AD9670EBZ Datasheet, PDF (1/2 Pages) Analog Devices – Octal Ultrasound AFE With Digital Demodulator

Data Sheet
Octal Ultrasound AFE
With Digital Demodulator
AD9670
FEATURES
GENERAL DESCRIPTION
8 channels of LNA, VGA, AAF, ADC, and digital demodulator/
The AD9670 is designed for low cost, low power, small size, and
decimator
ease of use for medical ultrasound. It contains eight channels of a
Low power: 150 mW per channel, TGC mode, 40 MSPS;
variable gain amplifier (VGA) with a low noise preamplifier (LNA),
65 mW per channel, CW mode; <30 mW at power-up
a CW harmonic rejection I/Q demodulator with programmable
10 mm × 10 mm, 144-ball CSP-BGA
phase rotation, an antialiasing filter (AAF), an analog-to-digital
TGC channel input-referred noise: 0.8 nV/√Hz, maximum gain
converter (ADC), and a digital demodulator and decimator for
Flexible power-down modes
data processing and bandwidth reduction.
Fast recovery from low power standby mode: <2 μs
Low noise preamplifier (LNA)
Input-referred noise: 0.78 nV/√Hz, gain = 21.6 dB
Programmable gain: 15.6 dB/17.9 dB/21.6 dB
0.1 dB compression: 1.00 V p-p/.75 V p-p/.45 V p-p
Flexible active input impedance matching
Variable gain amplifier (VGA)
Attenuator range: 45 dB, linear-in-dB gain control
Postamp gain (PGA): 21 dB/24 dB/27 dB/30 dB
Antialiasing filter (AAF)
Each channel features a maximum gain of up to 52 dB, a fully
differential signal path, and an active input preamplifier termination.
The channel is optimized for high dynamic performance and
low power in applications where a small package size is critical.
The LNA has a single-ended-to-differential gain that is selectable
through the SPI. Assuming a 15 MHz noise bandwidth (NBW) and
a 21.6 dB LNA gain, the LNA input SNR is 94 dB. In CW Doppler
mode, each LNA output drives an I/Q demodulator that has inde-
pendently programmable phase rotation with 16 phase settings.
Programmable second-order LPF from 8 MHz to 18 MHz or
13.5 MHz to 30 MHz and HPF
Analog-to-digital converter (ADC)
SNR: 75 dB, 14 bits up to 125 MSPS
Configurable serial LVDS
CW mode harmonic rejection I/Q demodulator
Individual programmable phase rotation
Dynamic range per channel: >160 dBc/√Hz
Close-in SNR: 156 dBc/√Hz, 1 kHz offset, −3 dBFS
Digital demodulator/decimator
I/Q demodulator with programmable oscillator FIR
Power-down of individual channels is supported to increase battery
life for portable applications. Standby mode allows quick power-
up for power cycling. In CW Doppler operation, the VGA, AAF,
and ADC are powered down. The ADC contains several features
designed to maximize flexibility and minimize system cost, such as
a programmable clock, data alignment, and programmable digital
test pattern generation. The digital test patterns include built-in
fixed patterns, built-in pseudorandom patterns, and custom
user-defined test patterns entered via the serial port interface.
This product is protected by a U.S. patent.
decimation filter: 16 taps per decimation factor
FUNCTIONAL BLOCK DIAGRAM
AVDD1 AVDD2 PDWN STBY
DVDD
DRVDD
LO-A TO LO-H
LOSW-A TO LOSW-H
LI-A TO LI-H
LG-A TO LG-H
LNA
CWD AND I/Q
DEMODULATOR
VGA
AAF
14-BIT
ADC
DEMODULATOR/
DECIMATOR
SERIALIZER LVDS
CWQ+
CWQ–
CWI+
CWI–
DOUTA+ TO DOUTH+
DOUTA– TO DOUTH–
LO
GENERATION
REFERENCE
8 CHANNELS
NCO
SERIAL
PORT
INTERFACE
AD9670
DATA
RATE
MULTIPLIER
FCO+
FCO–
DCO+
DCO–
Figure 1.
For more information about the AD9670, contact Analog Devices, Inc., at [e-mail].
Rev. Sp0
Document Feedback
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
©2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com