Abstract

Output ripple and noise of a power adapter are core metrics for precision electronics. The power adapter uses output LC filtering and low-ESR capacitors to keep ripple low. This power adapter covers ripple peak-to-peak, noise spectrum and transient response parameters, providing stable power for audio devices and precision sensors that demand clean supply.

1. Ripple Causes and Parameters

Output ripple of the power adapter mainly comes from switching ripple and high-frequency noise. Peak-to-peak ripple of the power adapter is controlled within 120mV at 20MHz bandwidth. Low-noise versions of the power adapter reduce ripple further to 60mV.

2. Output Filter Circuit Parameters

The output stage of the power adapter uses low-ESR electrolytic and high-frequency ceramic capacitors in parallel. Combined with ferrite beads, the power adapter forms an LC filter to remove high-frequency noise. Filter parameters of the power adapter must match dynamic load to avoid resonance.

3. Noise Spectrum Parameters

Switching noise of the power adapter concentrates from hundreds of kHz to tens of MHz. RC snubbers of the power adapter suppress switching spikes. Shielding and grounding of the power adapter reduce radiated noise.

4. Transient Response Parameters

During load step, output deviation of the power adapter stays within 5% with fast recovery. The transient of the power adapter shows no oscillation or overshoot. Stable dynamic response of the power adapter ensures reliable digital circuit operation.

5. Value of Low-Noise Design

Low ripple output of the power adapter avoids audio background noise and sensor drift. It provides clean power for high-accuracy equipment as an essential quality.

Conclusion

Low ripple and low noise design of the power adapter deliver clean, stable power for precision devices. For a low-noise power adapter, contact Simsukian for ripple waveforms and samples.

References

1. IEC 62368-1 Audio/video, information and communication technology equipment safety standard

2. DOE Level VI External Power Supply Standard (US)

3. IEC 63002 Interoperability specifications for external power supplies