National Semiconductor CLC5506 Manuals

National Semiconductor CLC5506 Gain Trim Amplifier (GTA)

The CLC5506 is a low-noise programmable gain amplifier for use in cellular base stations, WLL, radar and RF/IF subsystems where gain-control is required to increase the dynamic range. The CLC5506 allows designers to compensate for manufacturing component tolerances and temperature variations in receiver front ends. Maximum amplifier gain is set at 26 dB . A three-line MICROWIRE serial interface allows 16 dB of attenuation from the max gain setting in precise 0.25 dB steps. The CLC5506 uses a differential input and output, allowing large output swings on a single 5V rail. The differential output is well suited for impedance matching networks driving SAW filters or directly driving differential input analog to digital converters (ADC). The differential output also makes it possible to drive transformers allowing designers the ability to match a wide variety of transmission lines. The output amplifier has excellent output drive with low distortion. Digital control of the CLC5506 is accomplished using MICROWIRE Interface. Data Out and a Load Enable are incorporated so that more than one CLC5506/channel may be programmed per system. The CLC5506 maintains a 600MHz performance bandwidth over its entire gain and attenuation range from +10dB to +26dB. Gain control is divided into 64 equal steps of 0.25dB and is dB-linear. Output drive and distortion performance are excellent; In a 50Ω system, the third-order output harmonic distortion is less than -80dBc.