ANALOG DEVICES ADA4851-1, ADA4851-2, ADA4851-4 Service Manual

V

查询ADA4850-1供应商

Low Cost, High Speed,

FEATURES

High speed

130 MHz, −3 dB bandwidth
375 V/μs slew rate
55 ns settling time to 0.1%

Excellent video specifications

0.1 dB flatness: 11 MHz
Differential gain: 0.08%

Differential phase: 0.09°
Fully specified at +3 V, +5 V, and ±5 V supplies
Rail-to-rail output

Output swings to within 60 mV of either rail
Low voltage offset: 0.6 mV
Wide supply range: 3 V to 10 V
Low power: 2.5 mA/amplifier
Power-down mode
Available in space-saving packages

SOT-23-6, TSSOP-14, and MSOP-8

APPLICATIONS

Consumer video
Professional video
Video switchers
Active filters

Rail-to-Rail Output Op Amps

ADA4851-1/ADA4851-2/ADA4851-4

PIN CONFIGURATIONS

ADA4851-1

1

V

OUT

2

–V

S

3

+IN

TOP VIEW (Not to Scale)

Figure 1. ADA4851-1, 6-Lead SOT-23 (RJ-6)

ADA4851-2

1

OUT1

–IN1

2
3

+IN1

–V

4

S

TOP VIEW

(Not to Scale)

Figure 2. ADA4851-2, 8-Lead MSOP (RM-8)

1

V

1

OUT

2

–IN 1

3

+IN 1

+V
+IN 2
–IN 2

OUT

S

2

ADA4851-4

4

(Not to Scale)

5

6

7

TOP VIEW

Figure 3. ADA4851-4, 14-Lead TSSOP (RU-14)

+V

6

S

5

POWER DOWN

4

–IN

8

+V
OUT

7
6

–IN2
+IN2

5

14

V

13

–IN 4

12

+IN 4

11

–V
+IN 3

10

9

–IN 3

8

V

S

OUT

OUT

S

05143-058

4

3

05143-001

05143-054

GENERAL DESCRIPTION

The ADA4851-1 (single)/ADA4851-2 (dual)/ADA4851-4
(quad) are low cost, high speed, voltage feedback rail-to-rail
output op amps. Despite their low price, these parts provide
excellent overall performance and versatility. The 130 MHz,

−3 dB bandwidth and high slew rate make these amplifiers well­suited for many general-purpose, high speed applications.

The ADA4851 family is designed to operate at supply voltages
as low as +3 V and up to ±5 V. These parts provide true single­supply capability, allowing input signals to extend 200 mV
below the negative rail and to within 2.2 V of the positive rail.
On the output, the amplifiers can swing within 60 mV of either
supply rail.

With their combination of low price, excellent differential gain
(0.08%), differential phase (0.09º), and 0.1 dB flatness out to
11 MHz, these amplifiers are ideal for consumer video
applications.

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 Anal og Devices. Trademarks and
registered trademarks are the property of their respective owners.

The ADA4851 family is designed to work over the extended
temperature range (−40°C to +125°C).

4

G = +1
V

= 5V

3

S

R

= 1kΩ

L

C

= 5pF

2

L

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

–5

–6

1 10010 1k

FREQUENCY (MHz)

Figure 4. Small S ignal Freq uency Respons e

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2005 Analog Devices, Inc. All rights reserved.

05143-004

ADA4851-1/ADA4851-2/ADA4851-4

TABLE OF CONTENTS

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

Typical Perform anc e C ha r a cte ristics ..............................................7

Specifications with +3 V Supply................................................. 3

Specifications with +5 V Supply................................................. 4

Specifications with ±5 V Supply................................................. 5

Absolute Maximum Ratings............................................................ 6

Thermal Resistance ...................................................................... 6

ESD Caution.................................................................................. 6

REVISION HISTORY

5/05—Rev. B to Rev. C

Changes to General Description .................................................... 1

Changes to Input Section............................................................... 14

4/05—Rev. A to Rev. B

Added ADA4851-2.............................................................Universal

Added 8-Lead MSOP ......................................................... Universal

Changes to Features.......................................................................... 1

Changes to General Description .................................................... 1

Changes to Table 1............................................................................ 3

Changes to Table 2............................................................................ 4

Changes to Table 3............................................................................ 5

Changes to Table 4 and Figure 5..................................................... 6

Changes to Figure 12, Figure 15, and Figure 17 ........................... 8

Changes to Figure 18........................................................................ 9

Changes to Figure 28 Caption....................................................... 10

Changes to Figure 33...................................................................... 11

Changes to Figure 36 and Figure 38............................................. 12

Added Figure 39.............................................................................. 12

Changes to Circuit Description Section...................................... 13

Changes to Headroom Considerations Section ......................... 13

Changes to Overload Behavior and Recovery Section ..............14

Added Single-Supply Video Amplifier Section .......................... 15

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

Changes to Ordering Guide.......................................................... 17

Circuit Description......................................................................... 13

Headroom Considerations........................................................ 13

Overload Behavior and Recovery ............................................ 14

Single-Supply Video Amplifier................................................. 15

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

Ordering Guide .......................................................................... 17

1/05—Rev. 0 to Rev. A

Added ADA4851-4.............................................................Universal

Added 14-Lead TSSOP...................................................... Universal

