DOCSIS 3.0 Upstream Amplifier

The MAX3521 is an integrated CATV upstream amplifier IC designed to exceed the DOCSIS 3.0 requirements. It provides a maximum output power level 3dB higher than the DOCSIS 3.0 specification for all modulation standards and channel configurations. The amplifier covers an 5MHz to 85MHz input frequency range (275MHz, 3dB bandwidth). It is capable of transmitting four QPSK modulated carriers, each at +61dBmV, simultaneously within this range. The gain is controlled in 1dB steps over a 63dB range using an SPI 3-wire interface.

The device operates from a single +5V supply. Four power codes are provided to allow maximum supply current to be reduced as determined by distortion requirements. In addition, for each power code, supply current is automatically reduced as gain is reduced while maintaining distortion performance. The supply current drops to 5mA between bursts to minimize power dissipation in transmit-disable mode. Control signal logic levels are 3.3V CMOS.

The MAX3521 is the most recent addition to Maxim’s pin-compatible cable upstream amplifier family, which includes the MAX3518. The MAX3521 is available in a 20-pin TQFN package and operates over the extended industrial temperature range (-40°C to +85°C).

Applications

* DOCSIS 3.0 Plus Cable Modems and Gateways * Set-Top Boxes * VOIP Modems

* +5V Supply Voltage

* Ultra-Low 25mW Dissipation in Transmit-Disable Mode

* 63dB Gain-Control Range in 1dB Steps

* -65dBc Harmonic Distortion at 67dBmV Output

* Small 5mm x 5mm TQFN Package

* Low Burst On/Off Transient

* 275MHz, 3dB Bandwidth

* Multiple Power Modes for Optimal Battery Life