High Temperature, Low Power Operational Amplifier

Data Sheet AD8634

Rev. 0 Document Feedback 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 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: 781.329.4700 ©2013 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com

FEATURES Extreme high temperature operation

−40°C to +210°C, FLATPACK package −40°C to +175°C, SOIC package

Rail-to-rail output Low power: 1.3 mA maximum Gain bandwidth product: 9.7 MHz typical at AV = 100 Low offset voltage: 250 μV maximum Unity-gain stable High slew rate: 5.0 V/μs typical at 210°C Low noise: 4.2 nV/√Hz typical at 1 kHz and 210°C

APPLICATIONS Downhole drilling and instrumentation Avionics Heavy industrial High temperature environments

GENERAL DESCRIPTION The AD8634 is a precision, 9.7 MHz bandwidth, dual amplifier that features rail-to-rail outputs. The AD8634 is guaranteed to operate from 3 V to 30 V (or from ±1.5 V to ±15 V) and at very high temperatures.

The AD8634 is well suited for applications that require both ac and dc precision performance. The combination of wide bandwidth, low noise, and precision makes the AD8634 useful in a wide variety of applications, including filters and interfacing with a variety of sensors.

PIN CONFIGURATION

OUT A 1

–IN A 2

+IN A 3

V– 4

V+8

OUT B7

–IN B6

+IN B5

AD8634TOP VIEW

(Not to Scale) 1152

4-00

1

Figure 1. SOIC and FLATPACK Pinout

This dual-channel op amp is offered in an 8-lead SOIC package with an operating temperature range of −40°C to +175°C. It is also available in an 8-lead ceramic flat package (FLATPACK) with an operating temperature range of −40°C to +210°C. Both packages are designed for robustness at extreme temperatures and are qualified for up to 1000 hours of operation at the maximum temperature rating.

The AD8634 is a member of a growing series of high temperature qualified products offered by Analog Devices, Inc. For a complete selection table of available high temperature products, see the high temperature product list and qualification data available at www.analog.com/hightemp.

AD8634 Data Sheet

Rev. 0 | Page 2 of 12

TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Pin Configuration ............................................................................. 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3

Electrical Characteristics, VSY = ±15.0 V................................... 3 Electrical Characteristics, VSY = 3.0 V ....................................... 4

Absolute Maximum Ratings ............................................................5 Predicted Lifetime vs. Operating Temperature .........................5 Thermal Resistance .......................................................................5 ESD Caution...................................................................................5

Typical Performance Characteristics ..............................................6 Applications Information .............................................................. 10

Input Protection ......................................................................... 10 Outline Dimensions ....................................................................... 11

Ordering Guide .......................................................................... 11

REVISION HISTORY 7/13—Revision 0: Initial Version

Data Sheet AD8634

Rev. 0 | Page 3 of 12

SPECIFICATIONS ELECTRICAL CHARACTERISTICS, VSY = ±15.0 V VSY = ±15.0 V, VCM = 0 V, TMIN ≤ TA ≤ TMAX, unless otherwise noted.

Table 1.

Parameter Symbol Test Conditions/ Comments

SOIC Package −40°C ≤ TA ≤ +175°C

FLATPACK Package −40°C ≤ TA ≤ +210°C

Unit Min Typ Max Min Typ Max INPUT CHARACTERISTICS

Offset Voltage VOS 250 250 μV Offset Voltage Drift ΔVOS/ΔT 0.35 0.35 μV/°C Offset Voltage Matching TA = TMAX 150 150 μV Input Bias Current IB −200 −45 +200 −200 −40 +200 nA Input Offset Current IOS 30 30 nA Input Voltage Range VIN −14.7 +14.7 −14.5 +14.5 V Common-Mode Rejection

Ratio CMRR VCM = −14.0 V to +14.0 V 105 120 100 115 dB

Large Signal Voltage Gain AVO −13.5 V ≤ VOUT ≤ +13.5 V, RL = 2 kΩ

104 112 100 108 dB

Input Impedance Differential 53||1.1 53||1.1 kΩ||pF Common-Mode 1.1||2.5 1.1||2.5 GΩ||pF

