Analog Devices AD797BR-REEL7, AD797BR-REEL, AD797BR, AD797BN, AD797AR-REEL7 Datasheet

a	Ultralow Distortion,
	Ultralow Noise Op Amp

FEATURES

Low Noise

0.9 nV/ÖHz typ (1.2 nV/ÖHz max) Input Voltage

Noise at 1 kHz

50 nV p-p Input Voltage Noise, 0.1 Hz to 10 Hz Low Distortion

–120 dB Total Harmonic Distortion at 20 kHz Excellent AC Characteristics

800 ns Settling Time to 16 Bits (10 V Step) 110 MHz Gain Bandwidth (G = 1000)

8 MHz Bandwidth (G = 10)

280 kHz Full Power Bandwidth at 20 V p-p 20 V/ms Slew Rate

Excellent DC Precision

80 mV max Input Offset Voltage

1.0 mV/8C VOS Drift

Specified for 65 V and 615 V Power Supplies

High Output Drive Current of 50 mA

APPLICATIONS

Professional Audio Preamplifiers

IR, CCD, and Sonar Imaging Systems

Spectrum Analyzers

Ultrasound Preamplifiers

Seismic Detectors

SD ADC/DAC Buffers

PRODUCT DESCRIPTION

The AD797 is a very low noise, low distortion operational amplifier ideal for use as a preamplifier. The low noise of 0.9 nV/ÖHz and low total harmonic distortion of –120 dB at audio bandwidths give the AD797 the wide dynamic range

	5
Hz	4
– nV/
NOISE	3
VOLTAGE	2
INPUT	1
	0

10

100

1k

10k

100k

1M

10M

FREQUENCY – Hz

AD797 Voltage Noise Spectral Density

*Patent pending.

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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

AD797*

CONNECTION DIAGRAM

8-Pin Plastic Mini-DIP (N),

Cerdip (Q) and SOIC (R) Packages

					DECOMPENSATION &
					DISTORTION
OFFSET NULL	1			8
			AD797		NEUTRALIZATION
–IN	2			7	+VS
+IN	3			6	OUTPUT
–VS	4		TOP VIEW	5	OFFSET NULL

necessary for preamps in microphones and mixing consoles. Furthermore, the AD797’s excellent slew rate of 20 V/ms and 110 MHz gain bandwidth make it highly suitable for low frequency ultrasound applications.

The AD797 is also useful in IR and Sonar Imaging applications where the widest dynamic range is necessary. The low distortion and 16-bit settling time of the AD797 make it ideal for buffering the inputs to SD ADCs or the outputs of high resolution DACs especially when they are used in critical applications such as seismic detection and spectrum analyzers. Key features such as a 50 mA output current drive and the specified power supply voltage range of ±5 to ±15 volts make the AD797 an excellent general purpose amplifier.

–90

–100 0.001

THD– dB								0.0003		THD– %
–110
–120								0.0001
						MEASUREMENT
						LIMIT
–130
100		300	1k	3k	10k	30k	100k	300k
				FREQUENCY – Hz

THD vs. Frequency

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: [phone] Fax: [phone]

AD797–SPECIFICATIONS (@ TA = +258C and VS = 615 V dc, unless otherwise noted)

