Overview

The LC72706E is a data demodulation IC for receiving FM multiplex broadcasts for mobile receivers in the DARC format. In conjunction with a bandpass filter IC (either the LV3400M or the LV3403M), the LC72706E can form a compact yet high-functionality FM multiplex reception system. This IC supports all the FM multiplex frame structures (methods A, B, and C) in the ITU-R recommendations.

Functions

• MSK delay detection circuit based on a 1T delay

• Error correction function based on a 2T delay (in the MSK detector stage)

• Digital PLL based clock regeneration circuit

• Shift-register type 1T and 2T delay circuits

• Block and frame synchronization detection circuit

• Serial control data transfer based support for the A, B, and C FM multiplex frame structures

• Function for setting the number of allowable BIC errors, the number of synchronization protection.

• Error correction using (272, 190) codes

• Layer 4 CRC code checking circuit

• On-chip frame memory and memory control circuit for vertical correction

• 7.2-MHz crystal oscillator circuit

Applications

• Receivers for DARC format mobile receiver FM multiplex broadcasts