How is the FNX14701 able to operate at significantly lower power than existing solutions?
The FNX14701 consumes about 240mW at full duty cycle and less than 50mW with a duty cycle of about 19% when receiving a single Band III, 128kbps audio signal. This ultra low power consumption is possible due to two main reasons: Firstly, as a zero-IF architecture is employed, the down-conversion occurs in only one stage as compared to several stages in superheterodyne solutions. Less stages means less power. Also, the signal remains on-chip until the IF output at 2.048MHz (or quadrature I-Q outputs at 0Hz). Hence, less power is required in driving power-hungry output buffers as compared to superheterodyne solutions which require external high Q filtering at a higher IF. Secondly, the FNX14701 supports power-cycling. This technique exploits the fact that the data payload of the DAB stream is time-multiplexed. Several sub-channels are broadcasted simultaneously on a single multiplex, but typical usage would not require the decoding of all the sub-channels. Consequently, for the period wh
