Overview: .. M I C R O T U N E RF SILICON AND SYSTEMS SOLUTIONS FOR BROADBAND MUNICATIONS, AUTOMOTIVE ELECTRONICS AND WIRELESS CONNECTIVITY The MT1550 is a low-cost programmable-gain power amplifier IC for use in CATV upstream PRODUCT BRIEF applications. The Microtune® MT1550 is a 3.3 volt part optimized for the DOCSIS 1.1 upstream The MT1550 is a 3.3V programmable standard. The MT1550 also includes gain upstream amplifier with integrated an on-chip input anti-aliasing filter, anti-aliasing filter. thereby reducing external system costs. The device’s specified frequency range is from 5MHz to 65MHz, and can output 67dBmV through a 1:1 impedance-ratio transformer. A 3wire digital serial bus controls the variable gain, with gain control available in 1dB steps and a nominal 59dB gain range. The MT1550 may be disabled via an external control pin. The transmitdisable mode not only minimizes MT1550 Upstream Amplifier output noise by shutting off the output stage, but also maintains its output impedance at nominal levels. Output transients are nominally less than 16mVp-p at 61dBmV output level during transmit enable/disable switching. Operating from a single +3.3V supply, the amplifier’s typical current draw at maximum gain, or minimum attenuation, is 259mA. Additional internal circuitry reduces the amplifier’s power consumption depending on gain setting. Transmit-disable mode power supply current is reduced to a nominal of 62mA. A shutdown mode further reduces current to a nominal of 70µA. The MT1550 is available in a 20pin MicroLeadFrame™ package with an exposed pad for the extended industrial temperature range of -40°C to +85°C.
