Consumers demand increasingly powerful yet compact electronic devices in today’s fast-paced world. From smartphones and laptops to wearable technology, these devices must deliver high performance while fitting into our increasingly mobile lifestyles. Engineers constantly seek innovative solutions to meet these demands and enhance device efficiency, battery life, and overall user experience.
Advancements in battery technology have developed smaller, lighter batteries with higher power density, such as lithium-ion (Li-ion) and Li-ion polymer (LiPo) batteries. Leveraging these advances necessitates miniaturizing associated circuitry to handle power demands efficiently. Components, such as Schottky rectifiers, are key in achieving this, as they effectively enhance power management and dissipate heat. Balancing power delivery relative to size is essential for maintaining both performance and reliability in modern electronics.
The pursuit of efficiency improvements in developing new consumer devices often involves only modest, incremental enhancements. Still, these improvements translate to consumer benefits like smaller, higher-performance products and give manufacturers a competitive edge.
Consumers expect their wearables, including smartwatches, fitness trackers, earbuds, Bluetooth headsets, and VR headsets, to continue to get smaller and lighter while delivering steadily improving performance. Meeting consumer expectations demands high power density, compact size, lightweight, and extended battery run times. These requirements drive the need for innovative solutions in circuitry, batteries, and advanced component packaging.
Component packaging is crucial in determining device size, performance, and reliability. Traditional packaging is bulky and poses thermal challenges. In contrast, chip-scale packaging (CSP) minimizes the package size to nearly that of the chip itself, providing several benefits:
- Reduced footprint and profile: CSP occupies significantly less PCB space.
- Reduced weight: CSP is significantly lighter.
- Reduced environmental impact: Totally lead-free (Pb-free) and fully compliant with RoHS 3.0 standards.
- Improved thermal dissipation: Heat is efficiently directed through pads on the chip’s underside into the PCB, reducing thermal resistance and cooling budget.
- Enhanced performance and reliability: CSP components deliver higher power densities at cooler temperatures due to superior heat management.
To meet the needs of product designers, such as those for wearables, Diodes Incorporated has introduced a 2A Schottky trench rectifier, the SDT2U60CP3, packaged in the X3-DSN1406-2. It occupies only 3.4% of the PCB area required by larger SMB-packaged Schottky rectifier counterparts, significantly reducing the PCB space requirement. Weighing in at a mere 1mg, it is also 99% lighter, contributing to a lightweight design.
One important consideration when selecting a Schottky rectifier is the forward voltage drop (VF). This is especially important for blocking or reverse polarity protection circuits (Figure 1).
In these configurations, the rectifier protects against accidental reverse supply connection or blocking, for example, to prevent reverse battery discharge in portable applications. When used in wearable earbuds, the rectifier can prevent unintentional reverse polarity connections in the charging dock or prevent accidental battery discharge through the earbud charging pads.
When forward-biased, the rectifier conducts passing current to the load. However, the VF needs to be low enough that it does not have a discernible impact on the circuit, especially in mobile applications running on only a few volts.
A small value for VF is also important because it directly relates to power loss. The value is multiplied by the passing current to determine the loss in power dissipated as heat. This falls into the waste element mentioned earlier in the article. The SDT2U60CP3 achieves a typical VF of 0.51V, which is exceptionally low for its class and significantly reduces energy losses and thermal output.
Advancing wearable technology
Developing compact, lightweight, high-performance Schottky rectifiers represents a significant step forward for consumer electronics. By delivering industry-leading current density, these tiny rectifiers enable the design of smaller, more efficient devices with extended battery life and improved performance. As wearable technology and compact electronics evolve, integrating such advanced components will be key to meeting the demands of the next generation of consumer devices.
