Octal Amplifier Eyes Ultrasound And Industrial Scanning Apps

Targeting portable ultrasound and industrial scanning applications, the VCA8613 integrates eight low-noise preamplifiers, eight attenuators, and eight post-gain amplifiers. Despite this level of integration, the device draws only 600 mW (75 mW per channel) while operating on a 3V supply. Each channel contains a low-noise preamplifier (LNA), voltage-controlled attenuator (VCA), and a programmable gain amplifier (PGA). The differential outputs of the LNAs can be switched through the device's 8 x 10 cross-point switch, which is programmable through a serial port. The gain range of the PGA can be digitally configured separately and varied between 21 dB and 26 dB. The VCA has four programmable maximum attenuation settings: 29, 33, 36.5, and 40 dB. The PGA feeds into an integrated two-pole, low-pass filter, allowing direct connection to a differential input a/d converter. Other features include a continuous wave processor, which is said to reduce the number of external components required to support CW Doppler mode. Available in a TQFP-64, price is $25.40 each/1,000. TEXAS INSTRUMENTS INC., Dallas, TX. (800) 477-8924.