DC-DC converters with low EMI target automotive infotainment designs
The MAX20073/MAX20074 delivers up to 3A load current from 0.5V to 3.8V. The devices operate from an input voltage range of 2.7V to 5.5V, making them suitable for on-board point-of-load and post-regulation applications. Total output error is less than ±1.5% over load, line, and temperature. The devices feature fixed-frequency PWM mode of operation, with a 2.2MHz switching frequency and combined with Maxim’s spread spectrum oscillator, SYNC IN functionality, forced PWM, skip modes and current-mode architecture can reduce system EMI.
High-frequency operation enables an all-ceramic capacitor design and small external components while the low-resistance on-chip switches ensure high efficiency at heavy loads while minimizing critical inductances, making the layout a much simpler task with respect to discrete solutions.
These backend point-of-load (POL) buck converters send very specific voltages to the many power rails that come with adding advanced modern features so the output voltage accuracy makes them suitable for applications that have these tight processor and memory voltage requirements. As more automotive features are added, the number of power rails continue to increase as well. Each individual power rail is powered from the car battery through a front-end buck converter and often require specific voltage regulation precision requirements.
The devices provide an enable input, spread-spectrum enable input, and active-low RESET output. The output voltage can be preset at the factory to allow customers to achieve ±1.5% output-voltage accuracy without using expensive 0.1% external resistors. In addition, the output voltage can be set to any customer value by using two external resistors at the feedback with 0.5V internal reference. The device offers a fixed 0.85ms soft-start time.
The 3mm x 3mm 10-pin TDFN-EP package reduces overall system footprint, while saving system BOM cost. The output voltage can also be pre-set at the factory to allow ±1.5 percent output-voltage accuracy without the need for expensive 0.1 percent external resistors
“Designers need buck converters that meet today’s increasingly stringent requirements such as small solution size, specific voltage regulation precision, and higher efficiency,” said Warren Tsai, Director of Business Management for the Automotive Business Unit at Maxim Integrated. “The MAX20073 and MAX20074, newest members of the updated family of low-voltage, small POL buck converters meet all their system’s power requirements and pass EMI prerequisites.”
The MAX20073 is available for $1.20 and MAX20074 is available for $1.30 and they operate over the -40 ºC to +125 ºC ambient temperature range. MAX20073EVKIT# and MAX20074EVKIT# evaluation kits are available for $45. Designers are recommended to contact Maxim for pin-compatible ASIL variants.