How do I design an EMC compliant reset circuit that does not generate excessive broadband emissions?

Designing an EMC-compliant reset circuit that does not generate excessive broadband emissions requires ensuring that the reset signal's fast edges do not radiate through the PCB traces, power planes, or connected cables. Reset circuits are common EMI offenders because: they switch between power rail and ground with very fast edges (< 1-5 ns for CMOS logic), the reset trace typically runs across the entire board to reach every IC (creating a long antenna), and the reset signal may only assert periodically (creating a broadband impulse-like emission spectrum that covers 30 MHz to several GHz). Design techniques include: slowing the reset edge rate (add a series resistor of 50-200 ohms at the reset driver output to create an RC filter with the trace and load capacitance; this increases the rise/fall time to 10-50 ns, reducing the spectral content above 30-100 MHz while still meeting the IC's reset timing specification), using reset ICs with controlled slew rate (Maxim, TI, and Microchip offer supervisor/reset ICs with intentionally slow output edges of 10-100 us, designed for EMC compliance), filtering the reset line (add a ferrite bead in series with the reset trace, combined with a 100-1000 pF capacitor to ground near each IC to form a low-pass filter; cutoff frequency 10-50 MHz), routing the reset trace carefully (keep the trace short, route it adjacent to a ground return, never route the reset trace near board edges or across cable connector pins), and providing a local decoupling capacitor at the reset driver output (0.1 uF + 1 nF to ground, placed within 3 mm of the driver output).