FX589

The FX589 is a single-chip modem employing Gaussian Minimum Shift Keying (GMSK) modulation.

Data rates of 4kb/s to 64kb/s and the choice of BT to 0.3 or 0.5 are pin-programmable functions to suit radio data channel bandwidth requirements.

The Rx and Tx digital data interfaces of FX589 are bit-serial and synchronised to Rx and Tx data clocks generated by the modem. Separate Rx and Tx Powersave/Enable inputs allow for full- or half-duplex operation.

Rx input levels of FX589 can be set by a suitable ac and dc level adjusting circuit built, with external components, around an on-chip Rx input amplifier.

Acquisition, lock and hold of Rx data signals is made easier and faster by the use of Rx Control Inputs to clamp, detect and/or hold input data levels and can be set by the system µProcessor as required.

Indication is available, from the Rx S/N output, as to the quality of the received signal.

The FX589 design features a low-current analogue/digital ASIC process offering significantly lower current consumption than DSP technology. For data rates up to 32kb/s the FX589 draws typically 1.5mA at 3.0 volts VDD and
for data rates up to 64kb/s at 5.0 volts, typically 4.0mA.

This low-power CMOS microcircuit of FX589 is available in both 24-pin plastic DIL and Small Outline (SOIC and SSOP) packages.