Datasheet AD8278, AD8279 Datasheet (ANALOG DEVICES)

Low Power, Wide Supply Range,

Low Cost Difference Amplifiers, G = ½, 2

FEATURES

Wide input range beyond supplies Rugged input overvoltage protection Low supply current: 200 µA maximum (per amplifier) Low power dissipation: 0.5 mW at V Bandwidth: 1 MHz (G = ½) CMRR: 80 dB minimum, dc to 20 kHz (G = ½, B Grade) Low offset voltage drift: ±1 V/°C maximum (B Grade) Low gain drift: 1 ppm/°C maximum (B Grade) Enhanced slew rate: 1.4 V/µs Wide power supply range

Single supply: 2 V to 36 V Dual supplies: ±2 V to ±18 V

8-lead SOIC, 14-lead SOIC, and 8-lead MSOP packages

APPLICATIONS

Voltage measurement and monitoring Current measurement and monitoring Instrumentation amplifier building block Portable, battery-powered equipment Test and measurement

GENERAL DESCRIPTION

The AD8278 and AD8279 are general-purpose difference amplifiers intended for precision signal conditioning in power critical applications that require both high performance and low power. The AD8278 and AD8279 provide exceptional commonmode rejection ratio (80 dB) and high bandwidth while amplifying input signals that are well beyond the supply rails. The on-chip resistors are laser trimmed for excellent gain accuracy and high CMRR. They also have extremely low gain drift vs. temperature.

The common-mode range of the amplifier extends to almost triple the supply voltage (for G = ½), making the amplifer ideal for single-supply applications that require a high commonmode voltage range. The internal resistors and ESD circuitry at the inputs also provide overvoltage protection to the op amp.

The AD8278 and AD8279 can be used as difference amplifiers with G = ½ or G = 2. They can also be connected in a high precision, single-ended configuration for non inverting and inverting gains of

−½, −2, +3, +2, +1½, +1, or +½. The AD8278 and AD8279 provide an integrated precision solution that has a smaller size, lower cost, and better performance than a discrete alternative.

The AD8278 and AD8279 operate on single supplies (2.0 V to 36 V) or dual supplies (±2 V to ±18 V). The maximum quiescent supply current is 200 A, which is ideal for battery-operated and portable systems. For unity-gain difference amplifiers with similar performance, refer to the AD8276 and AD8277 data sheets.

Rev. B

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.

= 2.5 V

S

AD8278/AD8279

FUNCTIONAL BLOCK DIAGRAMS

+VS

7

40k 20k

2

–IN

40k

3 1

+IN

40k 20k

2

–INA

3 14

+INA

–INB

+INB

40k

40k 20k

6

5 8

40k

Table 1. Difference Amplifiers by Category

Low Distortion

High Voltage Current Sens ing

AD8270 AD628 AD8202 (U) AD8276 AD8271 AD629 AD8203 (U) AD8277 AD8273 AD8205 (B) AD8274 AD8206 (B) AMP03 AD8216 (B)

1

U = unidirectional, B = bidirectional.

The AD8278 is available in the space-saving 8-lead MSOP and SOIC packages, and the AD8279 is offered in a 14-lead SOIC package. Both are specified for performance over the industrial temperature range of −40°C to +85°C and are fully RoHS compliant.

AD8278

20k

4

–VS

Figure 1. AD8278

+VS

11

AD8279

20k

4

–VS

Figure 2. AD8279

5

SENSE

6

OUT

REF

12

SENSEA

13

OUTA

REFA

10

SENSEB

9

OUTB

REFB

1

Low Power

08308-001

08308-058

AD8278/AD8279

REVISION HISTORY

4/10—Rev. A to Rev. B

Changed Supply Current Parameters to AD8278 Supply Current

Parameter and AD8279 Supply Current Parameter, Table 5 ...... 6

Updated Outline Dimensions ....................................................... 20