Changes to Features ..........................................................................1

Changes to General Description .....................................................1

Changes to Figure 3...........................................................................1

Changes to Specifications.................................................................3

Changes to Figure 4...........................................................................6

Changes to Figure 8...........................................................................7

Changes to Figure 11.........................................................................8

Changes to Figure 22.........................................................................9

Changes to Figure 23, Figure 24, and Figure 25......................... 10

Changes to Figure 27 and Figure 28............................................. 10

Changes to Figure 29, Figure 30, and Figure 31......................... 11

Changes to Figure 34...................................................................... 11

Added Figure 37 ............................................................................. 12

Changes to Ordering Guide.......................................................... 15

Updated Outline Dimensions....................................................... 15

10/04—Revision 0: Initial Version

Rev. C | Page 2 of 20

ADA4851-1/ADA4851-2/ADA4851-4

SPECIFICATIONS

SPECIFICATIONS WITH +3 V SUPPLY

TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.

Table 1.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth G = +1, VO = 0.1 V p-p 104 130 MHz

G = +1, VO = 0.5 V p-p 80 105 MHz

G = +2, VO = 1.0 V p-p, RL = 150 Ω 40 MHz
Bandwidth for 0.1 dB Flatness G = +2, VO = 1 V p-p, RL = 150 Ω 15 MHz
Slew Rate G = +2, VO = 1 V step 100 V/μs
Settling Time to 0.1% G = +2, VO = 1 V step, RL = 150 Ω 50 ns

NOISE/DISTORTION PERFORMANCE

Harmonic Distortion (dBc) HD2/HD3 fC = 1 MHz, VO = 1 V p-p, G = −1 −73/−79 dBc
Input Voltage Noise f = 100 kHz 10 nV/√Hz
Input Current Noise f = 100 kHz 2.5 pA/√Hz
Differential Gain G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p 0.44 %
Differential Phase G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p 0.41 Degrees
Crosstalk (RTI)—ADA4851-2/ADA4851-4 f = 5 MHz, G = +2, VO = 1.0 V p-p −70/−60 dB

DC PERFORMANCE

Input Offset Voltage 0.6 3.3 mV
Input Offset Voltage Drift 4 μV/°C
Input Bias Current
Input Bias Current Drift 6 nA/°C
Input Bias Offset Current 20 nA
Open-Loop Gain VO = 0.25 V to 0.75 V 80 105 dB

INPUT CHARACTERISTICS

Input Resistance Differential/common-mode 0.5/5.0 MΩ
Input Capacitance 1.2 pF
Input Common-Mode Voltage Range −0.2 to +0.8 V
Input Overdrive Recovery Time (Rise/Fall) VIN = +3.5 V, −0.5 V, G = +1 60/60 ns
Common-Mode Rejection Ratio VCM = 0 V to 0.5 V −81 −103 dB

POWER-DOWN

Power-Down Input Voltage Power-down <1.1 V

Enabled >1.6 V

Turn-Off Time 0.7 μs
Turn-On Time 60 ns
Power-Down Bias Current

Enabled Power-down = 3 V 4 6 μA
Power-Down Power-down = 0 V −14 −20 μA

OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = +0.7 V, −0.1 V, G = +5 70/100 ns
Output Voltage Swing 0.05 to 2.91 0.03 to 2.94 V
Short-Circuit Current Sinking/sourcing 90/70 mA

POWER SUPPLY

Operating Range 2.7 12 V
Quiescent Current per Amplifier 2.4 2.7 mA
Quiescent Current (Power-Down) Power-down = low 0.2 0.3 mA
Positive Power Supply Rejection +VS = +2.5 V to +3.5 V, −VS = −0.5 V −81 −100 dB
Negative Power Supply Rejection +VS = +2.5 V, −VS = −0.5 V to –1.5 V −80 −100 dB

2.3 4.0 μA

Rev. C | Page 3 of 20

ADA4851-1/ADA4851-2/ADA4851-4

SPECIFICATIONS WITH +5 V SUPPLY

TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.

Table 2.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth G = +1, VO = 0.1 V p-p 96 125 MHz

G = +1, VO = 0.5 V p-p 72 96 MHz

G = +2, VO = 1.4 V p-p, RL = 150 Ω 35 MHz
Bandwidth for 0.1 dB Flatness G = +2, VO = 1.4 V p-p, RL = 150 Ω 11 MHz
Slew Rate G = +2, VO = 2 V step 200 V/μs
Settling Time to 0.1% G = +2, VO = 2 V step, RL = 150 Ω 55 ns

NOISE/DISTORTION PERFORMANCE

Harmonic Distortion (dBc) HD2/HD3 fC = 1 MHz, VO = 2 V p-p, G = +1 −80/−100 dBc
Input Voltage Noise f = 100 kHz 10 nV/√Hz
Input Current Noise f = 100 kHz 2.5 pA/√Hz
Differential Gain G = +2, NTSC, RL = 150 Ω, VO = 2 V p-p 0.08 %
Differential Phase G = +2, NTSC, RL = 150 Ω, VO = 2 V p-p 0.11 Degrees
Crosstalk (RTI)—ADA4851-2/ADA4851-4 f = 5 MHz, G = +2, VO = 2.0 V p-p −70/−60 dB

