How is the switching frequency selected for the LM5000?
The LM5000-3 operates at 300 kHz or 700 kHz selectable with an external pin, the LM5000-6 operates at 600 kHz or 1.25 MHz. High switching frequencies are generally needed in xDSL boost applications, and permit the use of smaller external components. In flyback and forward applications, lower switching frequencies at 300 kHz are generally preferred, and enable the reduction of core losses of the magnetics.
