The AFE5818 is a highly-integrated, analog front-end (AFE) solution specifically designed for ultrasound systems where high performance and small size are required. The device integrates a complete time-gain-control (TGC) imaging path and a continuous wave Doppler (CWD) path. The device also allows various power and noise combinations to be selected to optimize system performance. Therefore, the AFE5818 is a suitable ultrasound AFE solution for high-end and portable systems
The AFE5818 has a total of 16 channels, with each channel consisting of a voltage-controlled amplifier (VCA), a simultaneous sampling 14-bit and 12-bit analog-to-digital converter (ADC), and a continuous wave (CW) mixer. The VCA includes a low-noise amplifier (LNA), a voltage-controlled attenuator (VCAT), a programmable gain amplifier (PGA), and a low-pass filter (LPF). LNA gain is programmable and supports 250-mVPP to 1-VPP input signals and programmable active termination. The ultra-low noise VCAT provides an attenuation control range of 40 dB and improves overall low-gain SNR, which benefits harmonic and near-field imaging. The PGA provides gain options of 24 dB and 30 dB. In front of the ADC, an LPF can be configured at 10 MHz, 15 MHz, 20 MHz, 30 MHz, 35 MHz, or 50 MHz to support ultrasound applications with different frequencies.
The AFE5818 also integrates a low-power passive mixer and a low-noise summing amplifier to create an on-chip CWD beamformer. 16 selectable phase delays can be applied to each analog input signal. Furthermore, a unique third- and fifth-order harmonic suppression filter is implemented to enhance CW sensitivity
The high-performance, 14-bit ADC achieves 75-dBFS SNR. This ADC ensures excellent SNR at low-chain gain. The device can operate at maximum speeds of 65 MSPS and 80 MSPS, providing a 14-bit and a 12-bit output, respectively.
The ADC low-voltage differential signaling (LVDS) outputs enable a flexible system integration that is desirable for miniaturized systems.
The AFE5818 also allows various power and noise combinations to be selected to optimize system performance. Therefore, the AFE5818 is a suitable ultrasound AFE solution for both high-end and portable systems.
The AFE5818 is available in a 15-mm × 15-mm NFBGA-289 package (ZBV package, S-PBGA-N289) and are specified for operation from –40°C to 85°C. The devices are also pin-to-pin compatible with the AFE5816 device family.