10/09—Rev. 0 to Rev. A

Added AD8279 and 14-Lead SOIC Model ..................... Universal

Changes to Features .......................................................................... 1

Changes to General Description .................................................... 1

Change to Table 2 ............................................................................. 3

Change to Table 3 ............................................................................. 4

Change to Table 4 ............................................................................. 5

Typical Performance Characteristics ..............................................9

Theory of Operation ...................................................................... 16

Circuit Information .................................................................... 16

Driving the AD8278 and AD8279 ........................................... 16

Input Voltage Range ................................................................... 16

Power Supplies ............................................................................ 17

Applications Information .............................................................. 18

Configurations ............................................................................ 18 

Differential Output .................................................................... 19

Instrumentation Amplifier........................................................ 19

Outline Dimensions ....................................................................... 20

Ordering Guide .......................................................................... 21

Change to Table 5 .............................................................................. 6

Added Figure 6 and Table 9 ............................................................. 8

Changes to Figure 31 and Figure 32............................................. 13

Changes to Figure 40, Figure 41, and Figure 42 ......................... 14

Added Figure 47; Renumbered Sequentially .............................. 15

Changes to Figure 51 to Figure 57 ................................................ 18

Added Differential Output Section .............................................. 19

Changes to Figure 59 ...................................................................... 19

Updated Outline Dimensions ....................................................... 21

Changes to Ordering Guide .......................................................... 21

7/09—Revision 0: Initial Version

Rev. B | Page 2 of 24

AD8278/AD8279

SPECIFICATIONS

VS = ±5 V to ±15 V, V otherwise noted.

Table 2.

Parameter Conditions

INPUT CHARACTERISTICS

System Offset1 50 100 50 250 µV

Over Temperature TA = −40°C to +85°C 100 250 µV vs. Power Supply VS = ±5 V to ±18 V 2.5 5 µV/V Average Temperature

Coefficient T

Common-Mode Rejection

Ratio (RTI) Input Voltage Range2 −3 (VS + 0.1) +3 (VS − 1.5) −3 (VS + 0.1) +3 (VS − 1.5) V Impedance3

Differential 120 120 kΩ Common Mode 30 30 kΩ

DYNAMIC PERFORMANCE

Bandwidth 1 1 MHz Slew Rate 1.1 1.4 1.1 1.4 V/µs Channel Separation f = 1 kHz 130 130 dB Settling Time to 0.01% 10 V step on output,

Settling Time to 0.001% 10 10 µs

GAIN

Gain Error 0.005 0.02 0.01 0.05 % Gain Drift TA = −40°C to +85°C 1 5 ppm/°C Gain Nonlinearity V

OUTPUT CHARACTERISTICS

Output Voltage Swing4 V

Short-Circuit Current Limit ±15 ±15 mA Capacitive Load Drive 200 200 pF

NOISE5

Output Voltage Noise f = 0.1 Hz to 10 Hz 1.4 1.4 V p-p f = 1 kHz 47 50 47 50 nV/√Hz

POWER SUPPLY6

AD8278 Supply Current 200 200 A

Over Temperature TA = −40°C to +85°C 250 250 A

AD8279 Supply Current 300 350 300 350 A

Over Temperature TA = −40°C to +85°C 400 400 A

Operating Voltage Range7

TEMPERATURE RANGE

Operating Range −40 +125 −40 +125 °C

1

Includes input bias and offset current errors, RTO (referred to output).

2

The input voltage range may also be limited by absolute maximum input voltage or by the output swing. See the for details. Input Voltage Range

3

Internal resistors are trimmed to be ratio matched and have ±20% absolute accuracy.

4

Output voltage swing varies with supply voltage and temperature. See Figur through for details. e 22 Figure 25

5

Includes amplifier voltage and current noise, as well as noise from internal resistors.

6

Supply current varies with supply voltage and temperature. See Figure and for details. 26 Figure 28

7

Unbalanced dual supplies can be used, such as −VS = −0.5 V and +VS = +2 V. The positive supply rail must be at least 2 V above the negative supply and reference

voltage.