AD797A/S1

AD797B

Model

Conditions

VS

Min

Typ

Max

Min

Typ

Max

Units

INPUT OFFSET VOLTAGE

±5 V, ± 15 V

25

80

10

40

mV

TMIN to TMAX

50

125/180

30

60

mV

Offset Voltage Drift

±5 V, ± 15 V

0.2

1.0

0.2

0.6

mV/°C

INPUT BIAS CURRENT

±5 V, ± 15 V

0.25

1.5

0.25

0.9

mA

TMIN to TMAX

0.5

3.0

0.25

2.0

mA

INPUT OFFSET CURRENT

±5 V, ± 15 V

100

400

80

200

nA

TMIN to TMAX

120

600/700

120

300

nA

OPEN-LOOP GAIN

VOUT = ± 10 V

±15 V

RLOAD = 2 kW

1

20

2

20

V/mV

TMIN to TMAX

1

6

2

10

V/mV

RLOAD = 600 W

1

15

2

15

V/mV

TMIN to TMAX

1

5

2

7

V/mV

@ 20 kHz2

14000

20000

14000

20000

V/V

DYNAMIC PERFORMANCE

Gain Bandwidth Product

G = 1000

±15 V

110

110

MHz

G = 10002

±15 V

450

450

MHz

–3 dB Bandwidth

G = 10

±15 V

8

8

MHz

Full Power Bandwidth3

VO = 20 V p-p,

RLOAD = 1 kW

±15 V

280

280

kHz

Slew Rate

RLOAD = 1 kW

±15 V

12.5

20

12.5

20

V/ms

Settling Time to 0.0015%

10 V Step

±15 V

800

1200

800

1200

ns

COMMON-MODE REJECTION

VCM = CMVR

±5 V, ± 15 V

114

130

120

130

dB

TMIN to TMAX

110

120

114

120

dB

POWER SUPPLY REJECTION

VS = ±5 V to ± 18 V

114

130

120

130

dB

TMIN to TMAX

110

120

114

120

dB

INPUT VOLTAGE NOISE

f = 0. 1 Hz to 10 Hz

±15 V

50

50

nV p-p

f = 10 Hz

±15 V

1.7

1.7

2.5

nV/Ö

Hz

f = 1 kHz

±15 V

0.9

1.2

0.9

1.2

nV/Ö

Hz

f = 10 Hz–1 MHz

±15 V

1.0

1.3

1.0

1.2

mV rms

INPUT CURRENT NOISE

f = 1 kHz

±15 V

2.0

2.0

pA/Ö

Hz

INPUT COMMON-MODE

±15 V

±11

±12

±11

±12

V

VOLTAGE RANGE

±5 V

±2.5

±3

±2.5

±3

V

OUTPUT VOLTAGE SWING

RLOAD = 2 kW

±15 V

±12

±13

±12

±13

V

RLOAD = 600 W

±15 V

±11

±13

±11

±13

V

RLOAD = 600 W

±5 V

±2.5

±3

±2.5

±3

V

Short-Circuit Current

±5 V, ± 15 V

80

80

mA

Output Current4

±5 V, ± 15 V

30

50

30

50

mA

TOTAL HARMONIC DISTORTION

RLOAD = 1 kW, CN = 50 pF

±15 V

–98

–90

–98

–90

dB

f = 250 kHz, 3 V rms

RLOAD = 1 kW

±15 V

–120

–110

–120

–110

dB

f = 20 kHz, 3 V rms

INPUT CHARACTERISTICS

Input Resistance (Differential)

7.5

7.5

kW

Input Resistance (Common Mode)

100

100

MW

Input Capacitance (Differential)5

20

20

pF

Input Capacitance (Common Mode)

5

5

pF

OUTPUT RESISTANCE

AV = +1, f = 1 kHz

3

3

mW

POWER SUPPLY

Operating Range

±5 V, ± 15 V

±5

±18

±5

±18

V

Quiescent Current

8.2

10.5

8.2

10.5

mA

NOTES

1See standard military drawing for 883B specifications.

2Specified using external decompensation capacitor, see Applications section.

3Full Power Bandwidth = Slew Rate/2 π VPEAK. 4Output Current for |VS – VOUT| >4 V, AOL > 200 kΩ.

5Differential input capacitance consists of 1.5 pF package capacitance and 18.5 pF from the input differential pair.

Specifications subject to change without notice.

–2–

REV. C

AD797

ABSOLUTE MAXIMUM RATINGS1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V Internal Power Dissipation @ +25°C2

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±VS Differential Input Voltage3 . . . . . . . . . . . . . . . . . . . . . . ±0.7 V

Output Short Circuit Duration . . . . . . .Indefinite Within max Internal Power Dissipation Storage Temperature Range (Cerdip) . . . . . . –65°C to +150°C

Storage Temperature Range (N, R Suffix) . . –65°C to +125°C Operating Temperature Range

AD797A/B . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C AD797S . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C Lead Temperature Range (Soldering 60 sec) . . . . . . . +300°C

NOTES

1Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only, and 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.

2Internal Power Dissipation:

8-Pin SOIC = 0.9 Watts (TA–25°C)/θJA

8-Pin Plastic DIP and Cerdip = 1.3 Watts – (TA–25°C)/θJA Thermal Characteristics

8-Pin Plastic DIP Package: θJA = 95°C/W 8-Pin Cerdip Package: θJA = 110°C/W

8-Pin Small Outline Package: θJA = 155°C/W

3The AD797’s inputs are protected by back-to-back diodes. To achieve low noise, internal current limiting resistors are not incorporated into the design of this amplifier. If the differential input voltage exceeds ± 0.7 V, the input current should be limited to less than 25 mA by series protection resistors. Note, however, that this will degrade the low noise performance of the device.

