ANALOG DEVICES ADA4861-3 Service Manual

High Speed, Low Cost,

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FEATURES

High speed

730 MHz, −3 dB bandwidth
625 V/μs slew rate

13 ns settling time to 0.5%
Wide supply range: 5 V to 12 V
Low power: 6 mA/amplifier

0.1 dB flatness: 100 MHz
Differential gain: 0.01%
Differential phase: 0.02°
Low voltage offset: 100 μV (typical)
High output current: 25 mA
Power down

APPLICATIONS

Consumer video
Professional video
Broadband video
ADC buffers
Active filters

GENERAL DESCRIPTION

The ADA4861-3 is a low cost, high speed, current feedback,
triple op amp that provides excellent overall performance. The
730 MHz, −3 dB bandwidth, and 625 V/μs slew rate make this
amplifier well suited for many high speed applications. With its
combination of low price, excellent differential gain (0.01%),
differential phase (0.02°), and 0.1 dB flatness out to 100 MHz,
this amplifier is ideal for both consumer and professional video
applications.

The ADA4861-3 is designed to operate on supply voltages as
lo

w as +5 V and up to ±5 V using only 6 mA/amplifier of supply
current. To further reduce power consumption, each amplifier
is equipped with a power-down feature that lowers the supply
current to 0.3 mA/amplifier when not being used.

The ADA4861-3 is available in a 14-lead SOIC_N package and

ned to work over the extended temperature range of

is desig

−40°C to +105°C.

Triple Op Amp

ADA4861-3

PIN CONFIGURATION

+V

+IN 1

–IN 1

OUT 1

1

2

3

4

S

5

6

7

ADA4861-3

POWER DOW N 1

POWER DOW N 2

POWER DOW N 3

Figure 1.

6.1

6.0

5.9

5.8

5.7

5.6

5.5

5.4

CLOSED-LOOP GAIN (dB)

5.3

5.2

5.1

0.1 1 10 100 1000

FREQUENCY (MHz)

Figure 2. Large Signal 0.1 dB Flatness

VS = +5V

14

13

12

11

10

9

8

OUT 2

–IN 2

+IN 2

–V

S

+IN 3

–IN 3

OUT 3

G = +2
V

OUT

R

= RG = 301Ω

F

05708-001

= 2V p-p

= ±5V

V

S

05708-011

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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] www.analog.com
Fax: [phone] ©2006 Analog Devices, Inc. All rights reserved.

ADA4861-3

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TABLE OF CONTENTS

Features.............................................................................................. 1

Gain Configurations .................................................................. 13

Applications....................................................................................... 1

Pin Configuration............................................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 2

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

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

Thermal Resistance ...................................................................... 5

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

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

Applications..................................................................................... 13

REVISION HISTORY

3/06—Rev 0 to Rev. A

Changes to 20 MHz Active Low-Pass Filter Section.................. 13

Changes to Figure 48 and Figure 49............................................. 13

10/05—Revision 0: Initial Version

20 MHz Active Low-Pass Filter................................................ 13

RGB Video Driver...................................................................... 14

Driving Two Video Loads ......................................................... 14

POWER-DOWN Pins ............................................................... 14

Single-Supply Operation........................................................... 15

Power Supply Bypassing............................................................ 15

Layout .......................................................................................... 15

Outline Dimensions....................................................................... 16

Ordering Guide .......................................................................... 16

Rev. A | Page 2 of 16

ADA4861-3

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SPECIFICATIONS

VS = +5 V (@ TA = 25°C, G = +2, RL = 150 Ω, CL = 4 pF, unless otherwise noted); for G = +2, RF = RG = 301 Ω; and for G = +1, RF = 499 Ω.