= 0 V, TA = 25°C, RL = 10 k connected to ground, G = ½ difference amplifier configuration, unless

REF

G = ½

Grade B Grade A

Min Typ Max Min Typ Max

= −40°C to +85°C 0.3 1 2 5 µV/°C

A

VS = ±15 V, VCM = ±27 V,

= 0 Ω 80 74 dB

R

S

= 100 pF

C

L

= 20 V p-p 7 12 ppm

OUT

= ±15 V, RL = 10 kΩ

S

= −40°C to +85°C −VS + 0.2 +VS − 0.2 −VS + 0.2 +VS − 0.2 V

T

A

9 9 µs

±2 ±18 ±2 ±18 V

Unit

Rev. B | Page 3 of 24

AD8278/AD8279

VS = ±5 V to ±15 V, V otherwise noted.

Table 3.

Parameter Conditions

INPUT CHARACTERISTICS

System Offset1 100 200 100 500 µV

Over Temperature TA = −40°C to +85°C 200 500 µV vs. Power Supply VS = ±5 V to ±18 V 5 10 µV/V Average Temperature

Coefficient

Common-Mode

Rejection Ratio (RTI) Input Voltage Range2 −1.5 (VS + 0.1) +1.5 (VS − 1.5) −1.5 (VS + 0.1) +1.5 (VS − 1.5) V Impedance3

Differential 120 120 kΩ

Common Mode 30 30 kΩ

DYNAMIC PERFORMANCE

Bandwidth 550 550 kHz Slew Rate 1.1 1.4 1.1 1.4 V/µs Channel Separation f = 1 kHz 130 130 dB Settling Time to 0.01% 10 V step on output,

Settling Time to 0.001% 11 11 µs

GAIN

Gain Error 0.005 0.02 0.01 0.05 % Gain Drift TA = −40°C to +85°C 1 5 ppm/°C Gain Nonlinearity V

OUTPUT CHARACTERISTICS

Output Voltage Swing4 VS = ±15 V, RL = 10 kΩ,

Short-Circuit Current

Limit Capacitive Load Drive 350 350 pF

NOISE5

Output Voltage Noise f = 0.1 Hz to 10 Hz 2.8 2.8 V p-p f = 1 kHz 90 95 90 95 nV/√Hz

POWER SUPPLY6

AD8278 Supply Current 200 200 A

Over Temperature TA = −40°C to +85°C 250 250 A AD8279 Supply Current 300 350 300 350 A

Over Temperature TA = −40°C to +85°C 400 400 A Operating Voltage Range7

TEMPERATURE RANGE

Operating Range −40 +125 −40 +125 °C

1

Includes input bias and offset current errors, RTO (referred to output).

2

The input voltage range may also be limited by absolute maximum input voltage or by the output swing. See the section for details. Input Voltage Range

3

Internal resistors are trimmed to be ratio matched and have ±20% absolute accuracy.

4

Output voltage swing varies with supply voltage and temperature. See Figur through for details. e 22 Figure 25

5

Includes amplifier voltage and current noise, as well as noise from internal resistors.

6

Supply current varies with supply voltage and temperature. See Figure and for details. 26 Figure 28

7

Unbalanced dual supplies can be used, such as −VS = −0.5 V and +VS = +2 V. The positive supply rail must be at least 2 V above the negative supply and reference

voltage.

= 0 V, TA = 25°C, RL = 10 k connected to ground, G = 2 difference amplifier configuration, unless

REF

G = 2

Grade B Grade A

Min Typ Max Min Typ Max

= −40°C to +85°C 0.6 2 2 5 µV/°C

T

A

VS = ±15 V, VCM = ±27 V,

= 0 Ω 86 80 dB

R

S

= 100 pF

C

L

= 20 V p-p 7 12 ppm

OUT

= −40°C to +85°C

T

A

−V

+ 0.2 +VS − 0.2 −VS + 0.2 +VS − 0.2 V

S

10 10 µs

±15 ±15 mA

±2 ±18 ±2 ±18 V

Unit

Rev. B | Page 4 of 24

AD8278/AD8279

VS = +2.7 V to <±5 V, V

otherwise noted.