OUTPUT CHARACTERISTICS Output Voltage High VOH RL = 10 kΩ to VCM 14.8 14.90 14.8 14.90 V RL = 2 kΩ to VCM 14.0 14.5 14.0 14.5 V RL = 2 kΩ to VCM, TA = TMAX 14.60 14.75 14.60 14.75 V Output Voltage Low VOL RL = 10 kΩ to VCM −14.95 −14.8 −14.95 −14.8 V RL = 2 kΩ to VCM −14.8 −14.70 −14.75 −14.65 V RL = 2 kΩ to VCM, TA = TMAX −14.70 −14.65 V Short-Circuit Current ISC VOUT = 0 V, TA = TMAX +100/−20 +105/−18 mA

POWER SUPPLY Power Supply Rejection

Ratio PSRR VSY = ±2 V to ±18 V 105 115 103 113 dB

Supply Current per Amplifier

ISY IOUT = 0 mA, TA = TMAX 1.0 1.2 1.1 1.3 mA

DYNAMIC PERFORMANCE Slew Rate SR RL = 2 kΩ 3.6 4.9 3.6 5.0 V/µs Gain Bandwidth Product GBP VIN = 5 mV p-p, RL = 10 kΩ,

AV = 100 9.7 9.7 MHz

Unity-Gain Crossover UGC VIN = 5 mV p-p, RL = 10 kΩ, AV = 1

2.5 2.5 MHz

−3 dB Closed-Loop Bandwidth

−3dB VIN = 5 mV p-p, AV = 1 4.9 4.9 MHz

Phase Margin ΦM 84 82 Degrees NOISE PERFORMANCE

Voltage Noise en p-p 0.1 Hz to 10 Hz 0.13 0.13 µV p-p Voltage Noise Density en f = 1 kHz 4.2 4.2 nV/√Hz Current Noise Density in 0.6 0.6 pA/√Hz

AD8634 Data Sheet

Rev. 0 | Page 4 of 12

ELECTRICAL CHARACTERISTICS, VSY = 3.0 V VSY = 3.0 V, VCM = 1.5 V, VOUT = 1.5 V, TMIN ≤ TA ≤ TMAX, unless otherwise noted.

Table 2.

Parameter Symbol Test Conditions/ Comments

SOIC Package −40°C ≤ TA ≤ +175°C

FLATPACK Package −40°C ≤ TA ≤ +210°C

Unit Min Typ Max Min Typ Max INPUT CHARACTERISTICS

Offset Voltage VOS 250 250 μV Offset Voltage Drift ΔVOS/ΔT 0.35 0.35 μV/°C Offset Voltage Matching TA = TMAX 150 150 μV Input Bias Current IB −200 −45 +200 −200 −40 +200 nA Input Offset Current IOS 30 30 nA Input Voltage Range VIN 0.3 2.7 0.5 2.5 V Common-Mode Rejection

Ratio CMRR VCM = 0.3 V to 2.7 V 60 65 55 60 dB

Large Signal Voltage Gain AVO 0.5 V ≤ VOUT ≤ 2.5 V, RL = 2 kΩ

104 112 100 108 dB

Input Impedance Differential 53||1.1 53||1.1 kΩ||pF Common-Mode 2.8||2.5 2.8||2.5 GΩ||pF

OUTPUT CHARACTERISTICS Output Voltage High VOH RL = 10 kΩ to VCM 2.8 2.90 2.8 2.90 V RL = 2 kΩ to VCM 2.0 2.5 2.0 2.5 V RL = 2 kΩ to VCM, TA = TMAX 2.60 2.75 2.60 2.75 V Output Voltage Low VOL RL = 10 kΩ to VCM 50 200 50 200 mV RL = 2 kΩ to VCM 200 300 250 350 mV RL = 2 kΩ to VCM, TA = TMAX 300 350 mV Short-Circuit Current ISC VOUT = 0 V, TA = TMAX +65/−13 +70/−11 mA

POWER SUPPLY Power Supply Rejection

Ratio PSRR VSY = ±1.25 V to ±1.75 V 97 102 95 100 dB

Supply Current per Amplifier

ISY IOUT = 0 mA, TA = TMAX 0.9 1.1 1.0 1.2 mA

DYNAMIC PERFORMANCE Slew Rate SR RL = 2 kΩ 3.5 4.9 3.5 5.0 V/µs Gain Bandwidth Product GBP VIN = 5 mV p-p, RL = 10 kΩ,

