ANALOG DEVICES ADA4850-1 Service Manual

High Speed, Rail-to-Rail Output

www.BDTIC.com/ADI

Op Amps with Ultralow Power-Down

FEATURES

Ultralow power-down current: 150 nA/amplifier maximum
Low quiescent current: 2.4 mA/amplifier
High speed

175 MHz, −3 dB bandwidth
220 V/μs slew rate
85 ns settling time to 0.1%

Excellent video specifications

0.1 dB flatness: 14 MHz
Differential gain: 0.12%
Differential phase: 0.09°
Single-supply operation: 2.7 V to 6 V
Rail-to-rail output
Output swings to within 80 mV of either rail
Low voltage offset: 0.6 mV

APPLICATIONS

Portable multimedia players
Video cameras
Digital still cameras
Consumer video
Clock buffers

GENERAL DESCRIPTION

The ADA4850-1/ADA4850-21 are low price, high speed, voltage
feedbacks rail-to-rail output op amps with ultralow power­down. Despite their low price, the ADA4850-1/ADA4850-2
provide excellent overall performance and versatility. The
175 MHz, −3 dB bandwidth and 220 V/μs slew rate make these
amplifiers well-suited for many general-purpose, high speed
applications.

The ADA4850-1/ADA4850-2 are designed to operate at supply
voltages as low as 2.7 V and up to 6 V at 2.4 mA of supply
current per amplifier. In power-down mode, the supply current
is less than 150 nA, ideal for battery-powered applications.

The ADA4850 family provides users with a true single-supply
capability, allowing input signals to extend 200 mV below the
negative rail and to within 2.2 V of the positive rail. The output
of the amplifier can swing within 80 mV of either supply rail.

With its combination of low price, excellent differential gain
(0.12%), differential phase (0.09°), and 0.1 dB flatness out to
14 MHz, these amplifiers are ideal for video applications.

The ADA4850-1/ADA4850-2 are designed to work in the
extended temperature range of −40°C to +125°C.

ADA4850-1/ADA4850-2

PIN CONFIGURATIONS

ADA4850-1

1POWER DOWN

NC

2

–IN

3
4+IN

NC = NO CONNECT

Figure 1. 8-Lead, 3 mm × 3 mm LFCSP

NC
16

ADA4850-2

1

1V

OUT

2–IN1
3+IN1
4–V

S

5
NC

NC = NO CONNECT

Figure 2. 16-Lead, 3 mm × 3 mm LFCSP

2

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

G = +1

= 5V

V

S

–5

= 1kΩ

R

L

= 0.1V p-p

V

OUT

–6

1 10010 1000

FREQUENCY (MHz)

1

Patents pending.

Figure 3. Small Signal Frequency Response

PD2

NC

PD1

13

14

15

8

7

6

NC

NC

NC

+V

8

OUTPUT

7

NC

6

–V

5

12 +V
11 V

OUT

10 –IN2
9 +IN2

S

S

05320-106

S

2

05320-043

05320-054

Rev. B

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] ©2005–2007 Analog Devices, Inc. All rights reserved.

ADA4850-1/ADA4850-2

www.BDTIC.com/ADI

TABLE OF CONTENTS

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

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

Pin Configurations ........................................................................... 1

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

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

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

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

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

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

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

REVISION HISTORY

12/07—Rev. A to Rev. B

Changes to Applications .................................................................. 1

Updated Outline Dimensions....................................................... 14

Changes to Ordering Guide.......................................................... 14

4/05—Rev. 0 to Rev. A

Added ADA4850-1.............................................................Universal

Added 8-Lead LFCSP.........................................................Universal

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

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

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

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

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

Changes to Power-Down Pins Section and Table 5 ................... 13

Updated Outline Dimensions....................................................... 14

Changes to Ordering Guide.......................................................... 14

2/05—Revision 0: Initial Version

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

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

Circuit Description......................................................................... 12

