Analog Devices AD8667 Service Manual

16 V, 250 μA, Dual Precision, CMOS,

FEATURES

Lower power at high voltage: 180 μA typical Low offset voltage: 100 μV Voltage noise

21 nV/√Hz at 10 kHz

23 nV/√Hz at 1 kHz Low input bias current: 300 fA Single-supply operation: 5 V to 16 V Dual-supply operation: ±2.5 V to ±8 V Output drive: 10 mA Unity gain stable

APPLICATIONS

Medical equipment Physiological measurement Precision references Buffer/level shifting Portable operated systems High density power budget systems Multipole filters Sensors Photodiode amplification ADC drivers

Rail-to-Rail Output Operational Amplifier

AD8667

PIN CONFIGURATION

OUT A

1

AD8667

2

–IN A

+IN A

Figure 1. 8-Lead MSOP, 8-Lead SOIC

V–

TOP VIEW

3

(Not to Scale)

4

8

7

6

5

V+

OUT B

–IN B

+IN B

06276-001

GENERAL DESCRIPTION

The AD8667 is a dual, rail-to-rail output, single-supply/dual-supply amplifier that uses Analog Devices, Inc. patented DigiTrim® trimming technique to achieve low offset voltage, 300 μV over the common-mode range. The AD8667 features an extended operating range with supply voltages up to 16 V for low power operation with an I The device is designed for low noise at higher voltages: 21 nV/√Hz at 10 kHz and 23 nV/√Hz at 1 kHz. It also features a low input bias current of 300 fA and a 10 mA output drive.

The combination of low supply currents, low offsets, very low input bias currents, and wide supply range makes the AD8667

Rev. 0

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.

of <325 μA per amplifier over temperature.

SY

ideal for a wide variety of low power applications. Systems utilizing dc-to-low frequency measurements or high impedance sensors, such as photodiodes, benefit from the low input bias current, low noise, low offset, and low drive current. The wide operating voltage range matches today’s high performance ADCs and DACs. Medical monitoring equipment can take advantage of the low voltage noise, high input impedance, low voltage, and low current noise.

The AD8667 is specified over the extended industrial temperature range of −40°C to +125°C.

AD8667

REVISION HISTORY

5/07—Revision 0: Initial Version

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

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

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

Outline Dimensions....................................................................... 13

Ordering Guide .......................................................................... 13

Rev. 0 | Page 2 of 16

AD8667

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

VS = 5.0 V, VCM = VS/2, TA = 25°C unless otherwise noted.

Table 1.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS V

−40°C < TA < +125°C 350 μV V

−40°C < TA < +85°C 100 450 μV V Input Bias Current IB 0.3 pA

−40°C < TA < +85°C 20 pA

−40°C < TA < +125°C 150 pA Input Offset Current IOS 0.2 pA

−40°C < TA < +85°C 15 pA

−40°C < TA < +125°C 50 pA Input Voltage Range IVR −40°C < TA < +85°C 0 3.5 V

−40°C < TA < +125°C 0.2 3.5 V Common-Mode Rejection Ratio CMRR VCM = 0 V to 3.5 V 80 90 dB V Large Signal Voltage Gain AVO R Offset Voltage Drift ΔVOS/ΔT −40°C < TA < +125°C 1.3 5 μV/°C

OUTPUT CHARACTERISTICS

Output Voltage High VOH I

−40°C < TA < +125°C 4.6 4.7 V Output Voltage Low VOL I

−40°C < TA < +125°C 200 250 mV Short-Circuit Current ISC ±6 mA Closed-Loop Output Impedance Z

f = 100 kHz, AV = 1 120 Ω

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = 5 V to 16 V 95 105 dB Supply Current/Amplifier ISY 180 275 μA

−40°C < TA < +125°C 325 μA DYNAMIC PERFORMANCE

Slew Rate SR RL = 2 kΩ 0.2 V/μs Settling Time tS To 0.1%, 0 V to 2 V step, AV = 10 12 μs Gain Bandwidth Product GBP 600 kHz Phase Margin ΦM 60 Degrees