AV = 100 9.7 9.7 MHz

Unity-Gain Crossover UGC VIN = 5 mV p-p, RL = 10 kΩ, AV = 1

2.5 2.5 MHz

−3 dB Closed-Loop Bandwidth

−3dB VIN = 5 mV p-p, AV = 1 4.9 4.9 MHz

Phase Margin ΦM 84 82 Degrees NOISE PERFORMANCE

Voltage Noise en p-p 0.1 Hz to 10 Hz 0.13 0.13 µV p-p Voltage Noise Density en f = 1 kHz 4.2 4.2 nV/√Hz Current Noise Density in 0.6 0.6 pA/√Hz

Data Sheet AD8634

Rev. 0 | Page 5 of 12

ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Rating Supply Voltage ±18 V Input Voltage V− ≤ VIN ≤ V+ Differential Input Voltage1 ±0.6 V Output Short-Circuit Duration to GND Indefinite Storage Temperature Range −65°C to +150°C Operating Temperature Range

SOIC Package −40°C to +175°C FLATPACK Package −40°C to +210°C

Junction Temperature SOIC Package 200°C FLATPACK Package 245°C

Lead Temperature (Soldering 60 sec) 300°C

1 For differential input voltages greater than 0.6 V, limit the input current to less than 5 mA to prevent degradation or destruction of the input devices (see the Input Protection section).

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.

PREDICTED LIFETIME vs. OPERATING TEMPERATURE Comprehensive reliability testing is performed on all Analog Devices high temperature products, including the AD8634. Product lifetimes at extended operating temperature are obtained using high temperature operating life (HTOL). Lifetimes are predicted from the Arrhenius equation, taking into account assumptions about potential design and manufacturing failure mechanisms. HTOL is performed in accordance with JEDEC JESD22-A108. A minimum of three wafer fab and assembly lots are processed through HTOL at the maximum operating temperature.

1

100k

10k

1k

100

10

120 210200190180170160150140130

PRED

ICTE

D L

IFET

IME

(Hou

rs)

OPERATING TEMPERATURE (°C) 1152

4-12

6

Figure 2. Predicted Lifetime vs. Operating Temperature

THERMAL RESISTANCE θJA is specified for the device soldered on a 4-layer JEDEC standard printed circuit board (PCB) with zero airflow.

Table 4. Thermal Resistance Package Type θJA θJC Unit 8-Lead SOIC_N 121 43 °C/W 8-Lead FLATPACK 100 15 °C/W

ESD CAUTION

AD8634 Data Sheet

Rev. 0 | Page 6 of 12

TYPICAL PERFORMANCE CHARACTERISTICS

80

70

60

50

40

30

20

10

0–100 –80 –60 –40 –20 0

VOS (µV)

NU

MB

ER O

FA

MPL

IFIE

RS

20 40 60 80 1001 1

524-

120

Figure 3. Offset Voltage Distribution, SOIC Package, VSY = ±15.0 V, TA = 175°C

25

20

15

10

5

00 0.05 0.10 0.15 0.20 0.25 0.30

TCVOS (µV/°C)

NU

MB

ER O

FA

MPL

IFIE

RS

0.35 0.40 0.45 0.50 0.55 0.60

1152

4-12

1

Figure 4. TCVOS Distribution, SOIC Package, VSY = ±15.0 V

–100

–80

–60

–40

–20

0

20

40

–100 –50 0 50 100 150 200 250

OFF

SET

VOLT

AG

E (µ

V)

TEMPERATURE (°C)

VSY = ±15VVCM = 0V

1152

4-10

4

Figure 5. Typical Offset Voltage vs. Temperature

0

10

20

30

40

50

60

–100 –95

–90

–85

–80

–75

–70

–65

–60

–55

–50

–45

–40

–35

–30

–25

–20

–15

–10 –5 0

NU

MB

ER O

FA

MPL

IFIE

RS

IB (nA) 1152

4-10

5

Figure 6. Input Bias Current Distribution, SOIC Package,

VSY = ±15.0 V, TA = 175°C

0

1

2

3

4

5

6

7

8

9

10

–2.6

–2.4

–2.2

–2.0

–1.8

–1.6

–1.4

–1.2

–1.0

–0.8

–0.6

–0.4

–0.2 0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

NU

MB

ER O

FA

MPL

IFIE

RS

IOS (nA) 1152

4-10

6

Figure 7. Input Offset Current Distribution, SOIC Package,

VSY = ±15.0 V, TA = 175°C

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

0

–100 –50 0 50 100 150 200 250

INPU

T B

IAS

CU

RR

ENT

(nA

)

TEMPERATURE (°C)

