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

V

查询ADA4850-2供应商

High Speed, Rail-to-Rail Output,

FEATURES

Ultralow power-down current: 150 nA/amp max
Low quiescent current: 2.4 mA/amp
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

Op Amp with Ultralow Power-Down

ADA4850-1/ADA4850-2

PIN CONFIGURATIONS

ADA4850-1

1POWER DOWN
2NC

–IN

3
4+IN

NC = NO CONNECT

Figure 1. 8-Lead, 3 mm × 3 mm LFCSP

2

1

C

C

D

D

N
6

1

P

N

P

3

4

5

1

1

1

ADA4850-2

1

1

OUT

2–IN1
3+IN1
4–V

S

8

7

5

6
C

C
N

NC = NO CONNECT

C

C

N

N

N

Figure 2. 16-Lead, 3 mm × 3 mm LFCSPP

+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

GENERAL DESCRIPTION

The ADA4850-1, ADA4850-21 are low price, high speed,
voltage feedback rail-to-rail output op amps with ultralow
power-down. 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 general­purpose, 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 (0.09º), and 0.1 dB flatness out to
14 MHz, these amplifiers are ideal for video applications.

Rev. A

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

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

Patent pending.

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

Figure 3. Small Signal Freq uency Respons e

www.analog.com

05320-054

ADA4850-1/ADA4850-2

TABLE OF CONTENTS

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

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

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

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

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

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

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

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

REVISION HISTORY

4/05—Rev. 0 to Rev. A

AddedADA4850-1..............................................................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

Operating the ADA4850-1/ADA4850-2 on
Bipolar Supplies

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

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

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

.......................................................................... 13

2/05—Revision 0: Initial Version

Rev. A | Page 2 of 16

ADA4850-1/ADA4850-2

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
Input Current Noise f = 100 kHz 2.5

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

Input Bias Current 2.4 4.4 µA
Input Bias Current Drift 4

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

1

2.7 6 V
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 section. Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies

nV/√Hz
pA/√Hz

µV/°C

nA/°C

Rev. A | Page 3 of 16

ADA4850-1/ADA4850-2

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
Input Current Noise f = 100 kHz 2.5

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

Input Bias Current 2.3 4.2 µA
Input Bias Current Drift 4

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

1

2.7 6 V
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 section. Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies

nV/√Hz
pA/√Hz

µV/°C

nA/°C

Rev. A | Page 4 of 16

ADA4850-1/ADA4850-2

(

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.

The power dissipated in the package (P
quiescent 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

= Quiescent Power + (Total D riv e P o w er − Load Power)

P

D

⎛

V

()

D

⎜

IVP

SS

⎜

2

⎝

).

S

⎞

V

OUTS

⎟

×+×=

⎟

R

L

⎠

RMS output voltages should be considered. If R

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

to −V

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

) is the sum of the

D

)

S

2

V

OUT

–

R

L

is referenced

L

referenced to −VS, the worst

L

THERMAL RESISTANCE

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

Table 4. Thermal Resistance

Package Type θ

JA

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

Unit

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
package vs. the ambient temperature for the LFCSP (91°C/W)
package on a JEDEC standard 4-layer board. θ
approximations.

2.5

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 is

J

the glass transition temperature, the plastic changes its

2.0

1.5

LFCSP-8

LFCSP-16

properties. Even temporarily exceeding this temperature limit
may change the stresses that the package exerts on the die,

1.0

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

0.5

MAXIMUM POWER DISSIPATION (W)

silicon devices, potentially causing degradation or loss of
functionality.

0

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

AMBIENT TEMPERATURE (°C)

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

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.

values are

JA

.

JA

05320-055

Rev. A | Page 5 of 16

ADA4850-1/ADA4850-2

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

–5

NORMALIZED CLOSED-LOOP GAIN (dB)

–6

1 10 100

G = +10

FREQUENCY (MHz)

G = +2

VS = 5V
R

= 150Ω

L

V

OUT

= 0.1V p-p

Figure 5. Small Signal Frequency Response for Various Gains

2

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

VS = 5V
G = +1

–5

V

= 0.1V p-p

OUT

–6

1 10010 1000

RL = 1kΩ

FREQUENCY (MHz)

RL = 150Ω

Figure 6. Small Signal Frequency Response for Various Loads

3

2

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

G = +1
R

= 150Ω

–5

L

= 0.1V p-p

V

OUT

–6

1 10010 1000

FREQUENCY (MHz)

VS = 5V

= 3V

V

S

Figure 7. Small Signal Frequency Response for Various Supplies

G = –1

05320-044

05320-045

05320-046

4

G = +1

= 5V

V

3

S

= 1kΩ

R

L

V

2

OUT

1

0

–1

–2

–3

CLOSED-LOOP GAIN (dB)

–4

–5

–6

1 10010 300

Figure 8. Small Signal Frequency Response for Various Capacitor Loads

6.2

6.1

6.0

5.9
V

5.8

GAIN (dB)

5.7

5.6

5.5

5.4

100k 100M

1

0

–1

–2

–3

–4

CLOSED-LOOP GAIN (dB)

–5

–6

–7

1 10010 1000

Figure 10. Large Frequency Response for Various Loads

= 0.1V p-p

FREQUENCY (MHz)

= 5V, V

S

VS = 5V, V

OUT

VS = 3V, V

= 2V p-p

= 1.4V p-p

OUT

= 0.5V p-p

OUT

VS = 5V, V

1M 10M

= 0.1V p-p

OUT

FREQUENCY (Hz)

Figure 9. 0.1 dB Flatness Response

R

= 150Ω

L

= 1kΩ

R

L

FREQUENCY (MHz)

0pF

1pF

VS = 5V
G = +2
R

VS = 5V
G = +1
V

OUT

6pF

= 150Ω

L

= 0.5V p-p

05320-007

05320-047

05320-048

Rev. A | Page 6 of 16