Headroom and Overdrive Recovery Considerations............ 12

Operating the ADA4850-1/ADA4850-2 on Bipolar

Supplies........................................................................................ 13

Power-Down Pins....................................................................... 13

Outline Dimensions....................................................................... 14

Ordering Guide .......................................................................... 14

Rev. B | Page 2 of 16

ADA4850-1/ADA4850-2

www.BDTIC.com/ADI

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 160 MHz
G = +2, VO = 0.5 V p-p, RL = 150 Ω 45 MHz
Bandwidth for 0.1 dB Flatness G = +2, VO = 0.5 V p-p, RL = 150 Ω 14 MHz
Slew Rate G = +2, VO = 1 V step 110 V/μs
Settling Time to 0.1% G = +2, VO = 1 V step, RL = 150 Ω 80 ns

NOISE/DISTORTION PERFORMANCE

Harmonic Distortion (dBc) HD2/HD3 fC = 1 MHz, VO = 2 V p-p, G = +3, RL = 150 Ω −72/−77 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 0.2 %
Differential Phase G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p 0.2 Degrees

DC PERFORMANCE

Input Offset Voltage 0.6 4.1 mV
Input Offset Voltage Drift 4 μV/°C
Input Bias Current 2.4 4.4 μA
Input Bias Current Drift 4 nA/°C
Input Bias Offset Current 30 nA
Open-Loop Gain VO = 0.25 V to 0.75 V 78 100 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 to −0.5 V, G = +1 60/50 ns
Common-Mode Rejection Ratio VCM = 0.5 V −76 −108 dB

POWER-DOWN

Power-Down Input Voltage Power-down ADA4850-1/ADA4850-2 <0.7/<0.6 V
Enabled ADA4850-1/ADA4850-2 >0.8/>1.7 V
Turn-Off Time 0.7 μs
Turn-On Time 60 ns
Power-Down Bias Current/ Power Down Pin

Enabled Power-down = 3 V 37 55 μA
Power-Down Power-down = 0 V 0.01 0.2 μA

OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = +0.7 V to −0.1 V, G = +5 70/100 ns
Output Voltage Swing 0.06 to 2.83 0.03 to 2.92 V
Short-Circuit Current Sinking/sourcing 105/74 mA

POWER SUPPLY

Operating Range
Quiescent Current/Amplifier 2.4 2.8 mA
Quiescent Current (Power-Down)/Amplifier 15 150 nA
Positive Power Supply Rejection +VS = +3 V to +4 V, −VS = 0 V −83 −100 dB
Negative Power Supply Rejection +VS = +3 V, −VS = 0 V to –1 V −83 −102 dB

1

For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section.

1

2.7 6 V

Rev. B | Page 3 of 16

ADA4850-1/ADA4850-2

www.BDTIC.com/ADI

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 175 MHz
G = +1, VO = 0.5 V p-p 110 MHz
Bandwidth for 0.1 dB Flatness G = +2, VO = 1.4 V p-p, RL = 150 Ω 9 MHz
Slew Rate G = +2, VO = 4 V step 220 V/μs
G = +2, VO = 2 V step 160 V/μs
Settling Time to 0.1% G = +2, VO = 1 V step, RL = 150 Ω 85 ns

NOISE/DISTORTION PERFORMANCE

Harmonic Distortion (dBc) HD2/HD3 fC = 1 MHz, VO = 2 V p-p, G = +2, RL = 150 Ω −81/−86 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 0.12 %
Differential Phase G = +3, NTSC, RL = 150 Ω 0.09 Degrees
Crosstalk (RTI)–ADA4850-2 f = 4.5 MHz, RL = 150 Ω, VO = 2 V p-p 60 dB

