ANALOG DEVICES AD823 Service Manual

Dual, 16 MHz, Rail-to-Rail

www.BDTIC.com/ADI

FEATURES

Single-supply operation

Output swings rail-to-rail Input voltage range extends below ground Single-supply capability from 3 V to 36 V

High load drive

Capacitive load drive of 500 pF, G = +1 Output current of 15 mA, 0.5 V from supplies

Excellent ac performance on 2.6 mA/amplifier

−3 dB bandwidth of 16 MHz, G = +1 350 ns settling time to 0.01% (2 V step) Slew rate of 22 V/μs

Good dc performance

800 μV maximum input offset voltage 2 μV/°C offset voltage drift

25 pA maximum input bias current Low distortion: −108 dBc worst harmonic @ 20 kHz Low noise: 16 nV/√Hz @ 10 kHz No phase inversion with inputs to the supply rails

APPLICATIONS

Battery-powered precision instrumentation Photodiode preamps Active filters 12-bit to 16-bit data acquisition systems Medical instrumentation

GENERAL DESCRIPTION

The AD823 is a dual precision, 16 MHz, JFET input op amp that can operate from a single supply of 3.0 V to 36 V or from dual supplies of ±1.5 V to ±18 V. It has true single-supply capability with an input voltage range extending below ground in single-supply mode. Output voltage swing extends to within 50 mV of each rail for I output dynamic range.

An offset voltage of 800 µV maximum, an offset voltage drift of 2 µV/°C,

input bias currents below 25 pA, and low input voltage noise provide dc precision with source impedances up to a Gigaohm. It provides 16 MHz, −3 dB bandwidth, −108 dB THD @ 20 kHz, and a 22 V/µs slew rate with a low supply current of

2.6 mA per amplifier. The AD823 drives up to 500 pF of direct capacitive load as a follower and provides an output current of 15 mA, 0.5 V from the supply rails. This allows the amplifier to handle a wide range of load conditions.

≤ 100 µA, providing outstanding

OUT

FET Input Amplifier

AD823

CONNECTION DIAGRAM

1

OUT1

–IN1

2

3

+IN1

–V

4

S

AD823

Figure 1. 8-Lead PDIP and SOIC

3V

GND

500mV 200µs

Figure 2. Output Swing, +V

2

+VS = +5V G = +1

1

0

–1

–2

–3

–4

OUTPUT (d B)

–5

–6

–7

–8

1k

10k 100k 1M

FREQUENCY ( Hz)

Figure 3. Small Signal Bandwidth,

This combination of ac and dc performance, plus the outstanding load drive capability, results in an exceptionally versatile amplifier for applications such as A/D drivers, high speed active filters, and other low voltage, high dynamic range systems.

The AD823 is available over the industrial temperature range of

−40°C t

o +85°C and is offered in both 8-lead PDIP and 8-lead

SOIC packages.

8

+V

S

OUT2

7

–IN2

6

+IN2

5

= +3 V, G = +1

S

00901-001

G = +1

RL = 100kΩ C

= 50pF

L

+V

= +3V

S

G = +1

10M

00901-002

00901-003

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.

AD823

www.BDTIC.com/ADI

REVISION HISTORY

2/07—Rev. A to Rev. B

Updated Format..................................................................Universal

Changes to DC Performance ..........................................................5

Updated Outline Dimensions....................................................... 18

Changes to Ordering Guide ......................................................... 19

5/04—Rev. 0 to Rev. A

Changes to Specifications................................................................ 2

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

Updated Outline Dimensions....................................................... 17

5/95—Revision 0: Initial Version

Typical Performance Characteristics..............................................7

Theory of Operation ......................................................................13

Output Impedance ..................................................................... 14

Application Notes........................................................................... 15

Input Characteristics.................................................................. 15

Output Characteristics............................................................... 15

Outline Dimensions....................................................................... 18

Ordering Guide .......................................................................... 19

Rev. B | Page 2 of 20

AD823

www.BDTIC.com/ADI

SPECIFICATIONS

At TA = 25°C, +VS = +5 V, RL = 2 kΩ to 2.5 V, unless otherwise noted.

