DESIGN
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conditions
• Low ripple and noise: the HRF15
Figure 2. XP Power’s HRF Series meets the stringent power supply requirements of critical, noise-sensitive applications such as precision imaging and inspection systems
offers output ripple as low as 0.001%. This ultra-low ripple is critical for maintaining a stable electron beam and producing high-resolution, sharp images free from distortion caused by voltage fluctuations • High stability over time: the series boasts stability as low as 10 ppm/hour and 25 ppm/eight hours after a one-hour warm-up period. This high stability is a significant differentiator compared to alternatives in the market, which may have stability figures like 70 ppm/ hour or 200 ppm/eight hours. For a typical 15kV output voltage, a 10ppm stability corresponds to a voltage drift of only 0.15V (15,000V * 10/1,000,000), which is considered a very low drift. This stability ensures consistent beam energy and repeatable measurements over extended operational periods, which is crucial for eight-hour shifts in production environments • Low temperature coefficient: with a temperature coefficient of 25 ppm/°C, the HRF15 minimises voltage variation due to changes in ambient temperature. This ensures consistent performance
• Low partial discharge: partial discharges are electrical discharges that do not completely bridge the insulation between conductors. In high voltage systems powering SEMs, these discharges can introduce spikes or noise that affect image quality and the overall reliability of the power supply and system. Minimising partial discharges is a critical requirement In semiconductor inspection, particularly for sub-5nm nodes, even nanometre-scale deviations caused by power supply instability can lead to costly misinterpre- tation of defect size or location, impacting yield. The demanding size constraints in modern inspection systems also require compact power supply form factors that do not sacrifice performance. Addressing the challenges Precision high voltage DC/DC converters, such as those in the HRF series from XP Power, are designed specifically to meet the stringent power supply requirements of critical, noise-sensitive applications. The platform offers several key features that directly address the pain points faced by engineers:
across the specified operating temperature range of 0 to +50°C
42 ELECTRONICSPECIFIER.COM
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