Four-Output Mini PMICs for Camera Applications

The MAX25249C/MAX25249D are high-efficiency, fouroutput 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 stepdown converter operating from power over coax or car battery. The 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 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 factorysettable output voltages increases flexibility for different image sensors and configurations. Other features include soft-start, overcurrent, and overtemperature protections. The MAX25249C/MAX25249D are compliant with ASIL B ratings and are specified for operation over the -40°C to +125°C automotive temperature range.

APPLICATIONS

* Surround-View Cameras

* Rear-View Cameras

* Multiple Functions for Small Size

* 1A Synchronous High-Voltage Buck Converter

* Input Voltage Range 5V to 36V

* 3V to 4V in 50mV Steps

* 5V Fixed Output Voltage

* Two Synchronous Low-Voltage Buck Converters

* OUT2 and OUT3 Provide up to 1.2A

* 0.8V to 3.9875V in 12.5mV Steps

* LDO for Camera Sensor; 50dB at 1kHz

* 2.2MHz Operation

* RESET Output – Push Pull or Open Drain