AD AD9670EBZ

Octal Ultrasound AFE
With Digital Demodulator
AD9670
Data Sheet
FEATURES
GENERAL DESCRIPTION
8 channels of LNA, VGA, AAF, ADC, and digital demodulator/
decimator
Low power: 150 mW per channel, TGC mode, 40 MSPS;
65 mW per channel, CW mode; <30 mW at power-up
10 mm × 10 mm, 144-ball CSP-BGA
TGC channel input-referred noise: 0.8 nV/√Hz, maximum gain
Flexible power-down modes
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)
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
decimation filter: 16 taps per decimation factor
The AD9670 is designed for low cost, low power, small size, and
ease of use for medical ultrasound. It contains eight channels of a
variable gain amplifier (VGA) with a low noise preamplifier (LNA),
a CW harmonic rejection I/Q demodulator with programmable
phase rotation, an antialiasing filter (AAF), an analog-to-digital
converter (ADC), and a digital demodulator and decimator for
data processing and bandwidth reduction.
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 independently programmable phase rotation with 16 phase settings.
Power-down of individual channels is supported to increase battery
life for portable applications. Standby mode allows quick powerup 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.
FUNCTIONAL BLOCK DIAGRAM
AVDD1 AVDD2
LO-A TO LO-H
DVDD
PDWN STBY
DRVDD
CWQ+
CWQ–
CWI+
CWI–
CWD AND I/Q
DEMODULATOR
LOSW-A TO LOSW-H
LI-A TO LI-H
LNA
LG-A TO LG-H
VGA
14-BIT
ADC
AAF
DEMODULATOR/
DECIMATOR
SERIALIZER
LVDS
DOUTA+ TO DOUTH+
DOUTA– TO DOUTH–
AD9670
8 CHANNELS
11041-001
FCO+
FCO–
DCO+
DCO–
CLK–
DATA
RATE
MULTIPLIER
CLK+
SDIO
CSB
SCLK
GPO[0:3]
SERIAL
PORT
INTERFACE
ADDR[0:4]
TX_TRIG–
NCO
TX_TRIG+
VREF
RBIAS
REFERENCE
GAIN+
GAIN–
MLO–
MLO+
RESET–
RESET+
LO
GENERATION
Figure 1.
For more information about the AD9670, contact Analog Devices, Inc., at [email protected]
Rev. Sp0
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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: 781.329.4700
©2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
Data Sheet
AD9670
©2013 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D11041F-0-1/13(Sp0)
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