Automotive electronics mixed signal test solution

The increasing number of digital and serial signals has led to a sharp increase in the complexity of automotive electronics. It is becoming increasingly necessary to use only one instrument to complete the testing of digital and analog signals.

The complexity of automotive electronics is increasing with the increasing application of digital circuits and serial signals, and it is becoming increasingly important to determine the best test tool. Today, engineers have to process and analyze a large number of mixed technology signals that include a combination of digital and analog technologies, which requires the ability to use a single instrument to implement and complete the testing and analysis of digital and analog signals.

1. Test requirements for mixed signals in automotive electronic systems

The complexity of automotive electronics is increasing with the increasing application of digital circuits and serial signals, and it is becoming increasingly important to determine the best test tool. Today, engineers have to process and analyze a large number of mixed technology signals that include a combination of digital and analog technologies, which requires the ability to use a single instrument to implement and complete the testing and analysis of digital and analog signals.

Traditionally, this kind of mixed signal is usually tested with independent oscilloscopes and logic analyzers, which undoubtedly increases the complexity of the test process. Therefore, this method is not practical. In response to this, Tektronix has launched a hybrid oscilloscope that can meet the requirements of mixed signal and serial protocol testing. It can capture and analyze analog and digital signals on one instrument at the same time. More importantly, it can analyze the time relationship between digital and analog signals at the same time, which truly improves the test environment and tools of engineers, allowing engineers to easily deal with more complex mixed signal designs.

A typical ECU mixed signal system is shown in the figure below, which includes mixed signal devices such as AD/DA/MCU.

Figure 1: Basic components of ECU

2. Mixed signal test solution and configuration

Tektronix's mixed signal test solutions provide a wide range of options and configurations. Multiple series of mixed signal test platforms can meet the testing needs of different applications and occasions, making the testing of automotive electronic systems and components simple, efficient, and reliable. Tektronix's mixed signal test platforms are as follows:

(1) For analog signal testing, Tektronix can provide superior hardware performance to ensure the integrity detection, capture and analysis of analog signals. The main performance specifications are as follows:

Table 1: Platform performance specifications

The displayed analog signal is as follows:

Figure 2: Analog signal diagram

(2) Testing of digital signals The detection and capture of digital signals must be able to meet the increasingly fast digital signal testing requirements. Tektronix's MagniVu high-speed digital acquisition technology can improve the timing resolution of digital signals to 60.6ps. The digital channel of the mixed signal test system has the following hardware features:

Table 2: Digital channel characteristics of mixed signal test system

Channel-independent threshold settings make it easy to complete mixed signal and mixed logic tests. [page]

Figure 3: Threshold setting

(3) Testing of serial protocols

Tektronix's mixed signal test platform supports the following standard protocol triggering and decoding analysis.

A: Low-speed serial protocols: I2C, SPI, CAN, LIN, FlexRay, RS-232/422/485/UART, I2S/LJ/RJ/TDM, MIL-STD-1553

B: High-speed protocols: LAN, USB, DDR

3. Characteristics and advantages of mixed signals

Tektronix's mixed signal analysis instruments can effectively solve the problem of synchronous analysis of multiple types of signals. The typical analysis interface is as follows:

Figure 4: Typical analysis interface

Such analytical capabilities can make system analysis and testing of automotive electronics simple and efficient, allowing engineers to get rid of complex instrument usage issues and focus on product research and development.

Tektronix's mixed-signal instruments all provide waveform navigation and search functions, which can help engineers quickly locate and find the focus in a large amount of information, especially bus analysis.

Figure 5: Bus analysis

Waveform search and marking can simplify the analysis of waveform details

A: Determine the search criteria

(1) Serial data packet content

(2) Parallel Data

(3) Common trigger combinations

B: Wave Inspector marks each event as it occurs

C: Use the arrow buttons to jump from one event to another

This fast tool allows you to search and analyze the entire waveform data at any time.

Therefore, the mixed signal test platform of Tektronix can reflect the following characteristics for the research and development and testing of automotive electronics:

(1) Advanced hardware platform supports 100MHz-2GHz signal capture

(2) The industry's highest storage length: 20M

(3) Can decode 16/4 bus data at the same time

(4) Wave Inspector automatic search and marking functions are convenient and fast

(5) Support decoding and analysis of various standards: CAN/LIN, FlexRay, MOST, etc.