DC PERFORMANCE

Input Offset Voltage 0.6 3.4 mV
Input Offset Voltage Drift 4 μV/°C
Input Bias Current
Input Bias Current Drift 6 nA/°C
Input Bias Offset Current 20 nA
Open-Loop Gain VO = 1 V to 4 V 97 107 dB

INPUT CHARACTERISTICS

Input Resistance Differential/common-mode 0.5/5.0 MΩ
Input Capacitance 1.2 pF
Input Common-Mode Voltage Range −0.2 to +2.8 V
Input Overdrive Recovery Time (Rise/Fall) VIN = +5.5 V, −0.5 V, G = +1 50/45 ns
Common-Mode Rejection Ratio VCM = 0 V to 2 V −86 −105 dB

POWER-DOWN

Power-Down Input Voltage Power-down <1.1 V

Enabled >1.6 V

Turn-Off Time 0.7 μs
Turn-On Time 50 ns
Power-Down Bias Current

Enabled Power-down = 5 V 33 40 μA
Power-Down Power-down = 0 V −22 −30 μA

OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = +1.1 V, −0.1 V, G = +5 60/70 ns
Output Voltage Swing 0.09 to 4.91 0.06 to 4.94 V
Short-Circuit Current Sinking/sourcing 110/90 mA

POWER SUPPLY

Operating Range 2.7 12 V
Quiescent Current per Amplifier 2.5 2.8 mA
Quiescent Current (Power-Down) Power-down = low 0.2 0.3 mA
Positive Power Supply Rejection +VS = +5 V to +6 V, −VS = 0 V −82 −101 dB
Negative Power Supply Rejection +VS = +5 V, −VS = −0 V to −1 V −81 −101 dB

2.2 3.9 μA

Rev. C | Page 4 of 20

ADA4851-1/ADA4851-2/ADA4851-4

SPECIFICATIONS WITH ±5 V SUPPLY

TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.

Table 3.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth G = +1, VO = 0.1 V p-p 83 105 MHz

G = +1, VO = 1 V p-p 52 74 MHz

G = +2, VO = 2 V p-p, RL = 150 Ω 40 MHz
Bandwidth for 0.1 dB Flatness G = +2, VO = 2 V p-p, RL = 150 Ω 11 MHz
Slew Rate G = +2, VO = 7 V step 375 V/μs
G = +2, VO = 2 V step 190 V/μs
Settling Time to 0.1% G = +2, VO = 2 V step, RL = 150 Ω 55 ns

NOISE/DISTORTION PERFORMANCE

Harmonic Distortion (dBc) HD2/HD3 fC = 1 MHz, VO = 2 V p-p, G = +1 −83/−107 dBc
Input Voltage Noise f = 100 kHz 10 nV/√Hz
Input Current Noise f = 100 kHz 2.5 pA/√Hz
Differential Gain G = +2, NTSC, RL = 150 Ω, VO = 2 V p-p 0.08 %
Differential Phase G = +2, NTSC, RL = 150 Ω, VO = 2 V p-p 0.09 Degrees
Crosstalk(RTI)—ADA4851-2/ADA4851-4 f = 5 MHz, G = +2, VO = 2.0 V p-p −70/−60 dB

DC PERFORMANCE

Input Offset Voltage 0.6 3.5 mV
Input Offset Voltage Drift 4 μV/°C
Input Bias Current
Input Bias Current Drift 6 nA/°C
Input Bias Offset Current 20 nA
Open-Loop Gain

INPUT CHARACTERISTICS

Input Resistance Differential/common-mode 0.5/5.0 MΩ
Input Capacitance 1.2 pF
Input Common-Mode Voltage Range −5.2 to +2.8 V
Input Overdrive Recovery Time (Rise/Fall) VIN = ±6 V, G = +1 50/25 ns
Common-Mode Rejection Ratio VCM = 0 V to 4 V −90 −105 dB

POWER-DOWN

Power-Down Input Voltage Power-down < −3.9 V
Enabled > −3.4 V
Turn-Off Time 0.7 μs
Turn-On Time 30 ns
Power-Down Bias Current

Enabled Power-down = +5 V 100 130 μA
Power-Down Power-down = −5 V −50 −60 μA

OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = ±1.2 V, G = +5 80/50 ns
Output Voltage Swing −4.87 to +4.88 −4.92 to +4.92 V
Short-Circuit Current Sinking/sourcing 125/110 mA

POWER SUPPLY

Operating Range 2.7 12 V
Quiescent Current per Amplifier 2.9 3.2 mA
Quiescent Current (Power-Down) Power-down = low 0.2 0.3 mA
Positive Power Supply Rejection +VS = +5 V to +6 V, −VS = −5 V −82 −101 dB
Negative Power Supply Rejection +VS = +5 V, −VS = −5 V to −6 V −81 −102 dB

2.2 4.0 μA

= ±2.5 V

V

O

99 106 dB

Rev. C | Page 5 of 20

ADA4851-1/ADA4851-2/ADA4851-4

(

)

ABSOLUTE MAXIMUM RATINGS

Table 4.

Parameter Rating

Supply Voltage 12.6 V
Power Dissipation See Figure 5
Common-Mode Input Voltage −VS − 0.5 V to +VS + 0.5 V
Differential Input Voltage +VS to −V

S

Storage Temperature −65°C to +125°C
Operating Temperature Range −40°C to +125°C
Lead Temperature Range JEDEC J-STD-20
Junction Temperature 150°C

Stresses above those listed under Absolute Maximum Ratings
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.