DC PERFORMANCE

Input Offset Voltage 0.6 4.2 mV
Input Offset Voltage Drift 4 μV/°C
Input Bias Current 2.3 4.2 μA
Input Bias Current Drift 4 nA/°C
Input Bias Offset Current 30 nA
Open-Loop Gain VO = 2.25 V to 2.75 V 83 105 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 +2.8 V
Input Overdrive Recovery Time (Rise/Fall) VIN = +5.5 V to −0.5 V, G = +1 50/40 ns
Common-Mode Rejection Ratio VCM = 2.0 V −85 −110 dB

POWER-DOWN

Power-Down Input Voltage Power-down ADA4850-1/ADA4850-2 <0.7/<0.6 V
Enabled ADA4850-1/ADA4850-2 >0.8/>1.7 V
Turn-Off Time 0.7 μs
Turn-On Time 50 ns
Power-Down Bias Current/Power Down Pin

Enabled Power-down = 5 V 0.05 0.13 mA
Power-Down Power-down = 0 V 0.02 0.2 μA

OUTPUT CHARACTERISTICS

Output Overdrive Recovery Time (Rise/Fall) VIN = +1.1 V to −0.1 V, G = +5 60/70 ns
Output Voltage Swing 0.14 to 4.83 0.07 to 4.92 V
Short-Circuit Current Sinking/sourcing 118/94 mA

POWER SUPPLY

Operating Range
Quiescent Current/Amplifier 2.5 2.9 mA
Quiescent Current (Power-Down)/Amplifier 15 150 nA
Positive Power Supply Rejection +VS = +5 V to +6 V, −VS = 0 V −84 −100 dB
Negative Power Supply Rejection +VS = +5 V, −VS = −0 V to −1 V −84 −102 dB

1

For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section.

1

2.7 6 V

Rev. B | Page 4 of 16

ADA4850-1/ADA4850-2

(

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ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage 12.6 V
Power Dissipation See Figure 4
Power Down Pin Voltage (−VS + 6) V
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

300°C

(Soldering 10 sec)

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 the device soldered in the circuit board for
surface-mount packages.

Table 4.

Package Type θ

JA

16-Lead LFCSP 91 °C/W
8-Lead LFCSP 80 °C/W

Maximum Power Dissipation

The maximum safe power dissipation for the ADA4850-1/
ADA4850-2 is limited by the associated rise in junction
temperature (T

) on the die. At approximately 150°C, which

J

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
ADA4850-1/ADA4850-2. 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.

Unit

The power dissipated in the package (P
cent power dissipation and the power dissipated in the die due
to the ADA4850-1/ADA4850-2 drive at the output. The
quiescent power is the voltage between the supply pins (V
times the quiescent current (I

P

= Quiescent Power + (Tota l Dr i ve P o w er − Load Power)

D

⎛

()

D

⎜

IVP

SS

⎜
⎝

).

S

V

V

OUTS

×+×=

R

2

RMS output voltages should be considered. If R
to −V

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

S

V

× I

. If the rms signal levels are indeterminate, consider

S

OUT

the worst case, when V

()

D

IVP

SS

= VS/4 for RL to midsupply.

OUT

2

)

4V

/

S

+×=

R

L

In single-supply operation with R
case is V

= VS/2.

OUT

Airflow increases heat dissipation, effectively reducing θ
Also, more metal directly in contact with the package leads and
exposed paddle from metal traces through holes, ground, and
power planes reduce θ

.

JA

Figure 4 shows the maximum safe power dissipation in the

ackage vs. the ambient temperature for the LFCSP (91°C/W)

p
package on a JEDEC standard 4-layer board. θ
approximations.

2.5

2.0
LFCSP-8

LFCSP-16

1.5

1.0

0.5

MAXIMUM POWER DISSIPATION (W)

0

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

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

AMBIENT TEMPERATURE (°C)

) is the sum of the quies-

D

⎞
⎟
⎟

L

⎠

referenced to −VS, the worst

L

2

V

OUT

−

R

L

is referenced

L

values are

JA

)

S

.

JA

05320-055

Rev. B | Page 5 of 16

ESD CAUTION