Analog Devices AD8390 Service Manual

Low Power, High Output Current

FEATURES

Voltage feedback amplifier

Ideal for ADSL and ADSL2+ central office (CO) and

customer premises equipment (CPE) applications

Enables high current differential applications

Low power operation

Single- or dual-power supply operation from 10 V (±5 V)

up to 24 V (±12 V)

4 mA total quiescent supply current for full power ADSL

and ADSL2+ CO applications

Adjustable supply current to minimize power

consumption
High output voltage and current drive
400 mA peak output drive current

44.2 V p-p differential output voltage
Low distortion
–82 dBc @ 1 MHz second harmonic
–91 dBc @ 1 MHz third harmonic
High speed: 300 V/µs differential slew rate

APPLICATIONS

ADSL/ADSL2+ CO and CPE line drivers
xDSL line driver
High current differential amplifiers

GENERAL DESCRIPTION

The AD8390 is a high output current, low power consumption
differential amplifier. It is particularly well suited for the central
office (CO) driver interface in digital subscriber line systems
such as ADSL and ADSL2+. While in full bias operation, the
driver is capable of providing 24.4 dBm output power into low
resistance loads. This is enough to power a 20.4 dBm line while
compensating for losses due to hybrid insertion, transformer
insertion, and back termination resistors.

The AD8390 fully differential amplifier is available in a ther­mally enhanced lead frame chip scale package (LFCSP-16) and
a 16-lead QSOP/EP. Significant control and flexibility in bias
current have been designed into the AD8390. The four power
modes are controlled by two digital bits,
provide three levels of driver bias and one powered-down state.
In addition, the I

pin can be used for fine quiescent current

ADJ

trimming to tailor the performance of
the AD8390.

PWDN (1,0) which

Differential Amplifier

AD8390

PIN CONFIGURATIONS

V

NC NCNC

OCM

1

+IN

PWDN1

PWDN0

4

–IN

DGND

NC NC

NC = NO CONNECT

Figure 1. 4 mm × 4 mm 16-Lead LFCSP

V

OCM

NC

+IN

PWDN1

PWDN0

–IN

NC

DGND

NC = NO CONNECT

Figure 2. 16-Lead QSOP/EP

The low power consumption, high output current, high output
voltage swing, and robust thermal packaging enable the AD8390
to be used as the central office line driver in ADSL, ADSL2+,
and proprietary xDSL systems, as well as in other high current
applications requiring a differential amplifier.

I

ADJ

1316

12

–OUT

V

EE

V

CC

+OUT

9

85

03600-0-001

161

NC

–OUT

NC

V

EE

V

CC

NC

+OUT

98

I

ADJ

03600-0-002

Rev. C

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 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: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

AD8390

TABLE OF CONTENTS

Specifications..................................................................................... 3

Setting the Output Common-Mode Voltage .......................... 10

Absolute Maximum Ratings............................................................ 5

Typical Thermal Properties............................................................. 5

ESD Caution.................................................................................. 5

Typical Performance Characteristics............................................. 6

Theory of Operation ........................................................................ 9

Applications....................................................................................... 9

Circuit Definitions ....................................................................... 9

Analyzing a Basic Application Circuit....................................... 9

Setting the Closed-Loop Gain .................................................... 9

Calculating Input Impedance ..................................................... 9

REVISION HISTORY

9/04–Data Sheet Changed from Rev. B to Rev. C

Change to Ordering Guide............................................................ 16

2/04–Data Sheet Changed from Rev. A to Rev. B.

Power-Down Features and the I

PWDN Pins............................................................................. 10

ADSL and ADSL2+ Applications......................................... 10

ADSL and ADSL2+ Applications Circuit............................ 10

Multitone Power Ratio (MTPR) ............................................... 11

Layout, Grounding, and Bypassing .......................................... 12

Power Dissipation and Thermal Management....................... 12

Outline Dimensions....................................................................... 13

Ordering Guide .......................................................................... 13

Pin ................................... 10

ADJ

Changed pub code.......................................................................... 16

1/04–Data sheet changed from Rev. Sp0f to Rev. A.

Added detailed description of product............................ Universal

Updated Outline Dimensions....................................................... 13

Rev. C | Page 2 of 16

AD8390

SPECIFICATIONS

VS = ±12 V or +24 V, RL = 100 Ω, G = 10, PWDN = (1,1), I

= NC, V

ADJ

= float, TA = 25°C, unless otherwise noted.