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 5. Thermal Resistance

Package Type θ

JA

Unit

6-lead SOT-23 170 °C/W
14-lead TSSOP 120 °C/W
8-lead MSOP 150 °C/W

Maximum Power Dissipation

The maximum safe power dissipation for the ADA4851-1/
ADA4851-2/ADA4851-4 is limited by the associated rise in
junction temperature (T

) on the die. At approximately 150°C,

J

which is the glass transition temperature, the plastic changes its
properties. Even temporarily exceeding this temperature limit
may 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 of time can result in changes in silicon devices,
potentially causing degradation or loss of functionality.

The power dissipated in the package (P

) is the sum of the

D

quiescent power dissipation and the power dissipated in the die

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.

due to the amplifiers’ drive at the output. The quiescent power

is the voltage between the supply pins (V

current (I

).

S

= Quiescent Power + (Tot a l Dr i v e Pow e r − Load Power)

P

D

()

D

IVP

SS

VV

⎛

S

×+×=

⎜

2

⎝

OUT

R

V

⎞

–

⎟

L

⎠

RMS output voltages should be considered. If RL is referenced

, as in single-supply operation, the total drive power is

to −V

S

× I

V

worst case, when V

In single-supply operation with R

is V

. If the rms signal levels are indeterminate, consider the

S

OUT

= VS/4 for RL to midsupply.

OUT

2

V

4/

()

D

= VS/2.

OUT

S

IVP

+×=

SS

R

L

referenced to −VS, worst case

L

Airflow increases heat dissipation, effectively reducing θ

Also, more metal directly in contact with the package leads and

through holes under the device reduces θ

Figure 5 shows the maximum safe power dissipation in the

package vs. the ambient temperature for the 6-lead SOT-23

(170°C/W), the 8-lead MSOP (150°C/W), and the 14-lead

TSSOP (120°C/W) on a JEDEC standard 4-layer board. θ

values are approximations.

2.0

TSSOP

1.5

MSOP

1.0

0.5

MAXIMUM POWER DISSIPATION (W)

0

–55 125

Figure 5. Maximum Power Dissipation vs. Temperature for a 4-Layer Board

SOT-23-6

–45 –35 –25 –15 –5 5 15 25 35 45 55 65 75 85 95 105 115

AMBIENT TEMPERATURE (°C)

) times the quiescent

S

2

OUT

R

L

.

JA

.

JA

JA

05143-057

Rev. C | Page 6 of 20

ADA4851-1/ADA4851-2/ADA4851-4

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.

1

0

–1

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

–7

1 10010

G = +10

FREQUENCY (MHz)

G = +2

VS = ±5V
R

= 150Ω

L

V

OUT

G = –1

Figure 6. Small Signal Frequency Response for Various Gains

= 0.1V p-p

05143-006

4

G = +1
V

= 5V

3

S

R

= 1kΩ

L

V

= 0.1V p-p

2

OUT

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

–5

–6

1 10010 300

FREQUENCY (MHz)

5pF

0pF

10pF

Figure 9. Small Signal Frequency Response for Various Capacitor Loads

05143-010

1

0

VS = ±5V

–1

G = +1
V

= 0.1V p-p

OUT

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

1 10010 300

FREQUENCY (MHz)

R

L

RL = 150Ω

= 1kΩ

Figure 7. Small Signal Frequency Response for Various Loads

2

G = +1
R

= 150Ω

L

1

V

= 0.1V p-p

OUT

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

–5

–6

1 10010 300

FREQUENCY (MHz)

V

= ±5V

S

V

= +5V

S

Figure 8. Small Signal Frequency Response for Various Supplies

05143-009

05143-007

1

0

VS = ±5V

–1

G = +1
V

= 0.1V p-p

OUT

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

1 10010

–40°C

+25°C

FREQUENCY (MHz)

+125°C

+85°C

300

Figure 10. Small Signal Frequency Response for Various Temperatures

1

0

–1

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

–7

1 10010

G = +10

FREQUENCY (MHz)

G = –1

VS = ±5V
R

= 150Ω

L

V

= 1V p-p

OUT

G = +2

Figure 11. Large Signal Frequency Response for Various Gains

05143-008

05143-012

Rev. C | Page 7 of 20

ADA4851-1/ADA4851-2/ADA4851-4

–

6.2

6.1

6.0

5.9

5.8

5.7

CLOSED-LOOP GAIN (dB)

5.6

V

= 100mV p-p

OUT

V

OUT

= 1V p-p

V

OUT

= 2V p-p

5.5

VS = ±5V
G = +2

= 150Ω

R

L

= 1kΩ

R

F

–40

G = –1
V

–50

R
V

–60

–70

–80

DISTORTION (dBc)

–90

–100

= 3V

S

= 150Ω

L

= 2V

OUT

HD2

HD3

5.4

0.1 100

110

FREQUENCY (MHz)

Figure 12. 0.1 dB Flatness Response

1

0

–1

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

1 10010 300

FREQUENCY (MHz)

