The document addresses the issue of "noise" in switching regulators, clarifying that it is actually coherent, high-frequency residue related to the regulator's switching rather than random noise. It explains how this energy appears as radiated and conducted components that can corrupt adjacent circuitry.
The text introduces a practical approach using the LT1533 monolithic regulator designed for low-noise switching supplies. This device utilizes slew-controlled output stages to minimize harmonic content during switching transitions, thereby reducing wideband spikes while maintaining efficiency.
| Input Voltage Range | 2.7V to 30V |
|---|---|
| Undervoltage Lockout Threshold | 2.55V |
| Shutdown Current (ISHDN) | 20µA |
It is not random noise but coherent, high frequency residue directly related to the regulator's switching.
The VIN pin accepts an input supply in a 2.7V to 30V range.
The regulator achieves a performance of 100µV noise in a 100MHz bandwidth.
Each power transistor operates at a 1A capacity.