STMicro Unveils New Buck Converter Variants for Enhanced Efficiency Options
STMicroelectronics Unveils New High-Efficiency DC-DC Converters for Streamlined Automotive Designs
STMicroelectronics (ST), a leading innovator in semiconductor solutions, introduces a novel line of synchronous step-down DC-DC converters designed to empower automotive Original Equipment Manufacturers (OEMs) with simplified integration and enhanced efficiency. These new devices cater to diverse application needs, offering both isolated (A6983I) and non-isolated (A6893) variants.
Understanding Isolated vs. Non-Isolated Converters
- Isolated Converters: These converters, exemplified by the A6983I, utilize a transformer to establish electrical separation between the input and output circuitry. This isolation offers additional protection against ground loops and transient voltage spikes, making them suitable for noise-sensitive applications.
- Non-Isolated Converters: Represented by the A6893, these converters lack the transformer, resulting in a generally lower cost and potentially lower power losses. However, they may not be ideal for applications requiring strict noise isolation.
Optimizing Efficiency: Low-Consumption Mode (LCM)
ST prioritizes efficiency in these DC-DC converters. The A6983 incorporates a Low-Consumption Mode (LCM), specifically designed to conserve energy during low-power scenarios. Here's how it works:
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Buck Converter Operation: A buck converter regulates the output voltage by switching on and off, effectively "stepping down" the input voltage while increasing the current delivered to the load. However, this switching process can introduce inefficiencies in the form of power losses and output ripple.
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LCM in Action: When the connected device enters a low-power state, the LCM intelligently skips switching cycles. This power-saving feature is activated when the inductor current falls below a designated threshold (ISKIP) and the output voltage surpasses a specific level (VFB_LCM). By halting unnecessary switching, the LCM minimizes energy consumption while maintaining stable operation.
In LCM variants, the switching cycle is interrupted when VFB exceeds VFB_LCM.
Isolated vs. Non-Isolated Variants: Tailored Performance
The non-isolated A6983 comes in various configurations to address specific requirements:
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A6983C (Low-Consumption Variant): Optimized for light-load applications, where the load current is significantly lower than the converter's nominal rating. The LCM excels in these scenarios, maximizing efficiency.
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A6983N (Low-Noise Variant): This variant prioritizes minimal output ripple by employing forced PWM (Pulse Width Modulation) operation. While this approach ensures low noise, it may lead to slightly lower efficiency compared to the LCM variant.
Block diagram of the A6983.
A6983I: Isolated Efficiency with Transformer Integration
The A6983I offers isolation using a transformer, eliminating the need for an optocoupler typically found in traditional isolated designs. Optocouplers serve to maintain stability by isolating the input and output sides of the converter.
Efficiency comparison of LNM and LCM.
Compact Design, Low Power Consumption
Both the isolated and non-isolated variants of the A6983 boast a space-saving 3 mm x 3 mm QFN package. Additionally, they feature an impressively low quiescent current of 25 µA and a power-saving shutdown mode that consumes less than 2 µA.
Targeting Efficiency in the Electric Vehicle (EV) Market
By introducing the LCM variant with its exceptional light-load operation, ST positions itself competitively within the EV market, where high efficiency is paramount. Similar to Texas Instruments' recent GaN-based DC-DC converter, the A6983 series prioritizes efficiency. ST emphasizes that the A6983's compact package size, coupled with the LCM and LNM options, simplifies integration into EV applications such as traction inverters - a critical component in electric vehicles.
Partner with BonChip Electronics for Your High-Efficiency DC-DC Converter Needs
BonChip Electronics is your trusted distributor for the comprehensive line of STMicroelectronics DC-DC converter solutions, including the innovative A6983 series. Our team of experts possesses in-depth knowledge of ST products and can guide you in selecting the ideal DC-DC converter for your automotive or industrial design. We offer competitive pricing, exceptional service, and fast delivery times. Contact BonChip Electronics today to explore how ST's DC-DC converters can optimize efficiency and simplify integration within your next project.