R

L

= 150Ω

VS = ±5V
G = +1
V

= 1V p-p

OUT

R

= 1kΩ

L

Figure 13. Large Frequency Response for Various Loads

140

120

100

80

60

40

OPEN-LOOP GAIN (dB)

20

0

PHASE

GAIN

VS = ±5V

0

–30

–60

–90

–120

–150

–180

–210

05143-021

05143-015

OPEN-LOOP PHASE (Degrees)

–110

0.1 10

1

FREQUENCY (MHz)

Figure 15. Harmonic Distortion vs. Frequency

50

G = +2
V

= ±5V

S

–60

R

= 1kΩ

L

f = 2MHz

–70

–80

–90

–100

HARMONIC DISTORTION (dBc)

–110

–120

012345678910

HD2

HD3

OUTPUT AMPLITUDE (V p-p)

Figure 16. Harmonic Distortion vs. Output Voltage

–40

G = +1
V

= 2V p-p

OUT

–50

V

= ±5V

S

–60

–70

–80

–90

HARMONIC DISTORTION (dBc)

–100

RL = 150Ω HD2

RL = 1kΩ HD2

RL = 150Ω HD3

RL = 1kΩ HD3

05143-014

05143-017

–20

100k10k100 1k10 1M 10M 100M 1G

FREQUENCY (Hz)

Figure 14. Open-Loop Gain and Phase vs. Frequency

–240

05143-029

–110

0.1 10

1

FREQUENCY (MHz)

Figure 17. Harmonic Distortion vs. Frequency for Various Loads

05143-016

Rev. C | Page 8 of 20

ADA4851-1/ADA4851-2/ADA4851-4

–40

–50

G = +1
V

OUT

V

= 5V

S

= 2V p-p

0.075

0.050

G = +1 OR +2

= 1kΩ

R

L

2.575

2.550

–60

RL = 1kΩ HD2

–70

–80

RL = 150Ω HD2

RL = 150Ω HD3

–90

HARMONIC DISTORTION (dBc)

–100

–110

0.1 10

RL = 1kΩ HD3

1

FREQUENCY (MHz)

Figure 18. Harmonic Distortion vs. Frequency for Various Loads

6
5
4
3
2
1

0
–1
–2
–3

INPUT AND OUTPUT VOLTAGE (V)

–4
–5
–6

0 100 200 300 400 500 600 700 800 900 1k

5 × INPUT

OUTPUT

TIME (ns)

G = +5
V
R
f = 1MHz

Figure 19. Output Overdrive Recovery

= ±5V

S

= 150Ω

L

05143-013

05143-019

0.025

0

–0.025

–0.050

OUTPUT VOLTAGE FOR ±5V SUPPLY (V)

–0.075

VS = +5V

500 100 150 200

TIME (ns)

V

= ±5V

S

Figure 21. Small Signal Transient Response for Various Supplies

2.575
G = +1
V

= 5V

S

R

= 150Ω

L

2.550

2.525

2.500

2.475

OUTPUT VOLTAGE (V)

2.450

2.425

0 20 40 60 80 100 120 140 160 180 200

10pF

0pF

TIME (ns)

Figure 22. Small Signal Transient Response for Capacitive Load

2.525

2.500

2.475

2.450

2.425

OUTPUT VOLTAGE FOR 5V SUPPLY (V)

05143-024

05143-026

6
5
4
3
2
1

0
–1
–2
–3

INPUT AND OUTPUT VOLTAGE (V)

–4
–5
–6

OUTPUT

0 100 200 300 400 500 600 700 800 900 1k

INPUT

TIME (ns)

Figure 20. Input Overdrive Recovery

G = +1
V

= ±5V

S

R

= 150Ω

L

f = 1MHz

05143-022

Rev. C | Page 9 of 20

1.5
G = +2

= 150Ω

R

L

1.0

V

= ±5V

S

0.5

0

–0.5

–1.0

OUTPUT VOLTAGE FOR ±5V SUPPLY (V)

–1.5

VS = +5V

500 100 150 200

TIME (ns)

Figure 23. Large Signal Transient Response for Various Supplies

3.0

2.5

2.0

1.5

1.0

0.5

0

OUTPUT VOLTAGE FOR 5V SUPPLY (V)

05143-028

ADA4851-1/ADA4851-2/ADA4851-4

1.5
G = +1

R

= 150Ω

L

1.0
V

0.5

–0.5

= ±5V

S

0

VS = +5V

3.0

2.5

2.0

1.5

1.0

6

5

V

4

3

2

VOLTAGE (V)

1

DISABLE

G = +2
V

= 5V

S

f

= 400kHz

IN

–1.0

OUTPUT VOLTAGE FOR ±5V SUPPLY (V)

–1.5

500 100 150 200

TIME (ns)

Figure 24. Large Signal Transient Response for Various Supplies

0.5

(V)

S

0.4

0.3

0.2

0.1

DC VOLTAGE DIFFERENTIAL FROM V

0

0 5 10 15 20 25 30 35

LOAD CURRENT (mA)

+VS– V

VS = +3V

OUT

V

–V

– V

S

Figure 25. Output Saturation Voltage vs. Load Current

600

G = +2
V

= ±5V

S

R

= 1kΩ

L

500

400

300

200

SLEW RATE (V/μs)

100

25% TO 75% OF V

NEGATIVE SLEW RATE

O

POSITIVE SLEW RATE

S

OUT

= ±5V

0.5

0

OUTPUT VOLTAGE FOR 5V SUPPLY (V)

05143-027

05143-049

0

–1

03015 45

V

OUT

TIME (μs)

Figure 27. Enable/Disable Time

3.5

3.0

2.5

2.0

1.5

1.0

SUPPLY CURRENT (mA)

0.5

0

–5 –4 –3 –2 –1 0 1 2 3 4 5

Figure 28. ADA4851-1, Supply Current vs.