NOISE PERFORMANCE

Peak-to-Peak Noise e

f = 0.1 Hz to 10 Hz 3 μV p-p

n p-p

Voltage Noise Density en f = 10 kHz 21 nV/√Hz f = 1 kHz 23 nV/√Hz Current Noise Density in f = 1 kHz 0.05 pA/√Hz

= 2.5 V 100 μV

CM

= 0 V to 3.5 V 70 300 μV

CM

= 0.2 V to 3.5 V, −40°C < TA < +125°C 100 450 μV

CM

= 0.2 V to 3.5 V, −40°C < TA < +125°C 80 90 dB

CM

= 2 kΩ, VO = 0.5 V to 4.5 V 106 115 dB

L

= 1 mA 4.65 4.8 V

L

= 1 mA 150 200 mV

L

Rev. 0 | Page 3 of 16

AD8667

VS = 16 V, VCM = VS/2, TA = 25°C unless otherwise noted.

Table 2.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS V

−40°C < TA < +125°C 350 μV V

−40°C < TA < +85°C 450 μV V Input Bias Current IB 0.3 pA

−40°C < TA < +85°C 30 pA

−40°C < TA < +125°C 250 pA Input Offset Current IOS 0.2 pA

−40°C < TA < +85°C 25 pA

−40°C < TA < +125°C 150 pA Input Voltage Range IVR −40°C < TA < +85°C 0 14.5 V

−40°C < TA < +125°C 0.2 14.5 V Common-Mode Rejection Ratio CMRR VCM = 0 V to 14.5 V 90 100 dB V Large Signal Voltage Gain AVO R Offset Voltage Drift ΔVOS/ΔT 1.2 5 μV/°C

OUTPUT CHARACTERISTICS

Output Voltage High VOH I I I Output Voltage Low VOL I I I Short-Circuit Current ISC ±50 mA Closed-Loop Output Impedance Z

f = 100 kHz, AV = 1 100 Ω

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = 5 V to 16 V, −40°C < TA < +125°C 95 105 dB Supply Current/Amplifier ISY 230 285 μA

−40°C < TA < +125°C 325 μA DYNAMIC PERFORMANCE

Slew Rate SR RL = 2 kΩ 0.3 V/μs Settling Time tS To 0.1%, 0 V to 2 V step 12 μs Gain Bandwidth Product GBP 600 kHz Phase Margin ΦM 60 Degrees

NOISE PERFORMANCE

Peak-to-Peak Noise e

f = 0.1 Hz to 10 Hz 3 μV p-p

n p-p

Voltage Noise Density en f = 1 kHz 23 nV/√Hz f = 10 kHz 21 nV/√Hz Current Noise Density in f = 1 kHz 0.05 pA/√Hz

= 8 V 40 300 μV

CM

= 0 V to 14.5 V 70 300 μV

CM

= 0.2 V to 14.5 V, −40°C < TA < +125°C 450 μV

CM

= 0.2 V to 14.5 V, −40°C < TA < +125°C 90 100 dB

CM

= 2 kΩ, VO = 0.5 V to 15.5 V 112 124 dB

L

= 1 mA 15.8 15.9 V

L

= 10 mA 14.8 15.1 V

L

= 10 mA, −40°C < TA < +125°C 14.65 14.8 V

L

= 1 mA 80 100 mV

L

= 10 mA 600 720 mV

L

= 10 mA, −40°C < TA < +125°C 800 900 mV

L

Rev. 0 | Page 4 of 16

AD8667

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage 18 V Input Voltage −0.1 V to VS Differential Input Voltage 18 V Output Short-Circuit Duration to GND Indefinite Storage Temperature Range −60°C to +150°C Lead Temperature (Soldering, 60 sec) 300°C Operating Temperature Range −40°C to +125°C Junction Temperature Range −65°C to +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, a device soldered in a circuit board for surface-mount packages.

Table 4. Thermal Resistance

Package Type θJA θ

8-Lead MSOP 145 45 °C/W 8-Lead SOIC 125 43 °C/W

Unit

JC

ESD CAUTION

Rev. 0 | Page 5 of 16

Analog Devices AD8667 Service Manual

FEATURES

APPLICATIONS

PIN CONFIGURATION

GENERAL DESCRIPTION

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

ABSOLUTE MAXIMUM RATINGS

THERMAL RESISTANCE

ESD CAUTION