IB+IB–

1152

4-10

7

VSY = ±15VVCM = 0V

Figure 8. Typical Input Bias Current vs. Temperature

Data Sheet AD8634

Rev. 0 | Page 7 of 12

–400

–300

–200

–100

0

100

200

300

400

–16 –14 –12 –10 –8 –6 –4 –2 0 2 4 6 8 10 12 14 16

OFF

SET

VOLT

AG

E (µ

V)

COMMON-MODE VOLTAGE (V)

–40°C+25°C+210°C

1152

4-10

8

Figure 9. Offset Voltage vs. Common-Mode Voltage and Temperature,

VSY = ±15.0 V

1m

100

10

1

100m

10m

0.1 1 10 100

V OL

– V S

S (V

)

ILOAD (mA)

–40°C+175°C+210°C

1152

4-10

9

Figure 10. Negative Dropout Voltage vs. Load Current and Temperature

0

20

40

60

80

100

120

100 1k 10k 100k 1M 10M

CM

RR

(dB

)

FREQUENCY (Hz)

VSY = ±15VTA = 210°C

1152

4-11

0

Figure 11. CMRR vs. Frequency, TA = 210°C

–140

–120

–100

–80

–60

–40

–20

0

–16 –14 –12 –10 –8 –6 –4 –2 0 2 4 6 8 10 12 14 16

INPU

T B

IAS

CU

RR

ENT

(nA

)

COMMON-MODE VOLTAGE (V)

–40°C+25°C+175°C+210°C

1152

4-11

1

Figure 12. Input Bias Current vs. Common-Mode Voltage and Temperature,

VSY = ±15.0 V

10m

100m

1

10

100

1 10 100 1000

V OH

– V

DD

(V)

ILOAD (mA)

–40°C+25°C+210°C

1152

4-11

2

Figure 13. Positive Dropout Voltage vs. Load Current and Temperature

–20

0

20

40

60

80

100

120

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

PSR

R (d

B)

FREQUENCY (Hz)

+PSRR–PSRR

1152

4-01

8

VSY = ±15VTA = 210°C

Figure 14. PSRR vs. Frequency

AD8634 Data Sheet

Rev. 0 | Page 8 of 12

–90

–45

0

45

90

135

180

–40

–20

0

20

40

60

80

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

PHA

SE M

AR

GIN

(Deg

rees

)11

524-

114

GA

IN (d

B)

FREQUENCY (Hz)

GAINPHASE MARGIN

VSY = ±15VRL = 10kΩ

Figure 15. Gain and Phase Margin vs. Frequency, TA = 210°C

CH1 500mV CH2 500mV A CH1 0V

Δ: 1.85V@: 920mVΔ: 320ns@: 140ns

CH1 AMPL2.93V

1152

4-02

1

INPUT

OUTPUT

Figure 16. Large Signal Positive Edge Response, VSY = ±15.0 V,

TA = 175°C

CH1 500mV CH2 500mV A CH1 0V

Δ: 1.69V@: –750mVΔ: 320ns@: 140ns

CH1 AMPL2.92V

1152

4-02

3

INPUT

OUTPUT

Figure 17. Large Signal Negative Edge Response, VSY = ±15.0 V,

TA = 175°C

0

500

1000

1500

2000

2500

0 5 10 15 20 25 30 35

SUPP

LY C

UR

REN

T (µ

A)

SUPPLY VOLTAGE (V)

–40°C+25°C+175°C+210°C

1152

4-11

7

Figure 18. Supply Current vs. Supply Voltage and Temperature

CH1 500mV CH2 500mV A CH1 0V

Δ: 1.61V@: –710mVΔ: 280ns@: –140ns

CH1 AMPL2.91V

1152

4-02

0

INPUT

OUTPUT

Figure 19. Large Signal Positive Edge Response, VSY = ±15.0 V,

TA = 210°C

CH1 500mV CH2 500mV A CH1 0V

Δ: 1.67V@: 830mVΔ: 280ns@: –140ns

CH1 AMPL2.91V

1152

4-02

2

INPUT

OUTPUT

Figure 20. Large Signal Negative Edge Response, VSY = ±15.0 V,

TA = 210°C

Data Sheet AD8634

Rev. 0 | Page 9 of 12

1

10

100

1000

10 100 1k 10k

VOLT

AG

E N

OIS

E D

ENSI

TY (n

V/√H

z)

FREQUENCY (Hz)

+25°C+210°C

1152

4-12

5

VSY = ±15V

Figure 21. Voltage Noise Density vs. Frequency

AD8634 Data Sheet

Rev. 0 | Page 10 of 12

APPLICATIONS INFORMATION Figure 23 illustrates a typical application circuit that uses the AD8634 and other Analog Devices high temperature products.