300

200

100

0

–100

–200

INPUT OFFSET VOLTAGE (μV)

–300

VS = ±5V

DISABLE VOLTAGE (V)

VS = ±5V

V

V

= +5V

S

= +5V

S

POWER DOWN

VS = +3V

V

= +3V

S

Pin Voltage

05143-033

05143-034

0

0123456789

OUTPUT VOLTAGE STEP (V p-p)

Figure 26. Slew Rate vs. Output Voltage

10

05143-032

Rev. C | Page 10 of 20

–400

–40 –25 –10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

Figure 29. Input Offset Voltage vs. Temperature for Various Supplies

05143-035

ADA4851-1/ADA4851-2/ADA4851-4

2.2

2.0

1000

G = +1

+, VS = ±5V

I

1.8

IB+, VS = +5V

1.6

INPUT BIAS CURRENT (μA)

1.4

1.2

–40 –25 –10 5 20 35 50 65 80 95 110 125

B

I

–, VS = +5V

B

TEMPERATURE (°C)

–, VS = ±5V

I

B

Figure 30. Input Bias Current vs. Temperature for Various Supplies

0.09

(V)

S

0.08

+VS– V

OUT

0.07

– V

0.06

0.05

DC VOLTAGE DIFFERENTIAL FROM V

0.04
–40 –25 –10 5 20 35 50 65 80 95 110 125

–V

S

OUT

VS = ±5V

+VS– V

OUT

–VS– V

TEMPERATURE (°C)

OUT

V

= +5V

S

Figure 31. Output Saturation vs. Temperature for Various Supplies

05143-036

05143-037

100

10

VOLTAGE NOISE (nV/ Hz)

1

100 1k 10k 100k 1M 10M

10 100M

FREQUENCY (Hz)

Figure 33. Voltage Noise vs. Frequency

100

CURRENT NOISE (pA/ Hz)

G = +2

10

1

100 1k 10k 100k 1M 10M 100M

10

FREQUENCY (Hz)

Figure 34. Current Noise vs. Frequency

05143-044

05143-045

3.2
VS = ±5V

3.0

2.8

V

= +5V

2.6

2.4

SUPPLY CURRENT (mA)

2.2

2.0

–40 –25 –10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

S

VS = +3V

Figure 32. Supply Current vs. Temperature for Various Supplies

05143-038

Rev. C | Page 11 of 20

80

VS = ±5V
N = 420

70

x = –260μV
σ = 780μV

60

50

40

COUNT

30

20

10

0

–4 –3 –2 –1 0 1 2 3 4

V

(mV)

OFFSET

Figure 35. Input Offset Voltage Distribution

05143-047

ADA4851-1/ADA4851-2/ADA4851-4

–30

VS = ±5V

–40

–50

–60

–70

–80

–90

–100

COMMON-MODE REJECTION (dB)

–110

–120

1k 10k 100k 1M 10M 100M 1G

FREQUENCY (Hz)

Figure 36. Common-Mode Rejection Ratio (CMRR) vs. Frequency

05143-020

0

G = +2

–10

V

= 5V

S

= 1kΩ

R

L

= 1V p-p

V

–20

IN

–30

–40

–50

–60

CROSSTALK (dB)

–70

–80

–90

–100

0.1

Figure 38. ADA4851-4, RTI Crosstalk vs. Frequency

DRIVE AMPS 1, 2, AND 4
LISTEN AMP 3

DRIVE AMP 1
LISTEN AMP 2

1 10 100

FREQUENCY (MHz)

05143-055

0

VS = ±5V

–10
–20
–30
–40
–50
–60
–70
–80
–90

POWER SUPPLY REJECTION (dB)

–100
–110

100 1k 10k 100k 1M 10M 100M 1G

+PSR

–PSR

FREQUENCY (Hz)

Figure 37. Power Supply Rejection (PSR) vs. Frequency

05143-023

CROSSTALK (dB)

–100

0

G = +2

–10

= 5V

V

S

= 1kΩ

R

L

= 1V p-p

V

–20

IN

–30

–40

–50

–60

–70

–80

–90

0.1

DRIVE AMP 1
LISTEN AMP 2

DRIVE AMP 2
LISTEN AMP 1

1 10 100

FREQUENCY (MHz)

Figure 39. ADA4851-2, RTI Crosstalk vs. Frequency

05143-060

Rev. C | Page 12 of 20

ADA4851-1/ADA4851-2/ADA4851-4

CIRCUIT DESCRIPTION

The ADA4851-1, ADA4851-2, and ADA4851-4 feature a high
slew rate input stage that is a true single-supply topology,
capable of sensing signals at or below the minus supply rail. The
rail-to-rail output stage can pull within 60 mV of either supply
rail when driving light loads and within 0.17 V when driving
150 Ω. High speed performance is maintained at supply
voltages as low as 2.7 V.

