Low-Ripple Power Supply Design for Photolithography Light Sources

Photolithography light sources demand extremely stable power, as voltage ripple can induce fluctuations in light intensity and compromise pattern fidelity. Low-ripple power supply design is critical for maintaining uniform exposure and achieving high-resolution patterning.
Modern photolithography power systems employ a combination of multi-stage filtering and active regulation. High-frequency EMI filters at the input suppress line interference, while DC-DC conversion stages with LC or Pi-type filters reduce internal switching ripple. At the output, active compensation circuits dynamically counter residual noise using high-speed operational amplifiers.
Digital regulation further enhances performance. High-speed ADCs sample light source voltage and current, enabling feedback control via PID or adaptive algorithms to adjust voltage in real time. The system maintains low ripple even during dynamic changes in light intensity, preserving optical stability. Such designs can achieve output ripple at the microvolt level, ensuring consistent illumination and enabling high-resolution lithographic processes.