描述 Description

The AFE5808 is a highly integrated analog front-end (AFE) solution specifically designed for ultrasound systems in which high performance and small size are required. The AFE5808 integrates a complete time-gain-control (TGC) imaging path and a continuous wave Doppler (CWD) path. It also enables users to select one of various power/noise combinations to optimize system performance. Therefore, the AFE5808 is a suitable ultrasound analog front end solution not only for high-end systems, but also for portable ones.The AFE5808 contains eight channels of voltage controlled amplifier (VCA), 14/12-bit Analog-to-Digital Converter (ADC), and CW mixer. The VCA includes Low noise Amplifier(LNA), Voltage controlled Attenuator(VCAT), Programmable Gain Amplifier(PGA), and Low-Pass Filter (LPF). The LNA gain is programmable to support 250 mVPP to 1 VPP input signals. Programmable active termination is also supported by the LNA. The ultra-low noise VCAT provides an attenuation control range of 40 dB and improves overall low gain SNR which benefits harmonic imaging and near field imaging. The PGA provides gain options of 24 dB and 30 dB. Before the ADC, a LPF can be configured as 10, 15, 20, or 30 MHz to support ultrasound applications with different frequencies. The high-performance 14 bit/65 MSPS ADC in the AFE5808 achieves 77 dBFS SNR. It ensures excellent SNR at low chain gain. The ADC’s LVDS outputs enable flexible system integration desired for miniaturized systems. The AFE5808 also integrates a low power passive mixer and a low noise summing amplifier to accomplish on-chip CWD beamformer. 16 selectable phase-delays can be applied to each analog input signal. Meanwhile a unique 3rd and 5th order harmonic suppression filter is implemented to enhance CW sensitivity. The AFE5808 is available in a 15-mm × 9-mm, 135-pin BGA package and it is specified for operation from 0°C to 85°C. It is also pin-to-pin compatible to the AFE5807, AFE5803, and AFE5808A.

特性 Features

? 8-Channel Complete Analog Front-End
? LNA, VCAT, PGA, LPF, ADC, and CW Mixer

? Programmable Gain Low-Noise Amplifier (LNA)
? 24/18/12 dB Gain
? 0.25/0.5/1 VPP Linear Input Range
? 0.63/0.7/0.9 nV/rtHz Input Referred Noise
? Programmable Active Termination

? 40 dB Low Noise Voltage Controlled Attenuator (VCAT)
? 24/30 dB Programmable Gain Amplifier (PGA)
? 3rd Order Linear Phase Low-Pass Filter (LPF)
? 10, 15, 20, 30 MHz

? 14-bit Analog to Digital Converter (ADC)
? 77 dBFS SNR at 65 MSPS
? LVDS Outputs

? Noise/Power Optimizations (Full Chain)
? 153 mW/CH at 0.75 nV/rtHz, 65 MSPS
? 98 mW/CH at 1.1 nV/rtHz, 40 MSPS
? 80 mW/CH at CW Mode

? Excellent Device-to-Device Gain Matching
? ±0.5 dB (typical) and ±0.9 dB (max)

? Low Harmonic Distortion
? Fast and Consistent Overload Recovery
? Passive Mixer for Continuous Wave Doppler (CWD)
? Low Close-in Phase Noise –156 dBc/Hz at 1 KHz off 2.5 MHz Carrier
? Phase Resolution of 1/16λ
? Support 16X, 8X, 4X and 1X CW Clocks
? 12-dB Suppression on 3rd and 5th Harmonics
? Flexible Input Clocks

? Small Package: 15 mm × 9 mm, 135-BGA
? APPLICATIONS
? Medical Ultrasound Imaging
? Nondestructive Evaluation Equipments