HEADROOM CONSIDERATIONS

These amplifiers are designed for use in low voltage systems.
To obtain optimum performance, it is useful to understand the
behavior of the amplifiers as input and output signals approach
the amplifiers’ headroom limits. The amplifiers’ input common­mode voltage range extends from the negative supply voltage
(actually 200 mV below this), or from ground for single-supply
operation, to within 2.2 V of the positive supply voltage.
Therefore, at a gain of 3, the amplifiers can provide full rail-to­rail output swing for supply voltages as low as 3.3 V and down
to 3 V for a gain of 4.

Exceeding the headroom limit is not a concern for any inverting
gain on any supply voltage, as long as the reference voltage at
the amplifier’s positive input lies within the amplifier’s input
common-mode range.

The input stage is the headroom limit for signals approaching
the positive rail.
input common-mode voltage for the ADA4851-1/ADA4851-2/
ADA4851-4 amplifiers on a ±5 V supply. Accurate dc
performance is maintained from approximately 200 mV below
the minus supply to within 2.2 V of the positive supply. For high
speed signals, however, there are other considerations.
shows −3 dB bandwidth vs. dc input voltage for a unity-gain
follower. As the common-mode voltage gets within 2 V of
positive supply, the amplifier responds well but the bandwidth
begins to drop as the common-mode voltage approaches the
positive supply. This can manifest itself in increased distortion
or settling time. Higher frequency signals require more
headroom than the lower frequencies to maintain distortion
performance.

Figure 40 shows a typical offset voltage vs. the

Figure 41

440

460

480

500

(μV)

520

OS

V

540

560

580

600

–6 –5 –4 –3 –2 –1 0 1 2 3 4

VCM (V)

Figure 40. V

2

G = +1
R

= 1kΩ

L

1

V

= 5V

S

0

–1

–2

GAIN (dB)

–3

–4

–5

–6

0.1 101 100

vs. Common-Mode Voltage, VS = ±5 V

OS

VCM = 3.0V

V

CM

V

CM

V

CM

FREQUENCY (MHz)

= 3.1V

= 3.2V

= 3.3V

Figure 41. Unity-Gain Follower Bandwidth vs. Input Common-Mode

1000

05143-046

05143-050

Rev. C | Page 13 of 20

ADA4851-1/ADA4851-2/ADA4851-4

Figure 42 illustrates how the rising edge settling time for the
amplifier is configured as a unity-gain follower, stretching out
as the top of a 1 V step input that approaches and exceeds the
specified input common-mode voltage limit.

For signals approaching the minus supply and inverting gain
and high positive gain configurations, the headroom limit is the
output stage. The ADA4851-1/ADA4851-2/ADA4851-4
amplifiers use a common emitter output stage. This output stage
maximizes the available output range, limited by the saturation
voltage of the output transistors. The saturation voltage
increases with the drive current that the output transistor is
required to supply due to the output transistor’s collector
resistance.

3.6
G = +1

R

= 1kΩ

3.4

L

V

= 5V

S

3.2

3.0

V

2.8

2.6

2.4

OUTPUT VOLTAGE (V)

2.2

2.0

1.8

0 102030405060708090100

Figure 42. Output Rising Edge for 1 V Step at Input Headroom Limits

As the saturation point of the output stage is approached, the
output signal shows increasing amounts of compression and
clipping. As in the input headroom case, higher frequency
signals require a bit more headroom than the lower frequency
signals.

Figure 16 illustrates this point by plotting the typical

distortion vs. the output amplitude.

OVERLOAD BEHAVIOR AND RECOVERY

Input

The specified input common-mode voltage of the ADA4851-1/
ADA4851-2/ADA4851-4 is 200 mV below the negative supply
to within 2.2 V of the positive supply. Exceeding the top limit
results in lower bandwidth and increased rise time, as seen in
Figure 41 and Figure 42. Pushing the input voltage of a unity­gain follower to less than 2 V from the positive supply leads to
the behavior shown in
output error as well as a much increased settling time. The
recovery time from input voltages 2.2 V or closer to the positive
supply is approximately 55 ns, which is limited by the settling
artifacts caused by transistors in the input stage coming out of
saturation.

= 2V TO 3V

STEP

= 2.1V TO 3.1V

V

STEP

= 2.2V TO 3.2V

V

STEP

= 2.3V TO 3.3V

V

STEP

= 2.4V TO 3.4V

V

STEP

TIME (ns)

Figure 43—an increasing amount of

05143-052

The amplifiers do not exhibit phase reversal, even for input
voltages beyond the voltage supply rails. Going more than 0.6 V
beyond the power supplies turns on protection diodes at the
input stage, which greatly increases the current draw of the
devices.

3.50
G = +1

R

= 1kΩ

L

V

= 5V

3.25

S

V

= 2.25V TO 3.25V

3.00

2.75

2.50

OUTPUT VOLTAGE (V)

2.25

2.00

0 100 200 300 400 500 600 700 800 900 1k

STEP

= 2.25V TO

V

STEP

3.5V, 4V, AND 5V

TIME (ns)

Figure 43. Pulse Response of G = 1 Follower,

Input Step Overloading the Input Stage

Output

Output overload recovery is typically within 35 ns after the
amplifier’s input is brought to a nonoverloading value.

