Analog Devices Introduces Complete Analog Front End For Advanced Ultrasound Equipment

ADI pairs quad amplifiers and data converters to increase channel density and improve image quality, while reducing package size, power and cost.

Analog Devices Inc. is introducing a quad variable gain amplifier (VGA) and two quad analog-to-digital converters (ADCs) that dramatically improve image quality in advanced medical ultrasound equipment. Leveraging Analog Devices' system-level signal chain and medical applications expertise, the new components, while available separately, together provide a complete, optimized analog front end (AFE) that not only increases dynamic range and image resolution in ultrasound equipment, but reduces package size, per-channel power consumption and bill of materials costs. The quad VGA and 10- and 12-bit quad ADCs also feature serial, low-voltage differential signaling (LVDS) data outputs that simplify board layout and further enhance image quality by enabling more data conversion paths to be routed within a given printed circuit board area. Advanced ultrasound equipment must process signals with very high dynamic range to account for the variability in tissue and bone density, fluid viscosity, and the rate of fluid movement in the body. Furthermore, medical equipment designers need ever-higher channel densities, which require hundreds of data converters and amplifiers per system to enable the ultrasound AFE to render an accurate, high-quality image.

About the AD8334 Quad Variable Gain Amplifier
The AD8334 quad VGA sets a new standard of performance for high-end ultrasound equipment designers by achieving a 101-dB signal-to-noise ratio (SNR) at 5 MHz, which is twice the SNR of the nearest competing VGA. In addition to superior image quality, the AD8334 uses 20 percent less area per channel, reduces per-channel power consumption by 20 percent and cuts per-channel costs by 10 percent that of other devices. The AD8334 also features an input-noise voltage level of only 0.74 nV/rtHz, while overload protection shields the device from ultrasound near-field signals and a selectable output clamping feature allows the VGA to protect the ADCs from signal saturation.

About the AD9228 and AD9219 Quad ADCs
The 12-bit AD9228 and 10-bit AD9219 quad ADCs provide an ideal match for Analog Devices' new AD8334 VGA. The AD9219 and the AD9228 are available in both 40- and 65-MSPS (million samples per second) speed grades and achieve a 70-dB SNR and 82-dB SFDR (spurious free dynamic range). The new quad ADCs consume half the board space and achieve a more than 20 percent reduction in per-channel power consumption relative to other ADCs. The devices also feature a programmable clock and data alignment and allow for digital test pattern generation using a serial port interface (SPI) that improves the ability of designers to control and synchronize output data.

Pricing and Availability
The AD8334 quad VGA is sampling and available in a 64-lead LFCSP (lead-frame chip-scale package). The AD8334 is priced at $14.49 per unit, in 1,000-piece quantities. The AD9219 and AD9228 quad ADCs are sampling and available in a 48-lead LFCSP. The AD9219 is priced at $15.98 for the 40-MSPS speed grade and at $19.98 for the 65-MSPS version in 1,000-piece quantities. The AD9228 is priced at $23.50 for the 40-MSPS speed grade and at $32.50 for the 65-MSPS version in 1,000-piece quantities.