OCM

Table 1.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

–3 dB Small Signal Bandwidth V
Large Signal Bandwidth V
Peaking V
Slew Rate V

= 0.2 V p-p, RF = 10 kΩ 40 60 MHz

OUT

= 4 V p-p 25 40 MHz

OUT

= 0.2 V p-p 0.1 dB

OUT

= 4 V p-p 300 V/µs

OUT

NOISE/DISTORTION PERFORMANCE

Second Harmonic Distortion
Third Harmonic Distortion
Multitone Power Ratio (26 kHz to 1.1 MHz) Z = 100 Ω, P = 19.8 dBm,

= 1 MHz, V

f

C

= 1 MHz, V

f

C

LINE LINE

= 2 V p-p

OUT

= 2 V p-p

OUT

–82 dBc
–91 dBc
–70 dBc

crest factor (CF) = 5.4

Multitone Power Ratio (26 kHz to 2.2 MHz) Z = 100 Ω, P = 19.8 dBm,

LINE LINE

–65 dBc

crest factor (CF) = 5.4
Voltage Noise (RTI) f = 10 kHz 8 nV/√Hz
Input Current Noise f = 10 kHz 1 pA/√Hz

INPUT CHARACTERISTICS

RTI Offset Voltage (V
RTI Offset Voltage (V

) V

OS,DM(RTI)

) V

OS,DM(RTI)

– V

, V

+IN

– V

+IN

= midsupply –3.0 ±1.0 +3.0 mV

–IN

OCM

, V

= float –3.0 ±1.0 +3.0 mV

–IN

OCM

±Input Bias Current –4.0 –7.0 µA
Input Offset Current –0.35 ±0.05 +0.35 µA
Input Resistance 400 kΩ
Input Capacitance 2 pF
Common-Mode Rejection Ratio (∆V

OS,DM(RTI)

)/(∆V

) 58 64 dB

IN,CM

OUTPUT CHARACTERISTICS

Differential Output Voltage Swing ∆V
Output Balance Error (∆V

OUT

OS,CM

)/∆V

OUT

43.8 44.2 44.6 V

60 dB
Linear Output Current RL = 10 Ω, fC = 100 kHz 400 mA
Worst harmonic = –60 dBc
Output Common-Mode Offset (V
Output Common-Mode Offset (V

+OUT

+OUT

+ V
+ V

–OUT

–OUT

)/2, V

= midsupply –75 ±35 +75 mV

OCM

)/2, V

= float –75 ±35 +75 mV

OCM

POWER SUPPLY

Operating Range (Dual Supply) ±5 ±12 V
Operating Range (Single Supply) +10 +24 V
Total Quiescent Current PWDN1, PWDN0 = (1,1); I
(1,0); I
(0,1); I
(0,0); I
Total Quiescent Current PWDN1, PWDN0 = (1,1); I
(1,0); I
(0,1); I
(0,0); I
Power Supply Rejection Ratio (PSRR) ∆V

/∆VS, ∆VS = ±1 V, V

OS,DM

= V

ADJ

EE

= V

ADJ

EE

= V

ADJ

EE

= V

ADJ

EE

= NC 10.0 11.0 mA

ADJ

= NC 6.7 8.0 mA

ADJ

= NC 3.8 5.0 mA

ADJ

= NC 0.67 1.0 mA

ADJ

= midsupply 70 76 dB

OCM

5.2 6.5 mA

3.8 5.0 mA

2.5 3.5 mA

0.57 1.0 mA

PWDN = 0 (Low Logic State) 1.0 V
PWDN = 1 (High Logic State) 1.6 V

V

OCM

TO ±V

SPECIFICATIONS

OUT

Input Voltage Range –11.0 to +10.0 V
Input Resistance 28 kΩ
V

Accuracy ∆V

OCM

1

V

bypassed with 0.1 µF capacitor.

OCM

2

See . Figure 3

OUT,CM

/∆V

OCM

0.996 1.0 1.004 V/V

1, 2

Rev. C | Page 3 of 16

AD8390

VS = ±5 V or +10 V, RL = 100 Ω, G = 10, PWDN = (1,1), I

= NC, V

ADJ

= float, TA = 25°C, unless otherwise noted.