INPUT PROTECTION As with any semiconductor device, if the input voltages applied to the AD8634 exceed either supply voltage, the input overvoltage I-to-V characteristic of the device must be considered. When an overvoltage condition occurs, the amplifier can be damaged, depending on the magnitude of the applied voltage and the magnitude of the fault current.

The protection diodes between the input and supply pins conduct when the input common-mode voltage exceeds either supply pin by a diode drop. This diode drop varies with temperature and is in the range of 0.3 V to 0.8 V. The AD8634 has no internal current-limiting resistors; therefore, fault currents can quickly rise to damaging levels.

This input current is not inherently damaging to the device, provided that it is limited to 5 mA or less. If a fault condition causes more than 5 mA to flow, an external series resistor should be added at the expense of additional thermal noise.

Figure 22 illustrates a typical noninverting configuration for an overvoltage-protected amplifier where the series resistance, RS, is chosen such that

RS = (VIN (MAX) − VSUPPLY)/5 mA

RS

R2

VIN

VOUT1/2

AD8634

1152

4-07

5

Figure 22. Resistance in Series with Inputs

Limits Overvoltage Currents to Safe Values

For example, a 1 kΩ resistor protects the AD8634 against input signals up to 5 V above and below the supplies. Note that the thermal noise of a 1 kΩ resistor at room temperature is 4 nV/√Hz, which is close to the voltage noise of the AD8634.

For configurations where both inputs are used, add a series resistor at each input to protect the inputs against damage. To ensure optimum dc and ac performance, it is recommended that source impedance levels be balanced.

1152

4-07

6

U2AAD8634

U1ADR225VS

GND

OUTPUT

R12.5kΩ

C110µF

C20.1µF C3

1µFC40.1µF

SIGNAL OUT

R22.5kΩ

R32.5kΩ

VCC+5V

VCC

+5V

VCC

+5V

VEE–5V

VEE

–5V

RTD

U3AD8229

++

Figure 23. Typical High Temperature RTD Signal Conditioning Circuit

Data Sheet AD8634

Rev. 0 | Page 11 of 12

OUTLINE DIMENSIONS

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FORREFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

COMPLIANT TO JEDEC STANDARDS MS-012-AA

0124

07-A

0.25 (0.0098)0.17 (0.0067)

1.27 (0.0500)0.40 (0.0157)

0.50 (0.0196)0.25 (0.0099) 45°

8°0°

1.75 (0.0688)1.35 (0.0532)

SEATINGPLANE

0.25 (0.0098)0.10 (0.0040)

41

8 5

5.00 (0.1968)4.80 (0.1890)

4.00 (0.1574)3.80 (0.1497)

1.27 (0.0500)BSC

6.20 (0.2441)5.80 (0.2284)

0.51 (0.0201)0.31 (0.0122)

COPLANARITY0.10

Figure 24. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body (R-8)

Dimensions shown in millimeters and (inches)

03-2

6-20

13-A

0.2600.255 SQ0.250

1.00

TOP VIEW BOTTOM VIEW

END VIEW

SIDE VIEW

0.012 RTYP

0.1750.026 MIN

0.1950.190 SQ0.185

0.1550.1500.145

0.0530.0500.047

0.0060.0050.004

0.0910.0830.075

0.0190.0170.015

1

4

8

5

IDEXMARK

0.0540.0440.034

0.05 TYP

0.024

0.007MIN

0.035TYP

Figure 25. 8-Lead Ceramic Flat Package [FLATPACK]

(F-8-2) Dimensions shown in inches

ORDERING GUIDE Model1, 2 Temperature Range Package Description Package Option AD8634HRZN −40°C to +175°C 8-Lead Standard Small Outline Package [SOIC_N] R-8 AD8634HFZ −40°C to +210°C 8-Lead Ceramic Flat Package [FLATPACK] F-8-2 1 Z = RoHS Compliant Part. 2 The FLATPACK is prerelease only.

AD8634 Data Sheet

Rev. 0 | Page 12 of 12

NOTES

©2013 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D11524-0-7/13(0)