Each of the two ports is internally configured for a fixed 11.6V/V gain using a specific external build out resistor and a cross-coupled feedback, providing active output impedance with reduced losses. A three-pin serial interface allows each port to be separately tuned to the minimum required quiescent current for the intended signal standard.
Two external supply voltage boost caps provide a brief peak in the total output stage voltage to supply the peak line voltages using a control signal from the AFE.
Features and Benefits
Nominal quiescent current to support full line power for ADSL2+ is only 8mA/port; VDSL2+ 8b is 10mA/port; and VDSL2+ 17a is only 12mA/port For the most demanding 8b profile, total quiescent power to deliver 19.5dBm to the line is reduced from >900mW/port to <620mW/port Signal peaks maintains a signal linearity comparable to much higher power +24V class AB solutions Provides < -60dBc MultiBand Power Ratio to the highest target line powers Pricing and Availability The ISL1561 is available now in compact 24-lead QFN packages, with prices starting at $2.57 each in 1,000-unit quantities.