Description

The MAX25249/MAX25249B are high-efficiency, four-output PMICs that integrate three DC-DC converters and a high-PSRR LDO, with OV/UV monitoring on all outputs. OUT1 is a 1A high-voltage synchronous step-down converter operating from power over coax or car battery. OUT2 and OUT3 low-voltage synchronous step-down converters operate from OUT1 and provide a 0.8V to 3.9875V output voltage range. OUT2 can deliver 1.2A for high-megapixel cameras and high-speed serializers. OUT3 can deliver 1.2A to power the secondary rails of the imager, serializer, and MCU. OUT4 is a low-voltage, low-noise, high-PSRR LDO for imager power. All buck converters achieve ±1.5% output voltage accuracy over load, line, and temperature range. Overvoltage and undervoltage faults are monitored with ±1.3% accuracy around the set voltage, and errors are communicated through active-low RESET.The devices feature a 2.2MHz fixed-frequency PWM mode for better noise immunity and load-transient response. The high-frequency operation allows for the use of all ceramic capacitors and minimizes external components. The programmable spread-spectrum frequency modulation minimizes radiated electromagnetic emissions. Integrated low-RDS(ON) switches improve efficiency at heavy loads and make layout simpler than discrete solutions.Sequencing through the use of EN23 and EN4 pins and factory-settable output voltages increases flexibility for different image sensors and configurations. Other features include soft-start, overcurrent, and overtemperature protections. The MAX25249/MAX25249B are compliant with ASIL B ratings and are specified for operation over the -40°C to +125°C automotive temperature range.ApplicationsFront/Rear/Surround View Camera