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Streamlined Integration for Automotive Electronics: Introducing STMicroelectronics’ New Step-Down DC/DC Converters
STMicroelectronics has unveiled new automotive-qualified step-down synchronous DC/DC converters designed to save space and simplify integration in various automotive applications, including body electronics, audio systems, and inverter gate drivers.
Flexible Design for Diverse Applications
The A6983 series offers a versatile range of design options, featuring six non-isolated step-down converters available in both low-consumption and low-noise configurations, as well as the A6983I isolated buck converter. These highly integrated monolithic devices incorporate on-chip compensation circuitry, requiring minimal external components such as filtering, feedback, and a transformer for the A6983I.
High Efficiency and Optimized Performance
The non-isolated A6983 converters deliver up to 3A load current with 88% typical efficiency at full load. The low-consumption variants (A6983C) are engineered for high efficiency and low output ripple during light-load operation, reducing battery drain in systems active while parked. The low-noise variants (A6983N) maintain a constant switching frequency to minimize output ripple across the load range, making them ideal for audio-system power supplies. These converters offer output voltage options of 3.3V, 5.0V, and adjustable outputs from 0.85V to VIN.
Advanced Features for Isolated Applications
The A6983I is a 10W isolated buck converter with primary-side regulation, eliminating the need for an optocoupler. This makes it perfect for isolated gate driver applications for IGBTs or silicon-carbide (SiC) MOSFETs in traction inverters and on-board chargers (OBCs). It allows precise adjustment of the primary output voltage, with the transformer turns ratio determining the secondary voltage.
Robust and Reliable
All variants feature a low quiescent current of 25µA and a power-saving shutdown mode that consumes less than 2µA. They support an input-voltage range from 3.5V to 38V and can withstand load-dump conditions up to 40V, ensuring resilience against supply bus transients. Additional protections include output overvoltage protection, thermal protection, and an internal soft start. Optional spread-spectrum operation helps reduce electromagnetic interference (EMI), essential for noise-sensitive applications, and a power-good pin supports power sequencing. Both the A6983I and A6983 can synchronize with an external clock.
Compact and Cost-Effective
Housed in a compact 3mm x 3mm QFN16 package, these converters are designed for space-constrained applications. Pricing starts at $1.75 for the A6983 and $1.81 for the A6983I for orders of 1000 pieces. Free samples are available through the ST eStore. Additionally, the STEVAL-A6983CV1 and STEVAL-A6983NV1 evaluation boards for the A6983 series and STEVAL-L6983IV for the A6983I are available to facilitate rapid development and expedite project timelines.
STMicroelectronics’ new DC/DC converters provide a streamlined, efficient solution for integrating advanced power management in automotive electronics, driving innovation and performance in next-generation vehicles.
