Green Adaptive Cable Equalizer

Overview:

The GS2994 is a high-speed BiCMOS integrated circuit designed to equalize and restore signals received over 75Ω coaxial cable.

The device is designed to support SMPTE 424M, SMPTE292M and SMPTE 259M, and is optimized for performance at 270Mb/s, 1.485Gb/s and 2.97Gb/s.

The GS2994 features DC restoration to compensate for the DC content of SMPTE pathological test patterns.

The Carrier Detect output pin (CD) indicates whether a valid input signal has been detected. It can be connected directly to the SLEEP pin to enable automatic power-down upon loss of carrier. In the manual sleep mode, a voltage programmable threshold, which can be changed via the SQ_ADJ pin, forces CD high when the input signal amplitude falls below the threshold. This allows the GS2994 to distinguish between low-amplitude SDI signals and noise at the input of the device.

The equalizing and DC restore stages are disengaged when the BYPASS pin is HIGH. No equalization occurs in Bypass mode.

The GS2994 includes a gain selection pin (GAIN_SEL) which, when tied HIGH, compensates for 6dB flat attenuation.

The differential outputs can be DC-coupled to Gennum 3.3V cable drivers and reclockers and to industry-standard 1.2V, 2.5V and 3.3V CML logic. In general, DC-coupling to any termination voltage between 1.2V and 3.3V is supported.

The GS2994 also includes programmable de-emphasis with three operating levels in order to support long PCB traces. The GS2994 is footprint and drop-in compatible with existing GS2974 and GS2984 designs.

The device is available in a 16-pin, 4mm x 4mm QFN package. Power consumption of the GS2994 is typically 166mW when DC-coupled at 1.2V.

The GS2994 is Pb-free, and the encapsulation compound does not contain halogenated flame retardant.