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RAA271082 has a primary high voltage synchronous buck regulator, two secondary low voltage synchronous buck regulators and a low voltage LDO regulator.
It offers four over-voltage and under-voltage monitors, I2C communications, a configurable general-purpose open-drain I/O pin and a dedicated reset output/fault indicator.
“To meet ASIL B metrics, the RAA271082 includes a second independent reference for over-voltage under-voltage monitors, built-in self-test at power-up, independent over-voltage under-voltage monitoring, and continuous CRC error checking on internal registers and I2C communications,” according to the company. It “simplifies power supply design for automotive camera applications requiring functional safety compliance”.
The front-end dc-dc converter will operate from rails across 4.0 to 42V (≥4.5V to start) and will deliver 2.8 – 5.05V at 1A. Switching is at 2.2MHz with optional pseudo-random spread spectrum.
The other three regulators are typically powered by the first. The two dc-dc converters can be independently set to deliver between 85omV to 3.3V at up to 1A. The LDO is specified to make 2.7 to 3.4V at up to 300mA. All three have programmable sequencing and ramp-up, plus optional output discharge. Under and over-voltage thresholds can be set at ±4, 6, 8 or 12%.
Many options need to be factory-set through OTP (one-time programming, a configuration tool is available), and the I2C interface allows the user to select other options. Most of the OTP options cannot be changed via I2C unless the device is first placed in stand-by mode.
To reset (or NMI) the host MCU, a windowed watchdog timer is provided, which need to be periodically ticked either through the IO pin or by writing to a register.
The device comes in a 4 x 4mm 24pad step-cut QFN with an exposed pad for heat removal. It operates across ambients from -40 to 125°C, and is electrically specified with its junctions across -40 to 150°C.
The company sees it powering image sensors, image signal processors and encoders, either direct from the battery or from power-over-coax. Applications include surround view, satellite, rear view, driver monitor and e-mirror cameras, and, in view of its safety features, also non-camera 16- and 32-bit automotive microcontrollers.
The RAA271082 product page can be found here, and its RTKA271082DE0000BU evaluation board here
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