Analog Devices AD6140 Datasheet

a

Bandpass ⌺⌬ IF Subsystem

AD6140

FEATURES
IF Subsystem

Bandpass ⌺⌬ Modulator
Variable-Gain Preamplifier with 13 dB of AGC Range
Mixer
AGC Detector
Op Amp for LNA Biasing
ECL-to-CMOS Level Translator

Ultralow Power Design

2.7 V Operating Voltage

4.8 mA Current Consumption
Power-Down Control

Small 20-Lead SSOP Package

APPLICATIONS
FLEX™, ReFLEX™ Receivers
Multimode Receivers

FUNCTIONAL BLOCK DIAGRAM

LO_IN+ LO_IN–

PREAMPLIFIER

IF_INPUT

LNA_SENSE

LNA_FORCE

AGC_CAPACITOR

0.1mF

AGC_TC_SELECT

LNA BIAS

AMPLIFIER

MIXER

AGC

DETECTOR

CIRCUIT

MIXER POST

AMPLIFIER

BIAS SYSTEM

GENERAL DESCRIPTION

The AD6140 is a bandpass Σ∆ ADC IF IC for receivers requiring

a high dynamic range and multiple filter bandwidths. With an
external decimation filter, it creates a multibit analog-to-digital
converter. The AD6140 consists of a variable gain, low noise

preamplifier, mixer, AGC detector, bandpass Σ∆ modulator, an

ECL-to-CMOS level translator for the system clock, and an
auxiliary amplifier for use in biasing a discrete LNA. It is de­signed to operate with Motorola’s ReFLEX chipset solution.
Contact Motorola directly for more information about the
ReFLEX chipset solution. With data and clock outputs at CMOS
logic levels, it interfaces to an external decimation filter. It comes in

a 20-lead plastic SSOP and operates over the –40°C to +85°C

industrial temperature range at 2.7 V.

AD6140

D

MODULATOR

ECL-TO-CMOS

LEVEL-SHIFTER

D_DATA_OUT
D_CLOCK_OUT

BUFFER_VDD
CLK_IN+
CLK_IN–
BUFFER_GND

VOLTAGE_REFERENCE_IN

AVDD AGND DGND DVDD POWER_DOWN

FLEX and ReFLEX are trademarks of Motorola, Inc.

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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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

R

INT

BIAS_RESISTOR

39kV

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 1998

AD6140–SPECIFICATIONS

Specification Conditions Min Typ Max Units

OVERALL VOLTAGE_REFERENCE_IN = 1 V ± 5% dc,

IF = 49.6 MHz
LO = 49.792 MHz or 49.408 MHz, 200 mV p-p

Differential Input

Clock = 6.144 MHz, 800 mV p-p Differential ECL

Input, Clock Asymmetry = 50 ± 2.5%

Input Third Order Intercept Point At Max Gain –27 –19 dBm
Noise Figure At Max Gain, External Termination 10.5 dB

Input Resistance At IF_INPUT (Pin 19) 2.5 kΩ

Input Capacitance At IF_INPUT (Pin 19) 12 pF
Dynamic Range 6.25 kHz Bandwidth Centered at 192 kHz 76 83 dB
Maximum Gain 29.5 dB
Minimum Gain 16 dB

AGC DETECTOR

AGC Threshold –24 dBm

Capacitor Charging Current AGC_TC_SELECT Input = Logic LOW (FAST AGC) 2.8 µA

AGC_TC_SELECT Input = Logic HIGH (SLOW AGC) 50 nA

ECL-TO-CMOS LEVEL VDD (to VDD – 0.8 V) Differential Levels

TRANSLATOR

Clock Output Drive 5 pF Load 2.6 V p-p

Clock Asymmetry 5 pF Load ±2.5 %

LNA BIAS AMPLIFIER VOLTAGE

LNA_FORCE 2.9 V LNA_SENSE, Minimum Gain 1.7 V
LNA_SENSE Input Voltage Range VDD VDD – 0.3 V

POWER-DOWN INTERFACE

Logic Threshold 0.7 V

Turn-On Response Time To Valid Data Output 100 µs
Turn-Off Response Time To Typical Power-Down Supply Current 100 µs

POWER SUPPLY

Supply Voltage 2.5 2.9 V
Supply Current Power-Down Input: Logic LOW = ON, IF_Input = 0 V 4.8 5.75 mA

Power-Down Current Power-Down Input: Logic HIGH = OFF 3 µA
Operating Temperature Range –40 +85 °C

Specifications subject to change without notice.

(TA = +25ⴗC, VCC = 2.7 V, VOLTAGE_REFERENCE_IN = 1 V, unless otherwise noted)

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AD6140

WARNING!

ESD SENSITIVE DEVICE

TOP VIEW

(Not to Scale)

20

19

18

17

16

15

14

13

12

11

1

2

3

4

5

6

7

8

9

10

AD6140

AGC TC SELECT

POWER

DOWN

BUFFER

VDD

LNA

SENSE

CLK

IN+

CLK

IN–

D CLOCK OUT

D DATA OUT

BUFFER

GND

DVDD

DGND

AGC

CAPACITOR

IF

INPUT
AGND
VOLTAGE

REFERENCE IN

LO

IN+

LO

IN–

BIAS

RESISTOR

LNA

FORCE

AVDD

ABSOLUTE MAXIMUM RATINGS

Supply Voltage to Ground . . . . . . . . . . . . . . . . . . . . . . +5.5 V

Internal Power Dissipation

2

. . . . . . . . . . . . . . . . . . . . 50 mW

1

PIN CONFIGURATION

Operating Temperature Range . . . . . . . . . . . –40°C to +85°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C

Lead Temperature, Soldering (60 sec) . . . . . . . . . . . . +300°C

NOTES

1

Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended rating conditions for extended periods may affect device
reliability.

2

Thermal Characteristics:

20-Lead SSOP: θJA = 126°C/W.

ORDERING GUIDE

Temperature Package Package

Model Range Description Option

AD6140ARS –40°C to +85°C Shrink Small Outline Package RS-20
AD6140ARSRL –40°C to +85°C 20-Lead Plastic SSOP on Tape-and-Reel

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD6140 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.

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