ROHM Introduces SerDes ICs and PMICs Aimed at Automotive Cameras

ROHMs new BU18xMxx-C series and its BD86852MUF-C are serializer/deserializers (SerDes) and a power management IC (PMIC) that both utilize a spread spectrum function to reduce EMI.

The PMIC and the two SerDes ICs are available in VQFN24FV4040, VQFN32FV050, and HTQFP64BV packages. Image courtesy of ROHM

 

The BD86852MUF-C PMIC is purposed to manage the power supply systems of CMOS image sensors, controlling voltage settings, and managing sequence control.  Working with devices from all major manufacturers, ROHM asserts that this single-chip solution with its high level of integration reduces board space requirements by 41%

 

The BU18TMxx-C Serializer and the BU18RMxx-C Deserializer ICs

The BU18xMxx-C serializer and deserializer ICs both optimize the data transmission rates based on video resolution. This innovation makes it possible to attain a power reduction of 27% when compared to competitive solutions. Additionally, the devices’ spread spectrum function reduces peak EMI by 20dB. The units also employ a video sticking detection function to detect frozen images, improving the reliability of ADAS systems.

As illustrated below, the device also includes an image freeze detection function. Its function is illustrated below:

Image courtesy of ROHM

The function first involves verifying correct image transmission. It does so by comparing the MIPI CRC value from the CMOS image sensor to that of the deserializer. To detect stuck images, it also compares the frame CRC value of the camera image with the previous and next values in the serializer. In this manner, the driver is alerted to ADAS malfunctions.

All members of the BU18xMxx-C series are compatible with STP, Coaxial on POE cables. They adhere to the Clockless Linke-BD (CLL-BD) transmission standard. The three series members are summarized below:

 

	Function	Supply Voltage	Input Specification	Output Specification
BU18TM41-C	Serializer	1.8V	MIPI CSI-2 (1.5Gbpsx4)	CLL-BD (3.6Gbpsx1)
BU18RM41-C	Deserializer	1.8V	CLL-BD (3.6Gbpsx1)	MIPI CSI-2 (1.5Gbpsx4)
BU18RM84-C	4-in-1 Deserializer	1.2/1.8V	CLL-BD (3.6Gbpsx4)	MIPI CSI-2 (1.7Gbpsx8)

 

BD86852MUF-C Camera PMIC

Depending on their manufacturer, CMOS image sensors need different drive voltage settings and sequence controls. The BD86852MUF-C is equipped with pins for setting the sequence control and drive voltage to satisfy their varied requirements. sensors.

The BD86852MUF-C employs an external LDO to supply power to the CMOS image sensor, which also allows a shorter connection between it and its source of power. This serves to decrease the amount of disturbance noise in the power supply line, leading to increased stability.

This also results in suppressing the generation of heat and enables a power conversion efficiency of 78.6%, which ROHM asserts to be 4% greater than competing devices.

The BD86852MUF-C operates from a supply voltage ranging from 4 to 18V and switches at 2.2 MHz.

• One version features Primary, Secondary1, and Secondary2 output voltages of 3.3 or 3.9V, 1.1 or 1.2V and 1.8V, respectively.
• A second version offers Primary, Secondary1 and Secondary2 output voltages of 2V, 1V, and 1V, respectively.

 

Physical

• The BD86852MUF-C and all members of the BU18xMxx-C series operate over a -40 to +105℃ temperature range.

 

Regulatory

• Both the BD86852MUF-C and the BU18xMxx-C SerDes series are AEC-Q100 qualified.

 

Getting to Market Faster

The BD86852-TSB-001 is an evaluation board for the BD86852MUF-C PMIC, which will serve to familiarize designers with the unit’s functions.

 

Featured image used courtesy of ROHM