AD9277八进制的低噪声放大器 /显卡/工具/14位模数转换器连续解调器

　　The AD9277 is designed for low cost， low power， small size， and ease of use. It contains eight channels of a variable gain amplifier （VGA） with a low noise preamplifier （LNA）; an antialiasing filter （AAF）; a 14-bit， 10 MSPS to 50 MSPS analog-todigital converter （ADC）; and an I/Q demodulator with programmable phase rotation. Each channel features a variable gain range of 42 dB， a fully differential signal path， an active input preamplifier termination， a maximum gain of up to 52 dB， and an ADC with a conversion rate of up to 50 MSPS. The channel is optimized for dynamic performance and low power in applications where a small package size is critical. The LNA has a single-ended-to-differential gain that is selectable through the SPI. The LNA input noise is typically 0.75 nV/√Hz at a gain of 21.3 dB， and the combined input-referred noise of the entire channel is 0.85 nV/√Hz at maximum gain. Assuming a 15 MHz noise bandwidth （NBW） and a 21.3 dB LNA gain， the input SNR is roughly 92 dB. In CW Doppler mode， each LNA output drives an I/Q demodulator. Each demodulator has independently programmable phase rotation through the SPI with 16 phase settings. The AD9277 requires a LVPECL-/CMOS-/LVDS-compatible sample rate clock for full performance operation. No external reference or driver components are required for many applications.