The AFE5832 is an integrated analog front end (AFE) optimized for medical ultrasound applications. The device is implemented as a multi-chip module (MCM) with three chips: two voltage-controlled amplifier (VCA) chips and an analog-to-digital converter (ADC) chip. Each VCA chip has 16 channels and the ADC chip converts all 32 channels.

Each channel in the VCA chip is configured in one of two modes: time gain compensation (TGC) mode or continuous wave (CW) mode. In TGC mode, each channel consists of an input attenuator (ATTEN), a low-noise amplifier (LNA) with variable gain, and a third-order low-pass filter (LPF). The attenuator supports an attenuation range of 8 dB to 0 dB, and the LNA supports a gain range of 20 dB to 51 dB. The LPF cutoff frequency is configurable to 5 MHz, 7.5 MHz, 10 MHz, or 12.5 MHz to support ultrasound applications at different frequencies. In CW mode, each channel contains an LNA with a fixed gain of 18 dB, and a low-power passive mixer with 16 selectable phase delays. Different phase delays can be applied to each analog input signal to perform on-chip beamforming operations. Harmonic filters in the CW mixer suppress the third and fifth harmonics to enhance the sensitivity of CW Doppler measurements.

The ADC chip has 16 physical ADCs. Each ADC converts two sets of outputs—one from each VCA chip. The ADC is configured to operate at 12-bit or 10-bit resolution. ADC resolution can be traded off against conversion rate, and operates at maximum speeds of 80 MSPS and 100 MSPS at 12-bit and 10-bit resolutions, respectively. The ADC is designed to adjust its power based on the sample rate. The ADC’s output interface is via low-voltage differential signaling (LVDS) outputs, allowing easy interface to low-cost field-programmable gate arrays (FPGAs).

The AFE5832 also allows selection of various power and noise combinations to optimize system performance. Therefore, this device is a suitable ultrasonic AFE solution for systems with stringent battery life requirements.

Application areas
medical ultrasound imaging
Non-destructive testing equipment
Sonar imaging equipment
Multi-channel high-speed data acquisition