STMicroelectronics’ Automotive-Qualified Step-Down Synchronous DC/DC Converters with Enhanced Features

STMicroelectronics has launched new automotive-qualified step-down synchronous DC/DC converters tailored for applications like body electronics, audio systems, and inverter gate drivers. The A6983 converters offer six non-isolated step-down converters in low-consumption and low-noise configurations, along with the A6983I isolated buck converter. These monolithic devices feature compensation circuitry on-chip, reducing the need for external components. The non-isolated A6983 converters can deliver up to 3A load current with 88% typical efficiency at full load. The low-consumption variants (A6983C) are optimized for light-load operation, while the low-noise A6983N variants ensure constant switching frequency and minimize output ripple. Both types offer output voltage options of 3.3V, 5.0V, and adjustable from 0.85V to VIN.

The A6983I is a 10W iso-buck converter with primary-side regulation, eliminating the need for an optocoupler. It is suitable for use as an isolated gate driver for IGBTs or SiC MOSFETs in traction inverters and on-board chargers, allowing accurate adjustment of the primary output voltage. All variants feature low quiescent operating current, power-saving shutdown mode, wide input-voltage range, load-dump tolerance, output overvoltage protection, thermal protection, and internal soft start. Optional spread-spectrum operation helps reduce electromagnetic interference, and a power-good pin enables power sequencing. The A6983I and A6983 allow synchronization to an external clock.

Features:

• AEC-Q100 qualification
• Wide operating temperature range (-40 °C to +150 °C for Tj)
• Input voltage range: 3.5 V to 38 V
• Load dump tolerance up to 40 V
• Output voltage range: 0.85 V to VIN, with fixed versions at 3.3 V and 5 V
• Operating quiescent current: 25 μA
• Internal compensation network
• Output overvoltage protection and sequencing
• High voltage VIN compatible enable
• Programmable switching frequency
• Synchronization to external clock for LNM devices
• QFN16 (3 x 3 mm) package

Applications:

• Automotive systems
• Car audio
• Parking applications
• Low noise applications

Availability: 

The converters are available in 3mm x 3mm QFN16 format, priced at $1.75 for A6983 and $1.81 for A6983I, with free samples and evaluation boards provided.