Octal LNA/VGA/AAF/ADC
and Crosspoint Switch
AD9273
Rev. B
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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
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Fax: 781.461.3113
©2009 Analog Devices, Inc. All rights reserved.
FEATURES
8 channels of LNA, VGA, AAF, and ADC
Low noise preamplifier (LNA)
Input-referred noise voltage = 1.26 nV/√Hz
(gain = 21.3 dB) @ 5 MHz typical
SPI-programmable gain = 15.6 dB/17.9 dB/21.3 dB
Single-ended input; V
IN
maximum = 733 mV p-p/
550 mV p-p/367 mV p-p
Dual-mode active input impedance matching
Bandwidth (BW) > 100 MHz
Full-scale (FS) output = 4.4 V p-p differential
Variable gain amplifier (VGA)
Attenuator range = −42 dB to 0 dB
SPI-programmable PGA gain = 21 dB/24 dB/27 dB/30 dB
Linear-in-dB gain control
Antialiasing filter (AAF)
Programmable 2nd-order low-pass filter (LPF) from
8 MHz to 18 MHz
Programmable high-pass filter (HPF)
Analog-to-digital converter (ADC)
12 bits at 10 MSPS to 50 MSPS
SNR = 70 dB
SFDR = 75 dB
Serial LVDS (ANSI-644, IEEE 1596.3 reduced range link)
Data and frame clock outputs
Includes an 8 × 8 differential crosspoint switch to support
continuous wave (CW) Doppler
Low power, 109 mW per channel at 12 bits/40 MSPS (TGC)
70 mW per channel in CW Doppler
Flexible power-down modes
Overload recovery in <10 ns
Fast recovery from low power standby mode, <2 μs
100-lead TQFP and 144-ball BGA
APPLICATIONS
Medical imaging/ultrasound
Automotive radar
GENERAL DESCRIPTION
The AD9273 is designed for low cost, low power, small size, and
ease of use. It contains eight channels of a low noise preamplifier
(LNA) with a variable gain amplifier (VGA); an antialiasing
filter (AAF); and a 12-bit, 10 MSPS to 50 MSPS analog-to-
digital converter (ADC).
Each channel features a variable gain range of 42 dB, a fully
differential signal path, an active input preamplifier termination, a
maximum gain of up to 52 dB, and an ADC with a conversion
rate of up to 50 MSPS. The channel is optimized for dynamic
performance and low power in applications where a small
package size is critical.
FUNCTIONAL BLOCK DIAGRAM
SER
IA
L
PO
R
T
INT
E
RF
ACE
REFERENCE
FCO+
FCO–
DCO+
DCO–
LNA
LO-H
LOSW-H
LI-H
LG-H
12-BIT
ADC
SERIAL
LVDS
DOUTH+
DOUTH–
LNA
LO-G
LOSW-G
LI-G
LG-G
12-BIT
ADC
SERIAL
LVDS
DOUTG+
DOUTG–
LNA
LO-F
LOSW-F
LI-F
LG-F
12-BIT
ADC
SERIAL
LVDS
DOUTF+
DOUTF–
LNA
LO-E
LOSW-E
LI-E
LG-E
12-BIT
ADC
SERIAL
LVDS
DOUTE+
DOUTE–
LNA
LO-D
LOSW-D
LI-D
LG-D
12-BIT
ADC
SERIAL
LVDS
DOUTD+
DOUTD–
LNA
LO-C
LOSW-C
LI-C
LG-C
12-BIT
ADC
SERIAL
LVDS
DOUTC+
DOUTC–
LNA
LO-B
LOSW-B
LI-B
LG-B
12-BIT
ADC
SERIAL
LVDS
DOUTB+
DOUTB–
LNA
LO-A
LOSW-A
LI-A
LG-A
12-BIT
ADC
SERIAL
LVDS
DOUTA+
DOUTA–
AV
DD1
AV
DD2
ST
B
Y
DRV
DD
PD
W
N
CL
K–
CL
K+
SD
IO
SC
L
K
CS
B
RBI
AS
VR
EF
GA
IN
+
GA
IN
–
CW
D[
7
:0]
+
AND
C
W
D[
7:
0]
–
SWITCH
ARRAY
DAT
A
RAT
E
MU
L
T
IP
L
IER
AAF
AAF
AAF
AAF
AAF
AAF
AAF
AAF
AD9273
VGA
VGA
VGA
VGA
VGA
VGA
VGA
VGA
070
30-
001
Figure 1.
The LNA has a single-ended-to-differential gain that is selectable
through the SPI. The LNA input-referred noise voltage is typically
1.26 nV/√Hz at a gain of 21.3 dB, and the combined input-referred
noise voltage of the entire channel is 1.42 nV/√Hz at typical
gain. Assuming a 15 MHz noise bandwidth (NBW) and a 21.3 dB
LNA gain, the input SNR is about 91 dB. In CW Doppler mode,
the LNA output drives a transconductance amp that is switched
through an 8 × 8 differential crosspoint switch. The switch is
programmable through the SPI.
Summary of Contents for AD9273
Page 47: ...AD9273 Rev B Page 46 of 48 NOTES...