Table 1.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

–3 dB Bandwidth VO = 0.2 V p-p 350 MHz
V
G = +1, VO = 0.2 V p-p 560 MHz

Bandwidth for 0.1 dB Flatness VO = 2 V p-p 85 MHz

+Slew Rate (Rising Edge) VO = 2 V p-p 590 V/μs

−Slew Rate (Falling Edge) VO = 2 V p-p 480 V/μs

Settling Time to 0.5% (Rise/Fall) VO = 2 V step 12/13 ns
NOISE/DISTORTION PERFORMANCE

Harmonic Distortion HD2/HD3 fC = 1 MHz, VO = 2 V p-p −81/−89 dBc

Harmonic Distortion HD2/HD3 fC = 5 MHz, VO = 2 V p-p −69/−76 dBc

Input Voltage Noise f = 100 kHz 3.8 nV/√Hz

Input Current Noise f = 100 kHz, +IN/−IN 1.7/5.5 pA/√Hz

Differential Gain 0.02 %

Differential Phase 0.03 Degrees

All-Hostile Crosstalk

DC PERFORMANCE

Input Offset Voltage −13 −0.9 +13 mV

+Input Bias Current

−Input Bias Current −8 +2.3 +13 μA

Open-Loop Transresistance 400 620 kΩ
INPUT CHARACTERISTICS

Input Resistance +IN 14 MΩ

−IN 85 Ω

Input Capacitance +IN 1.5 pF

Input Common-Mode Voltage Range G = +1 1.2 to 3.8 V

Common-Mode Rejection Ratio VCM = 2 V to 3 V −54 −56.5 dB
POWER-DOWN PINS

Input Voltage Enabled 0.6 V

Power down 1.8 V

Bias Current Enabled −3 μA

Power down 115 μA

Turn-On Time 200 ns

Turn-Off Time 3.5 μs
OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = +2.25 V to −0.25 V 55/100 ns

Output Voltage Swing RL = 150 Ω 1.2 to 3.8 1.1 to 3.9 V

R

Short-Circuit Current Sinking and sourcing 65 mA
POWER SUPPLY

Operating Range 5 12 V

Total Quiescent Current Enabled 12.5 16.1 18.5 mA

Quiescent Current/Amplifier POWER DOWN pins = +VS 0.2 0.33 mA

Power Supply Rejection Ratio

+PSR +VS = 4 V to 6 V, −VS = 0 V −60 −64 dB

= 2 V p-p 145 MHz

O

Amplifier 1 and Amplifier 2 driven,
Amplifier 3 output measur

−2 −0.8 +1 μA

= 1 kΩ 0.9 to 4.1 0.85 to 4.15 V

L

ed, f = 1 MHz

−65 dB

Rev. A | Page 3 of 16

ADA4861-3

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VS = ±5 V (@ TA = 25°C, G = +2, RL = 150 Ω, CL = 4 pF, unless otherwise noted); for G = +2, RF = RG = 301 Ω; and for G = +1, RF = 499 Ω.

Table 2.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

–3 dB Bandwidth VO = 0.2 V p-p 370 MHz
V
G = +1, VO = 0.2 V p-p 730 MHz

Bandwidth for 0.1 dB Flatness VO = 2 V p-p 100 MHz

+Slew Rate (Rising Edge) VO = 2 V p-p 910 V/μs

−Slew Rate (Falling Edge) VO = 2 V p-p 680 V/μs

Settling Time to 0.5% (Rise/Fall) VO = 2 V step 12/13 ns
NOISE/DISTORTION PERFORMANCE

