PMICs for Automotive Camera Modules Built to Meet ISO 26262
The continuing evolution of advanced driver-assistance systems (ADAS) means more onboard cameras in the latest automotive designs. At the same time, the concept of functional safety is taking on greater importance as the failure of even one camera can lead to a serious accident.
For example, in the automotive field, a growing number of companies are promoting functional safety—not only among vehicle manufacturers (OEMs), but Tier 1 electronics equipment suppliers as well, making it an increasingly important requirement worldwide. ROHM Semiconductor, for its part, has gradually expanded its portfolio to include documents required for functional safety in vehicles, and currently features a lineup of more than 1,000 compatible part numbers.
What is ComfySIL?
In 2021, ROHM launched the brand ComfySIL to contribute to the safety, security, and comfort of users and systems through products that support functional safety. As part of the ComfySIL series, these ICs are “FS (Functional Safety) process compliant” (the highest grade), indicating compliance with the ISO 26262 standard.
The ComfySIL brand came about for customers involved in the design of products that support SIL (Safety Integrity Level) in a “Comfy” (comfortable) manner. It also applies to a system’s greater safety, security, and convenience, to which ROHM can contribute through its products.
ISO 26262-Compliant PMICs
This year, ROHM announced the availability of ISO 26262- and ASIL‑B compliant PMICs, the BD868xxMUF-C (BD868C0MUF-C and BD868D0MUF-C) family, for automotive camera modules, which are increasingly being adopted in ADAS.
The PMIC BD868xxMUF-C series consists of primary dc-dc, dual secondary dc-dc, a secondary linear regulator for the CMOS sensor, and an image-sensing power supply. This IC is optimal for camera modules, which require small boards with a small package (the package part number is VQFN20FV3535). This IC has spread-spectrum functionality, providing lower noise-regulated outputs.
Meeting the strict requirements for functional safety allows these latest products to facilitate safety design in next-generation vehicles equipped with ADAS. Moreover, the four power-supply systems (three dc-dc and one LDO) necessary for automotive cameras are integrated into a 3.5- × 3.5-mm package, achieving the industry's smallest size in comparable camera PMICs, according to ROHM.
The PMICs come equipped with an anomaly status notification mechanism, such as abnormal voltage detection and feedback, via I2C. This reduces the number of components by three compared to former solutions, resulting in a 25% smaller mounting area and ultimately contributing to smaller vehicle cameras. (The above 25% is just an example; further miniaturization is possible by optimizing for individual applications.)
At the same time, a wide range of output-voltage and sequence-control settings can be configured to meet the varying requirements of CMOS image sensors from different manufacturers, considerably simplifying development.
In addition to the four models (BD868A0MUF-C, BD868B0MUF-C, BD868C0MUF-C, BD868D0MUF‑C) that comply with both ISO 26262 and ASIL-B, the lineup will include the non-ISO 26262-compliant BD868C1MUF-C for users that don’t require ASIL compliance. Furthermore, ROHM can offer the products based on customer setup requirements, such as output voltages, voltage tolerances, sequencing, and functional-safety requirements.
Applications include rear-view/perimeter cameras, drive recorders, driver monitoring systems, etc.
Samples are available now with mass production scheduled for August 2022. Derivative models (BD868A0MUF-C, BD868B0MUF-C, BD868C1MUF-C) are scheduled to be released in succession as well.