AD8285 Datasheet, PDF (1/27 Pages) Analog Devices – Radar Receive Path AFE - 4-Channel LNA/PGA/AAF with ADC

Data Sheet
Radar Receive Path AFE: 4-Channel
LNA/PGA/AAF with ADC
AD8285
FEATURES
4-channel LNA, PGA, and AAF
1 direct to ADC channel
Programmable gain amplifier (PGA)
Includes low noise preamplifier (LNA)
Serial peripheral interface (SPI) programmable gain
16 dB to 34 dB in 6 dB steps
Antialiasing filter (AAF)
Programmable third order, low-pass elliptic filter (LPF)
from 1.0 MHz to 12.0 MHz
Analog-to-digital converter (ADC)
12 bits of accuracy up to 72 MSPS
Signal-to-noise ratio (SNR): 68.5 dB
Spurious-free dynamic range (SFDR): 68 dB at gain = 16 dB
Low power: 185 mW per channel at 12 bits and 72 MSPS
Low noise: 3.5 nV/√Hz maximum of input referred voltage noise
Power-down mode
72-lead, 10 mm × 10 mm LFCSP package
Specified from −40°C to +105°C
Qualified for automotive applications
APPLICATIONS
Automotive radar
Adaptive cruise control
Collision avoidance
Blind spot detection
Self parking
Electronic bumper
FUNCTIONAL BLOCK DIAGRAM
INA+
INA–
INB+
INB–
INC+
INC–
IND+
IND–
INADC+
INADC–
LNA PGA _AAF
LNA PGA _AAF
LNA PGA AAF
LNA PGA _AAF
SPI
REFERENCE
MUX
12-BIT
ADC
DRV
AD8285
DSYNC
D[0:11]
NOTES
1. AVDD18x = AVDD18, AVDD18ADC.
AVDD33x = AVDD33, AVDD33A, AVDD33B, AVDD33C, AVDD33D, AVDD33REF.
DVDD18x = DVDD18, DVDD18CLK. DVDD33x = DVDD33, DVDD33SPI, DVDD33CLK, DVDD33DRV.
Figure 1.
GENERAL DESCRIPTION
The AD8285 is designed for low cost, low power, compact size,
flexibility, and ease of use. It contains four channels of a low noise
preamplifier (LNA) with a programmable gain amplifier (PGA)
and an antialiasing filter (AAF) plus one direct to ADC channel, all
integrated with a single 12-bit analog-to-digital converter (ADC).
Each channel features a gain range of 16 dB to 34 dB in 6 dB
increments and an ADC with a conversion rate of up to 72 MSPS.
The combined input referred noise voltage of the entire channel
is 3.5 nV/√Hz at maximum gain. The channel is optimized for
dynamic performance and low power in applications where a
small package size is critical.
Fabricated in an advanced complementary metal oxide
semiconductor (CMOS) process, the AD8285 is available in a
10 mm × 10 mm, RoHS compliant, 72-lead LFCSP that is specified
over the automotive temperature range of −40°C to +105°C.
Table 1. Related Devices
Part No. Description
AD8283 6-channel LNA/PGA/AAF, pseudo simultaneous
channel sampling with ADC
AD8284 4-channel LNA/PGA/AAF, sequential channel
sampling with ADC
ADA8282 4-channel LNA/PGA
Rev. B
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