Harmonic Distortion HD2/HD3 fC = 1 MHz, VO = 2 V p-p −85/−99 dBc

Harmonic Distortion HD2/HD3 fC = 5 MHz, VO = 2 V p-p −73/−86 dBc

Input Voltage Noise f = 100 kHz 3.8 nV/√Hz

Input Current Noise f = 100 kHz, +IN/−IN 1.7/5.5 pA/√Hz

Differential Gain 0.01 %

Differential Phase 0.02 Degrees

All-Hostile Crosstalk

DC PERFORMANCE

Input Offset Voltage −13 −0.1 +13 mV

+Input Bias Current

−Input Bias Current −8 +2.9 +13 μA

Open-Loop Transresistance 500 720 kΩ
INPUT CHARACTERISTICS

Input Resistance +IN 15 MΩ

−IN 90 Ω

Input Capacitance +IN 1.5 pF

Input Common-Mode Voltage Range G = +1 −3.7 to +3.7 V

Common-Mode Rejection Ratio VCM = ±2 V −55 −58 dB
POWER-DOWN PINS

Input Voltage Enabled −4.4 V

Power down −3.2 V

Bias Current Enabled −3 μA

Power down 250 μA

Turn-On Time 200 ns

Turn-Off Time 3.5 μs
OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = ±3.0 V 30/90 ns

Output Voltage Swing RL = 150 Ω ±2 −3.1 to +3.65 V

R

Short-Circuit Current Sinking and sourcing 100 mA
POWER SUPPLY

Operating Range 5 12 V

Total Quiescent Current Enabled 13.5 17.9 20.5 mA

Quiescent Current/Amplifier POWER DOWN pins = +VS 0.3 0.5 mA

Power Supply Rejection Ratio

+PSR +VS = 4 V to 6 V, −VS = −5 V −63 −66 dB

−PSR

= 2 V p-p 210 MHz

O

Amplifier 1 and Amplifier 2 driven,
Amplifier 3 output measur

−2 −0.7 +1 μA

= 1 kΩ ±3.9 ±4.05 V

L

= 5 V, −VS = −4 V to −6 V,

+V

S

POWER DOWN pins = −V

ed, f = 1 MHz

S

−65 dB

−59 −62 dB

Rev. A | Page 4 of 16

ADA4861-3

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ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage 12.6 V
Power Dissipation See Figure 3
Common-Mode Input Voltage −VS + 1 V to +VS − 1 V
Differential Input Voltage ±VS
Storage Temperature −65°C to +125°C
Operating Temperature Range −40°C to +105°C
Lead Temperature JEDEC J-STD-20
Junction Temperature 150°C

Stresses above those listed under Absolute Maximum Ratings

y cause permanent damage to the device. This is a stress

ma
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.

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, θJA is
specified for device soldered in circuit board for surface-mount
packages.

Table 4. Thermal Resistance

Package Type θJA Unit

14-lead SOIC_N 90 °C/W

Maximum Power Dissipation

The maximum safe power dissipation for the ADA4861-3 is
limited by the associated rise in junction temperature (T
the die. At approximately 150°C, which is the glass transition
temperature, the plastic changes its properties. Even temporarily
exceeding this temperature limit can change the stresses that the
package exerts on the die, permanently shifting the parametric
performance of the amplifiers. Exceeding a junction temperature of
150°C for an extended period can result in changes in silicon
devices, potentially causing degradation or loss of functionality.

) on

J

The power dissipated in the package (P
quiescent power dissipation and the power dissipated in the die
due to the amplifiers’ drive at the output. The quiescent power
is the voltage between the supply pins (V
current (I

).

S

= Quiescent Power + (Total Drive Power − Load Power)

P

D

VV

⎛

S

()

D

IVP

SS

OUT

×+×=

⎜

2

R

⎝

L

RMS output voltages should be considered.

Airflow increases heat dissipation, effectively reducing θ
In addition, more metal directly in contact with the package
leads and through holes under the device reduces θ

Figure 3 shows the maximum safe power dissipation in the

ackage vs. the ambient temperature for the 14-lead SOIC_N

p
(90°C/W) on a JEDEC standard 4-layer board. θ
approximations.

2.5

2.0

1.5

1.0

0.5

MAXIMUM POW ER DISSIPAT ION (W)

0

–55 125–45–35–25–15–5 5 152535455565758595105115

AMBIENT TEMPERATURE (°C)

Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board

) is the sum of the

D

) times the quiescent

S

2

V

⎞

OUT

–

⎟

R

L

⎠

.

JA

values are

JA

.

JA

05708-002

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. A | Page 5 of 16