multiple brands. And the buck frequency is as high as 2.5MHz, which effectively reduces the size of passive components such as inductors , thereby reducing the size of the overall module.

package layout of the camera module . Therefore, it is generally not recommended.

2.2 Processor+Memory Power Supply--PMIC

Since the front camera processor integrates GPU, Safety MCU, image signal processor ISP and Ethernet interface modules, it has a large power demand and different power requirements. TI has customized PMIC power supply solutions for a variety of processors. Take the PMIC chip TPS6594-Q1, which is commonly used in processors, as an example.

• TPS6594-Q1 integrates 5-way Buck and 4-way LDO (one of which is an extremely low-noise LDO);

• It has low EMI noise and good thermal performance, and has fewer peripheral circuits and is easy to use;

• The remaining Buck channels of the PMIC output can also be used to power the memory, which can effectively reduce the size of the overall solution.

TI customizes PMIC power supply solutions for different processors (TDA4/Mobileye Qx/Xilinx/NXP, etc.), as shown in the following table.

Table 3 Processor power supply PMIC selection table

In summary, TI can provide a very complete front-view camera power supply solution with high cost performance, low electromagnetic interference, and the ability to streamline module design, reduce the size of the overall solution while meeting the module's thermal performance, and customize a perfect solution for your front-view camera.