Ultrasound firms testing Burr-Brown chip

Integrated circuit developer Burr-Brown hopes to offer ultrasound manufacturers more choice in products that block out extraneous return noise and amplify signals clearly.

Burr-Brown’s VCA2612 voltage-controlled attenuator follows the Tucson-based company’s 8-bit analog-to-digital converters, the ADS830 and ADS831 (SCAN 6/24/98) to market.

Ultrasound companies have purchased about 1000 experimental quantities of VCA2612 amplifiers to see how they perform, said Mike Koen, Burr-Brown’s manager of high-speed product development.

“The chip is being evaluated worldwide,” he said.

In an ultrasound system, signals reflected from tissue close to the surface are received quickly and require no amplification, while signals received from reflections off the deepest tissue require amplification. These signals are at such low power levels that noise in the receiving channel gets in the way of the ultrasound system imaging well. The VCA2612 is a low-noise, variable-gain amplifier with the ability to change gain so return echoes are captured without distortion, Koen said.

The VCA2612 also contains ADC capabilities. The output of the VCA2612 chip goes to another chip and converts the energy to digital form so an image is created on a computer screen. Burr-Brown started developing the VCA2612 after asking purchasers of the ADS830 and ADS831 if there were any other features of circuit chips that could improve their systems, Koen said.

“We have to give them a reason to switch over to our chip rather than (stay with) the original chip that is already on the market,” he added.

The amplifying abilities of the VCA2612 can be adjusted according to the part of the body the sonographer wants to image.