Figure 44
shows output recovery transients for the amplifier configured in
an inverting gain of 1 recovering from a saturated output from
the top and bottom supplies to a point at midsupply.

7

6

5

4

3

INPUT
VOLTAGE
EDGES

2

1

0

INPUT AND OUTPUT VOLTAGE (V)

–1

–2

0 102030405060708090100

V

OUT

TIME (ns)

= 5V TO 2.5V

V

OUT

Figure 44. Overload Recovery

G = –1
R

= 1kΩ

L

V

= 5V

S

= 0V TO 2.5V

05143-051

05143-053

Rev. C | Page 14 of 20

ADA4851-1/ADA4851-2/ADA4851-4

SINGLE-SUPPLY VIDEO AMPLIFIER

The ADA4851 family of amplifiers is well-suited for portable
video applications. When operating in low voltage single-supply
applications, the input signal is limited by the input stage
headroom. For additional information, see the
Considerations

section. Tab l e 6 illustrates the effects of supply
voltage, input signal, various gains, and output signal swing for
the typical video amplifier shown in

R

F

+V

R

G

P

V

IN

C1

S

2.2μF

+

D

C2

0.01μF

U1

Figure 45. Video Amplifier

Figure 45.

75Ω

V′

Headroom

75Ω CABLE

75Ω

V

OUT

05143-059

Table 6. Recommended Values

Supply
Voltage
(V)

Input
Range
(V)

R

G

(kΩ)

RF
(kΩ)

Gain
(V/V)

V’
(V)

V

OUT

(V)

3 0 to 0.8 1 1 2 1.6 0.8
3 0 to 0.8 0.499 1 3 2.4 1.2
5 0 to 2.8 1 1 2 4.9 2.45

Rev. C | Page 15 of 20

ADA4851-1/ADA4851-2/ADA4851-4

OUTLINE DIMENSIONS

2.90 BSC

1.60 BSC

PIN 1

INDICATOR

1.30

1.15

0.90

0.15 MAX

4.50

4.40

4.30

1.90
BSC

0.50

0.30

45

2.80 BSC

2

0.95 BSC

1.45 MAX

SEATING
PLANE

0.22

0.08
10°

4°
0°

6

1 3

COMPLIANT TO JEDEC STANDARDS MO-178-AB

Figure 46. 6-Lead Small Outline Transistor Package [SOT-23]

(RJ-6)

Dimensions shown in millimeters

5.10

5.00

4.90

14

8

6.40
BSC

71

0.60

0.45

0.30

1.05

1.00

0.80

PIN 1

0.65
BSC

0.15

0.30

0.05

0.19

COMPLIANT TO JEDEC STANDARDS MO-153-AB-1

SEATING
PLANE

1.20
MAX

COPLANARITY

0.20

0.09

0.10

Figure 47. 14-Lead Thin Shrink Small Outline Package [TSSOP]

(RU-14)

Dimensions shown in millimeters

Rev. C | Page 16 of 20

8°
0°

0.75

0.60

0.45

ADA4851-1/ADA4851-2/ADA4851-4

0

0

3.00
BSC

8

3.00
BSC

1

PIN 1

.15
.00

0.38

0.22

COPLANARITY

0.10
COMPLIANT TO JEDEC STANDARDS MO-187-AA

0.65 BSC

5

4.90

BSC

4

SEATING
PLANE

1.10 MAX

0.23

0.08

8°
0°

0.80

0.60

0.40

Figure 48. 8-Lead Mini Small Outline Package [MSOP]

(RM-8)

Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Package Description Package Outline Branding

ADA4851-1YRJZ-R2
ADA4851-1YRJZ-RL
ADA4851-1YRJZ-RL71−40°C to +125°C 6-Lead Small Outline Transistor Package (SOT-23) RJ-6 HHB
ADA4851-2YRMZ
ADA4851-2YRMZ-RL
ADA4851-2YRMZ-RL71−40°C to +125°C 8-Lead Mini Small Outline Package (MSOP) RM-8 HSB
ADA4851-4YRUZ
ADA4851-4YRUZ-RL
ADA4851-4YRUZ-R7

1

Z = Pb-free part.

1

−40°C to +125°C 6-Lead Small Outline Transistor Package (SOT-23) RJ-6 HHB

1

−40°C to +125°C 6-Lead Small Outline Transistor Package (SOT-23) RJ-6 HHB

1

1

−40°C to +125°C 8-Lead Mini Small Outline Package (MSOP) RM-8 HSB

1

−40°C to +125°C 8-Lead Mini Small Outline Package (MSOP) RM-8 HSB

–40°C to +125°C 14-Lead Thin Shrink Small Outline Package (TSSOP) RU-14

1

–40°C to +125°C 14-Lead Thin Shrink Small Outline Package (TSSOP) RU-14

1

–40°C to +125°C 14-Lead Thin Shrink Small Outline Package (TSSOP) RU-14

Rev. C | Page 17 of 20

ADA4851-1/ADA4851-2/ADA4851-4

NOTES

Rev. C | Page 18 of 20

ADA4851-1/ADA4851-2/ADA4851-4

NOTES

Rev. C | Page 19 of 20

ADA4851-1/ADA4851-2/ADA4851-4

NOTES

©2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.

D05143–0−5/05(C)

Rev. C | Page 20 of 20