ADI AD9279 8路超声波系统资料下载

dgaitymq120379

ADI 公司的AD9279是8路LNA/VGA/AAF/ADC和CW I/Q解调器,包括了8路可变增益放大器(VGA)和低噪音前置放大器(LNA),抗混淆滤波器(AAF),模数转换器(ADC)以及带可变肠相位旋转的I/Q解调器,每路增益45dB,TGC模式和40MSPS时的每路功耗141mW,CW模式每路功耗60mW,主要用在医疗超声波和汽车雷达.本文介绍了AD9279主要特性,单路方框图, 超声波系统方框图以及AD9279各种输入电路, 单端1.8V/3.3V CMOS取样时钟电路图和CW模式 I/O输出接口连接典型电路图.

Octal LNA/VGA/AAF/ADC and CW I/Q Demodulator

The AD9279 is designed for low cost, low power, small size, and ease of use for medical ultrasound and automotive radar. It contains eight channels of a variable gain amplifier (VGA) with a low noise preamplifier (LNA), an antialiasing filter (AAF), an analog-to-digital converter (ADC), and an I/Q demodulator with programmable phase rotation.

Each channel features a variable gain range of 45 dB, a fully differential signal path, an active input preamplifier termination, and a maximum gain of up to 52 dB. The channel is optimized for high 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. Assuming a 15 MHz noise bandwidth (NBW) and a 21.3 dB LNA gain, the LNA input SNR is roughly 94 dB. In CW Doppler mode, each LNA output drives an I/Q demod-ulator that has independently programmable phase rotation with 16 phase settings.

Power-down of individual channels is supported to increase battery life for portable applications. Standby mode allows quick power-up for power cycling. In CW Doppler operation, the VGA, AAF, and ADC are powered down. The ADC contains several features designed to maximize flexibility and minimize system cost, such as a programmable clock, data alignment, and programmable digital test pattern generation. The digital test patterns include built-in fixed patterns, built-in pseudo random patterns, and custom user-defined test patterns entered via the serial port interface.