Radar Receive Path AFE: 4-Channel Mux

with LNA, PGA, AAF, and ADC

Data Sheet

AD8284

Rev. D

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FEATURES

4-channel mux to LNA, PGA, AAF

1 direct-to-ADC channel

Programmable gain amplifier (PGA)

Includes low noise preamplifier (LNA)

SPI-programmable gain = 17 dB to 35 dB in 6 dB steps

Antialiasing filter (AAF)

Programmable third-order low-pass elliptic filter (LPF) from

9 MHz to 15 MHz

Analog-to-digital converter (ADC)

12 bits of accuracy of up to 60 MSPS

SNR = 67 dB

SFDR = 68 dBc

Low power, 345 mW at 12 bits per 60 MSPS

Low noise, 3.5 nV/√Hz maximum of input referred

voltage noise

Power-down mode

64-lead, 10 mm × 10 mm TQFP 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

Figure 1.

GENERAL DESCRIPTION

The AD8284 is an integrated analog front end designed for low

cost, compact size, flexibility, and ease of use. It contains a

4-channel differential multiplexer (mux), a 1-channel low noise

preamplifier (LNA) with a programmable gain amplifier (PGA)

and an antialiasing filter (AAF), as well as one direct-to-ADC

channel, all integrated with a single, 12-bit analog-to-digital

converter (ADC). The AD8284 also incorporates a saturation

detection circuit for high frequency overvoltage conditions that

would otherwise be filtered by the AAF.

The analog channel features a gain range of 17 dB to 35 dB in

6 dB increments, and an ADC with a conversion rate of up to

60 MSPS. The combined input referred voltage noise 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 CMOS process, the AD8284 is available

in a 10 mm × 10 mm, RoHS compliant, 64-lead TQFP. It is speci-

fied over the automotive temperature range of −40°C to +105°C.

Table 1. Related Devices

Part No.

Description

AD8285

4-Channel LNA/PGA/AAF, pseudosimultaneous

channel sampling with ADC

AD8283

6-Channel LNA/PGA/AAF, pseudosimultaneous

channel sampling with ADC

ADA8282

4-Channel LNA/PGA

INA+

INA–

INB+

INC+

INC–

INB–

IND+

IND–

INADC+

INADC–

SPI

AD8284

SATURATION

DETECTION

REFERENCE

D0

TO

D11

12-BIT

ADC

MUX

LNA

MUX

PGA

AAF