Table 1.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth, VO ≤ 0.2 V p-p G = +1 12 16 MHz Full Power Response VO = 2 V p-p 3.5 MHz Slew Rate G = −1, VO = 4 V Step 14 22 V/μs Settling Time

to 0.1% G = −1, VO = 2 V Step 320 ns to 0.01% G = −1, VO = 2 V Step 350 ns

NOISE/DISTORTION PERFORMANCE

Input Voltage Noise f = 10 kHz 16 nV/√Hz Input Current Noise f = 1 kHz 1 fA/√Hz Harmonic Distortion RL = 600 Ω to 2.5 V, VO = 2 V p-p, f = 20 kHz −108 dBc Crosstalk

f = 1 kHz RL = 5 kΩ −105 dB f = 1 MHz RL = 5 kΩ −63 dB

DC PERFORMANCE

Initial Offset 0.2 0.8 mV Maximum Offset Over temperature 0.3 2.0 mV Offset Drift 2 μV/°C Input Bias Current VCM = 0 V to 4 V 3 25 pA

at T

VCM = 0 V to 4 V 0.5 5 nA

MAX

Input Offset Current 2 20 pA

at T

0.5 nA

MAX

Open-Loop Gain VO = 0.2 V to 4 V, RL = 2 kΩ 20 45 V/mV

T

to T

MIN

INPUT CHARACTERISTICS

Input Common-Mode Voltage Range −0.2 to +3 −0.2 to +3.8 V Input Resistance 1013 Ω Input Capacitance 1.8 pF Common-Mode Rejection Ratio VCM = 0 V to 3 V 60 76 dB

OUTPUT CHARACTERISTICS

Output Voltage Swing

IL = ±100 μA 0.025 to 4.975 V IL = ±2 mA 0.08 to 4.92 V

IL = ±10 mA 0.25 to 4.75 V Output Current V Short-Circuit Current Sourcing to 2.5 V 40 mA Sinking to 2.5 V 30 mA Capacitive Load Drive G = +1 500 pF

POWER SUPPLY

Operating Range 3 36 V Quiescent Current T Power Supply Rejection Ratio VS = 5 V to 15 V, T

20 V/mV

MAX

= 0.5 V to 4.5 V 16 mA

OUT

to T

MIN

, total 5.2 5.6 mA

MAX

to T

MIN

70 80 dB

MAX

Rev. B | Page 3 of 20

AD823

www.BDTIC.com/ADI

At TA = 25°C, +VS = +3.3 V, RL = 2 kΩ to 1.65 V, unless otherwise noted.

Table 2.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth, VO ≤ 0.2 V p-p G = +1 12 15 MHz Full Power Response VO = 2 V p-p 3.2 MHz Slew Rate G = −1, VO = 2 V Step 13 20 V/μs Settling Time

to 0.1% G = −1, VO = 2 V Step 250 ns to 0.01% G = −1, VO = 2 V Step 300 ns

NOISE/DISTORTION PERFORMANCE

Input Voltage Noise f = 10 kHz 16 nV/√Hz Input Current Noise f = 1 kHz 1 fA/√Hz Harmonic Distortion RL = 100 Ω, VO = 2 V p-p, f = 20 kHz −93 dBc Crosstalk

f = 1 kHz RL = 5 kΩ −105 dB f = 1 MHz RL = 5 kΩ −63 dB

DC PERFORMANCE

Initial Offset 0.2 1.5 mV Maximum Offset Over temperature 0.5 2.5 mV Offset Drift 2 μV/°C Input Bias Current VCM = 0 V to 2 V 3 25 pA

at T

VCM = 0 V to 2 V 0.5 5 nA

MAX

Input Offset Current 2 20 pA

at T

0.5 nA

MAX

Open-Loop Gain VO = 0.2 V to 2 V, RL = 2 kΩ 15 30 V/mV

T

to T

MIN

INPUT CHARACTERISTICS

Input Common-Mode Voltage Range −0.2 to +1 −0.2 to +1.8 V Input Resistance 1013 Ω Input Capacitance 1.8 pF Common-Mode Rejection Ratio VCM = 0 V to 1 V 54 70 dB

OUTPUT CHARACTERISTICS

Output Voltage Swing

IL = ±100 μA 0.025 to 3.275 V IL = ±2 mA 0.08 to 3.22 V

IL = ±10 mA 0.25 to 3.05 V Output Current V Short-Circuit Current Sourcing to 1.5 V 40 mA Sinking to 1.5 V 30 mA Capacitive Load Drive G = +1 500 pF

POWER SUPPLY

Operating Range 3 36 V Quiescent Current T Power Supply Rejection Ratio VS = 3.3 V to 15 V, T

12 V/mV

MAX

= 0.5 V to 2.5 V 15 mA

OUT

to T

MIN

, total 5.0 5.7 mA

MAX

to T

MIN

70 80 dB

MAX

Rev. B | Page 4 of 20

AD823

www.BDTIC.com/ADI

At TA = 25°C, VS = ±15 V, RL = 2 kΩ to 0 V, unless otherwise noted.

