FX469

Rx, Tx and Carrier Detect paths each contain a bandpass filter to ensure the provision of optimum signal conditions both in the modem and for the Tx modulation circuitry.

The FX469 demonstrates a high sensitivity and good bit-error-rate under adverse signal conditions; the carrier detect time constant is set by an external capacitor, whose value should be arranged as required to further enhance this product's performance in high noise environments.

This low-power device requires few external components and is available in small outline plastic (S.O.I.C)and cerdip DIL packages.

The FX469 is a single-chip CMOS LSI circuit which operates as a full-duplex pin-selectable 1200, 2400 or 4800 baud FFSK Modem. The mark and space frequencies are 1200/1800, 1200/2400 and 2400/4800Hz respectively. Tone frequencies are phase continuous; transitions occur at the zero crossing point. Employing a common Xtal oscillator with a choice of two clock frequencies (1.008MHz or 4.032MHz) to provide baud-rate, transmit frequencies, and Rx and Tx synchronization, the transmitter and receiver operate entirely independently including individual section powersave functions.

The FX469 includes on chip circuitry for Carrier Detect and Rx Clock recovery, both of which are made