OCM

1, 2

Table 2.
Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

–3 dB Small Signal Bandwidth V
Large Signal Bandwidth V
Peaking V
Slew Rate V

= 0.2 V p-p, RF = 10 kΩ, G = 10 40 60 MHz

OUT

= 4 V p-p 25 40 MHz

OUT

= 0.2 V p-p 0.1 dB

OUT

= 4 V p-p 300 V/µs

OUT

NOISE/DISTORTION PERFORMANCE

Second Harmonic Distortion fC = 1 MHz, V
Third Harmonic Distortion fC = 1 MHz, V

= 2 V p-p –82 dBc

OUT

= 2 V p-p –91 dBc

OUT

Voltage Noise (RTI) f = 10 kHz 8 nV/√Hz
Input Current Noise f = 10 kHz 1 pA/√Hz

INPUT CHARACTERISTICS

RTI Offset Voltage (V
RTI Offset Voltage (V

OS,DM(RTI)

OS,DM(RTI)

) V
) V

+IN

+IN

– V
– V

, V

= midsupply –3.0 ±1.0 +3.0 mV

–IN

OCM

, V

= float –3.0 ±1.0 +3.0 mV

–IN

OCM

±Input Bias Current –4.0 –7.0 µA
Input Offset Current –0.35 ±0.05 +0.35 µA
Input Resistance 400 kΩ
Input Capacitance 2 pF
Common-Mode Rejection Ratio (∆V

OS,DM(RTI)

)/(∆V

) 58 64 dB

IN,CM

OUTPUT CHARACTERISTICS

Differential Output Voltage Swing ∆V
Output Balance Error (∆V

OUT

OS,CM

)/∆V

OUT

16.0 16.4 16.8 V

60 dB
Linear Output Current RL = 10 Ω, fC = 100 kHz 400 mA
Worst harmonic = –60 dBc
Output Common-Mode Offset (V
Output Common-Mode Offset (V

+OUT

+OUT

+ V
+ V

–OUT

–OUT

)/2, V
)/2, V

= midsupply

OCM

= float

OCM

–75

–75

±35 +75 mV
±35 +75 mV

POWER SUPPLY

Operating Range (Dual Supply) ±5 ±12 V
Operating Range (Single Supply) +10 +24 V
Total Quiescent Current PWDN1, PWDN0 = (1,1); I
(1,0); I
(0,1); I
(0,0); I
Total Quiescent Current PWDN1, PWDN0 = (1,1); I
(1,0); I
(0,1); I
(0,0); I
Power Supply Rejection Ratio ∆V

/∆VS, ∆VS = ±1 V, V

OS,DM

= V

ADJ

EE

= V

ADJ

EE

= V

ADJ

EE

= V

ADJ

EE

= NC 8.7 10.0 mA

ADJ

= NC 5.8 7.0 mA

ADJ

= NC 3.3 4.0 mA

ADJ

= NC 0.55 1.0 mA

ADJ

= midsupply 70 76 dB

OCM

4.5 5.5 mA

3.3 4.0 mA

2.1 3.0 mA

0.43 1.0 mA

PWDN = 0 (Low Logic State) 1.0 V
PWDN = 1 (High Logic State) 1.6 V

V

OCM

TO ±V

SPECIFICATIONS

OUT

Input Voltage Range –4.0 to +3.0 V
Input Resistance 28 kΩ
V

Accuracy ∆V

OCM

1

V

bypassed with 0.1 µF capacitor.

OCM

2

See . Figure 3

OUT,CM

/∆V

OCM

0.996 1.0 1.004 V/V

Rev. C | Page 4 of 16

AD8390

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage ±13.2 V (26.4 V)
V

OCM

Package Power Dissipation (TJ
Maximum Junction Temperature (TJ

MAX

Operating Temperature Range (TA) –40°C to +85°C
Storage Temperature Range –65°C to +150°C
Lead Temperature (Soldering 10 s) 300°C

Stresses above those listed under Absolute Maximum Ratings

VEE < V

MAX

< V

OCM

– TA)/θ

) 150°C

CC

JA

TYPICAL THERMAL PROPERTIES

Table 4.

Package Typical Thermal Resistance (θJA)
16-lead LFCSP (CP-16)

JEDEC 2S2P – 0 airflow
Paddle soldered to board
Nine thermal vias in pad

16-lead QSOP/EP (RC-16)
JEDEC 1S2P – 0 airflow
Paddle soldered to board
Nine thermal vias in pad

may cause permanent 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 periods may affect
device reliability.

= 1kΩ

= 1kΩ

RF = 10kΩ

AD8390

RF = 10kΩ

Figure 3. Basic Test Circuit

R

L,DM

= 100Ω

V

49.9Ω
R

G

V

IN

R

G

49.9Ω

OUT,DM

03600-0-003

30.4°C/W

44.3°C/W

ESD 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 this product 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.

Rev. C | Page 5 of 16