Table 3.

Parameter Conditions Min Typ Max Unit

DYNAMIC PERFORMANCE

−3 dB Bandwidth, VO ≤ 0.2 V p-p G = +1 12 16 MHz Full Power Response VO = 2 V p-p 4 MHz Slew Rate G = −1, VO = 10 V Step 17 25 V/μs Settling Time

to 0.1% G = −1, VO = 10 V Step 550 ns to 0.01% G = −1, VO = 10 V Step 650 ns

NOISE/DISTORTION PERFORMANCE

Input Voltage Noise f = 10 kHz 16 nV/√Hz Input Current Noise f = 1 kHz 1 fA/√Hz Harmonic Distortion RL = 600 Ω, VO = 10 V p-p, f = 20 kHz −90 dBc Crosstalk

f = 1 kHz RL= 5 kΩ −105 dB f = 1 MHz RL= 5 kΩ −63 dB

DC PERFORMANCE

Initial Offset 0.7 3.5 mV Maximum Offset Over temperature 1.0 7 mV Offset Drift 2 μV/°C Input Bias Current VCM = 0 V 5 30 pA V

at T

VCM = 0 V 0.5 5 nA

MAX

Input Offset Current 2 20 pA

at T

0.5 nA

MAX

Open-Loop Gain VO = +10 V to −10 V, RL = 2 kΩ 30 60 V/mV

T

to T

MIN

INPUT CHARACTERISTICS

Input Common-Mode Voltage Range −15.2 to +13 −15.2 to +13.8 V Input Resistance 1013 Ω Input Capacitance 1.8 pF Common-Mode Rejection Ratio VCM = −15 V to +13 V 66 82 dB

OUTPUT CHARACTERISTICS

Output Voltage Swing

IL = ±100 μA −14.95 to +14.95 V IL = ±2 mA −14.92 to +14.92 V

IL = ±10 mA −14.75 to +14.75 V Output Current V Short-Circuit Current Sourcing to 0 V 80 mA Sinking to 0 V 60 mA Capacitive Load Drive G = +1 500 pF

POWER SUPPLY

Operating Range 3 36 V Quiescent Current T Power Supply Rejection Ratio VS = 5 V to 15 V, T

30 V/mV

MAX

= −10 V 60 pA

CM

= −14.5 V to +14.5 V 17 mA

OUT

to T

MIN

, total 7.0 8.4 mA

MAX

to T

MIN

70 80 dB

MAX

Rev. B | Page 5 of 20

AD823

A

www.BDTIC.com/ADI

ABSOLUTE MAXIMUM RATINGS

Table 4

Parameter Rating

Supply Voltage 36 V Internal Power Dissipation

PDIP (N) 1.3 W

SOIC (R) 0.9 W Input Voltage (Common Mode) ±VS Differential Input Voltage ±1.2 V Output Short-Circuit Duration See Figure 4 Storage Temperature Range N, R −65°C to +125°C Operating Temperature Range −40°C to +85°C Lead Temperature Range

(Soldering, 10 sec)

300°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.

2.0

8-LEAD PDIP

1.5

TION (W)

1.0

0.5

MAXIMUM POWER DISSIP

0 –50 90–40 –30 –20 –10 0 10 20 30 50 60 70 8040

Figure 4. Maximum Power Dissipation vs. Temperature

8-LEAD SOIC

AMBIENT TEMPERATURE (°C)

TJ = 150°C

THERMAL RESISTANCE

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

Specification is for device in free air.

00901-004

Table 5. Thermal Resistance

Package Type θJA Unit

8-Lead PDIP 90 °C/W 8-Lead SOIC 160 °C/W

ESD CAUTION

Rev. B | Page 6 of 20

ANALOG DEVICES AD823 Service Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

CONNECTION DIAGRAM

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

THERMAL RESISTANCE

ESD CAUTION