ESD SUSCEPTIBILITY

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 volts, which readily accumulate on the human body and on test equipment, can discharge without detection. Although the AD797 features proprietary ESD protection circuitry, permanent damage may still occur on these devices if they are subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid any performance degradation or loss of functionality.

ORDERING GUIDE

	Temperature	Package	Package
Model	Range	Description	Option
AD797AN	–40°C to +85°C	8-Pin Plastic DIP	N-8
AD797BN	–40°C to +85°C	8-Pin Plastic DIP	N-8
AD797BR	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
AD797BR-REEL	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
AD797BR-REEL7	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
AD797AR	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
AD797AR-REEL	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
AD797AR-REEL7	–40°C to +85°C	8-Pin Plastic SOIC	SO-8
5962-9313301MPA	–55°C to +125°C	8-Pin Cerdip	Q-8

METALIZATION PHOTO

Contact factory for latest dimensions.

Dimensions shown in inches and (mm).

NOTE

The AD797 has double layer metal. Only one layer is shown here for clarity.

REV. C

–3–

AD797–Typical Characteristics

±Volts–	20
	15
RANGE
MODE-COMMON	10
INPUT	5
	0
			5	10	15	20
	0

SUPPLY VOLTAGE – ±Volts

Figure 1. Common-Mode Voltage Range vs. Supply

±Volts	20
	15
–SWING
				–VOUT
VOLTAGE	10
OUTPUT					+VOUT
	5
	0
				5	10	15	20
	0
				SUPPLY VOLTAGE – ±Volts
	Figure 2. Output Voltage Swing vs. Supply
p-p	30
					VS = ±15V
Volts–
	20
SWINGVOLTAGE
	10
OUTPUT					VS = ±5V
	0
	10			100	1k		10k

LOAD RESISTANCE – Ω

Figure 3. Output Voltage Swing vs. Load Resistance

0.01 V/DIV

VERTICAL SCALE –

HORIZONTAL SCALE – 5 sec/DIV

Figure 4. 0.1 Hz to 10 Hz Noise

0.0

A	–0.5
CURRENT –	–1.0
INPUT BIAS	–1.5
	–2.0

	–60		–40	–20	0	20	40	60		80	100	120		140
						TEMPERATURE – °C
	Figure 5. Input Bias Current vs. Temperature
mA–	140
	120
CURRENT	100							SOURCE CURRENT
CIRCUITSHORT	60		SINK CURRENT
	80
	40
	–60		–40	–20	0	20	40	60		80	100	120		140
						TEMPERATURE – °C

Figure 6. Short Circuit Current vs. Temperature

–4–

REV. C

mA–	11
	10		+125°C
CURRENT	9
SUPPLY	8		+25°C
QUIESCENT	7
			–55°C
	6
	0	5	10	15	20

SUPPLY VOLTAGE – ±Volts

Figure 7. Quiescent Supply Current vs. Supply Voltage

	12		FREQ = 1kHz
rms			RL = 600W
	9		G = +10
Volts–
VOLTAGE	6
OUTPUT	3
	0
	0		±5	±10	±15	±20

SUPPLY VOLTAGE – Volts

Figure 8. Output Voltage vs. Supply for 0.01% Distortion

	1.0
	0.8
s				0.0015%
–	0.6
TIME
SETTLING					0.01%
	0.4
	0.2
	0.0
	0	2	4	6	8	10
			STEP SIZE – Volts

Figure 9. Settling Time vs. Step Size (±)

							AD797
dB–	140
	120					PSR
REJECTIONSUPPLYPOWER						+SUPPLY				dB–REJECTIONMODECOMMON
	100			PSR					150
				–SUPPLY
	80								125
						CMR
	60								100
	40								75
	20								50
	1		10	100	1k	10k	100k	1M

FREQUENCY – Hz

Figure 10. Power Supply and Common-Mode Rejection vs. Frequency

	–60		RL = 600 W
			G = +10
			FREQ = 10kHz
NOISEdB–			NOISE BW = 100kHz
	–80
+			V	= ±5V
			S
THD	–100
					VS = ±15V
	–120
	0.01		0.1	1.0	10

OUTPUT LEVEL – Volts

Figure 11. Total Harmonic Distortion (THD) + Noise vs. Output Level

30

±15V SUPPLIES

RL = 600 Ω

20

10
	±5V SUPPLIES
0
10k	100k	1M	10M

Figure 12. Large Signal Frequency Response

REV. C

–5–