The real-time clock module RA4000CE of the symbol car grade standard provides a precise and reliable clock solution for comprehensive control of automotive power transmission systems

Apr 12,2024
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At present, the level of automotive electrification is getting higher and higher, and a significant development direction is to integrate the engine management system and automatic transmission control system into the comprehensive control (PCM) of the power transmission system. As the core component of automotive power, the use of electronic systems to unify and coordinate data from multiple external sensors and execution links requires electronic systems to have high real-time and reliability, thereby promoting the further development and application of real-time clock modules.

As a real-time clock module manufacturer closely monitoring the automotive industry, EPSON has been tracking the development trends of the automotive industry for a long time and recently launched a real-time clock module RA4000CE using SPI bus interface. This product meets the AEC-Q100 vehicle certification standard, providing automotive electronics manufacturers with higher real-time clock signals and precise and reliable clock solutions for comprehensive control components of automotive power transmission systems, helping manufacturers design products with superior performance.

Figure 1 RA4000CE Product Structure Block Diagram

The real-time clock module with SPI interface and integrated digital temperature compensation has high real-time characteristics. Compared with traditional analog digital compensation clock modules, the RA4000CE real-time clock module adopts digital compensation technology. By detecting temperature and voltage changes inside the module, the analog quantity is converted into digital quantity, and then communication is completed with the computing chip through the SPI interface. Due to the influence of the performance of the devices on both sides of the transmission, the transmission rate of the SPI interface can reach tens of MBps, which is more suitable for point-to-point transmission. For PCM in automotive electronics, it can provide higher density data transmission rate, improve the real-time characteristics of clock signal configuration and interrupt detection.

Figure 2 Frequency stability characteristics of RA4000CE with temperature variation

Assist manufacturers in obtaining vehicle regulations certification, ensuring high reliability and stable operation in harsh automotive environments

Safety is the most important attribute of automobiles, directly related to the safety of people's lives and property. For this reason, the automotive industry strictly implements AEC-Q100 vehicle specification certification, which is more stringent than ordinary industrial products. The purpose is to ensure that cars can operate stably and reliably in various harsh environments, whether in cold or hot weather. RA4000CE is designed and produced strictly in accordance with vehicle regulations. With certification, automotive electronic designers can confidently add the clock module to the BOM list. From Figure 2, it can be seen that the RA4000CE has undergone strict temperature change testing, and its frequency is stable at room temperature. The maximum frequency tolerance at high and low temperatures does not exceed+50.0x10-6. Automotive electronics designers can design the clock system of the product based on these graphic parameters.

Built in rich features with timestamp and wake-up timer functions

The RA4000CE has rich built-in features, including timestamp function, which can record information from 1/1024 second to 1 second, minute, hour, month, and year. It can be triggered by external events such as interruptions, voltage drops, crystal oscillator shutdown, and master level commands. At the same time, the RA4000CE also has a wake-up timer function, with a cycle selection from 976.56uS to 32 years, which can be used as a watchdog or as a time integrator to measure time. Therefore, RA4000CE is not only used as a real-time clock crystal oscillator, but also provides users with supporting design in system functions, thereby improving the overall performance of automotive electronic products.