AZG489

The AZG489 is a multiple output cable driver specifically designed to drive coaxial video cables. The device is especially useful in Digital Video Broadcasting applications. Each output has its own output stage and thus each is isolated from the other outputs.

The AZG489 has a voltage gain of approximately 40 and produces an output swing of 1.6 volts, twice as large as a standard PECL output. When driving a coaxial cable, proper termination is required at both ends of the cable to minimize reflections. The 1.6V output signal allows for termination at both ends of the cable, while providing an 800mV signal at the receiving end of the cable.

The AZG489 accepts a standard differential PECL input and can be powered with a 5.0V supply. Under open input conditions internal input clamps will force all outputs HIGH.

Additional power supply filtering is required because of the large amount of in-phase output current. A capacitor (0.1F minimum) must bypass VCC to VEE in close proximity to the AZG489. A ferrite bead (1K @ 100 MHz) must be placed in series to the VEE pin. Additional capacitance may be required based on board layout. See Figure 1 for further information.

NOTE: The specifications in the PECL table are valid when thermal equilibrium is established. The maximum junction temperature is 125°C. Thermal management may be required in some applications to ensure the junction temperature does not exceed that value.