SI9161 Datasheet, PDF (12/12 Pages) Vishay Siliconix – Optimized-Efficiency Controller for RF Power Amplifier Boost Converter

Si9161
Vishay Siliconix
FIGURE 9. Higher resolution of noise spectrum
Conclusion
Switching at high, known frequencies results in a smaller
footprint while maintaining high efficiency. Efficiencies at high
switching frequencies can be improved by using Si6801
optimized low gate charge and low gate resistance MOSFET.
Even though the high frequency MOSFET has been designed
with minimum gate charge, it still presents significant power
loss during the light load conditions. In order to minimize this
switching loss, Si9161 is designed with a light load efficiency
improvement pin which decreases the switching frequency by
8.5 times (@ 1 MHz) and disables the synchronous
rectification. This feature improves the light load efficiency in
certain conditions as much as 50% compare to Si9160.
Additionally, under transmitting mode, Si9161 clock frequency
can be synchronized to higher external frequency which
eliminates or greatly reduces any radio interference concerns
and pushes harmonics out beyond signal processing
frequencies.
S-60752—Rev. B, 05-Apr-99
12
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