ROHM develops SerDes for in-vehicle multi-screen displays that simplifies video transmission paths

ROHM Develops "BU18xx82-M" SerDes for Automotive Multi-Displays that Simplifies Video Transmission Path

Supports Full HD resolution products and supports functional safety through industry-leading end-to-end data monitoring capabilities

ROHM (headquartered in Kyoto, Japan), a world-renowned semiconductor manufacturer, has developed a SerDes IC*1 (serializer: BU18TL82-M, deserializer: BU18RL82-M) that supports full HD resolution (1,980×1,080 pixels) for the automotive display field that is trending towards multi-screen displays.

In recent years, with the popularity of electronic rearview mirrors and LCD instrument panels, the number of displays installed in each car has increased, and the video transmission path has become more complicated, which will inevitably lead to increased system costs and failure risks. Therefore, simplifying the video transmission path has always been an urgent issue to be solved. In addition, since problems such as image freezes on electronic mirrors and indicator icons not lighting up on instrument panels may cause serious accidents, it is also very important to incorporate functional safety design.

The new product solves these problems through daisy chain connection and end-to-end data monitoring functions. In addition, it inherits the low power consumption and low noise characteristics of the SerDes IC "BU18xMxx-C" for automotive camera modules, which has been mass-produced since June 2021, and is very suitable for next-generation automotive displays with increasingly complex video transmission paths.

Ordinary SerDes ICs require a serializer and deserializer to be connected in pairs to transmit video, but ROHM's new product can connect the deserializer "BU18RL82-M" in a daisy-chain manner, so video can be transmitted to multiple paths through a single serializer. Since the number of connectors and cables can be reduced, the video transmission path can be simplified, which helps reduce the system cost and failure risk of application products. In addition, as a SerDes IC that supports full HD resolution, the new product has the function of monitoring whether the video data has been transmitted correctly end-to-end*3 (from SoC to display) by comparing the CRC*2 value, which helps to improve the functional safety of application products.

Samples of the new product have been available for sale since July 2022 (sample price is 1,500 yen/piece, excluding tax), and mass production is expected to begin in September 2022 at a temporary capacity of 200,000 units per month. The production base for the early stages is ROHM Hamamatsu Co., Ltd. (Hamamatsu City, Japan), and the production base for the later stages is ROHM Electronics Philippines, Inc. (Philippines).

ROHM will continue to develop ICs that reduce mounting area and power consumption while improving reliability, contributing to the advancement of automotive technology and the improvement of safety.

＜Product Lineup＞

The new product "BU18xx82-M" complies with the automotive electronics reliability standard AEC-Q100, ensuring the high reliability required for in-vehicle applications. In addition, the serializer "BU18TL82-M" supports the input interfaces OpenLDI and MIPI-DSI, making it suitable for a variety of SoCs.

＜About ROHM's SerDes IC＞

The basic characteristics of ROHM's SerDes ICs are low power consumption and low noise. Since June 2021, ROHM has begun mass production of the first batch of SerDes IC products with these characteristics - the SerDes IC "BU18xMxx-C" for automotive camera modules.

・Basic features ①: Low power consumption

The new product has a function to optimize the transmission rate according to the resolution, so that data of the required resolution can be transmitted with less power, which will greatly help reduce the power consumption of application products.

・Basic feature ②: Low noise

The new product has a function that optimizes the transmission rate, thereby reducing noise by adjusting the noise peak. In addition, it also has a spread spectrum*4 function that can significantly reduce noise, helping to reduce the man-hours of noise reduction design.

＜Terminology＞

*1) SerDes IC

A generic term for two ICs used in pairs to convert communication methods for high-speed data transmission. A serializer is used to convert data into a form that is easy to transmit at high speed (convert a parallel bus into a serial bus), and a deserializer is used to convert the transmitted data into its original format (convert a serial bus into a parallel bus).

*2) CRC (Cyclic Redundancy Check)

A method used to confirm whether data transmission and recording are performed correctly. In high-speed interfaces such as SerDes, a CRC value is added when sending data and processed at the receiving end to confirm whether the data has been transmitted correctly.

*3) End to End

In the IT field, it mainly refers to terms related to transmission paths such as "from one end to the other" and "at both ends of the communication path".

*4) Spread spectrum function

This function does not fix the switching frequency but varies it within a certain range, thereby spreading the noise energy over a certain frequency width. This can reduce EMI noise by reducing the noise peak.