Table 4.

Parameter Conditions

INPUT CHARACTERISTICS

System Offset1 75 150 75 250 µV

Over Temperature TA = −40°C to +85°C 150 250 µV vs. Power Supply VS = ±5 V to ±18 V 2.5 5 µV/V Average Temperature

Coefficient

Common-Mode Rejection

Ratio (RTI)

V

Input Voltage Range2 −3 (VS + 0.1) +3 (VS − 1.5) −3 (VS + 0.1) +3 (VS − 1.5) V Impedance3

Differential 120 120 kΩ Common Mode 30 30 kΩ

DYNAMIC PERFORMANCE

Bandwidth 870 870 kHz Slew Rate 1.3 1.3 V/µs Channel Separation f = 1 kHz 130 130 dB Settling Time to 0.01% 2 V step on output,

GAIN

Gain Error 0.005 0.02 0.01 0.05 % Gain Drift TA = −40°C to +85°C 1 5 ppm/°C

OUTPUT CHARACTERISTICS

Output Swing4 R

Short-Circuit Current Limit ±10 ±10 mA Capacitive Load Drive 200 200 pF

NOISE5

Output Voltage Noise f = 0.1 Hz to 10 Hz 1.4 1.4 V p-p f = 1 kHz 47 50 47 50 nV/√Hz

POWER SUPPLY6

AD8278 Supply Current TA = −40°C to +85°C 200 200 A AD8279 Supply Current TA = −40°C to +85°C 375 375 A Operating Voltage Range 2.0 36 2.0 36 V

TEMPERATURE RANGE

Operating Range −40 +125 −40 +125 °C

1

Includes input bias and offset current errors, RTO (referred to output).

2

The input voltage range may also be limited by absolute maximum input voltage or by the output swing. See the section for details. Input Voltage Range

3

Internal resistors are trimmed to be ratio matched and have ±20% absolute accuracy.

4

Output voltage swing varies with supply voltage and temperature. See Figur through for details. e 22 Figure 25

5

Includes amplifier voltage and current noise, as well as noise from internal resistors.

6

Supply current varies with supply voltage and temperature. See Figure and for details. 27 Figure 28

= midsupply, TA = 25°C, RL = 10 k connected to midsupply, G = ½ difference amplifier configuration, unless

REF

G = ½

Grade B Grade A

Min Typ Max Min Typ Max

= −40°C to +85°C 0.3 1 2 5 µV/°C

T

A

VS = 2.7 V, VCM = 0 V to

= 0 Ω 80 74 dB

2.4 V, R

S

= ±5 V, VCM = −10 V

S

to +7 V, R

= 0 Ω 80 74 dB

S

= 100 pF, VS = 2.7 V

C

L

= 10 kΩ,

L

= −40°C to +85°C −VS + 0.1 +VS − 0.15 −VS + 0.1 +VS − 0.15 V

T

A

7 7 µs

Unit

Rev. B | Page 5 of 24

AD8278/AD8279

VS = +2.7 V to <±5 V, V otherwise noted.

Table 5.

Parameter Conditions

INPUT CHARACTERISTICS

System Offset1 150 300 150 500 µV

Over Temperature TA = −40°C to +85°C 300 500 µV

vs. Power Supply VS = ±5 V to ±18 V 5 10 µV/V

Average Temperature

Coefficient

Common-Mode Rejection

Ratio (RTI) V

Input Voltage Range2 −1.5 (VS + 0.1) +1.5 (VS − 1.5) −1.5 (VS + 0.1) +1.5 (VS − 1.5) V Impedance3

Differential 120 120 kΩ

Common Mode 30 30 kΩ

DYNAMIC PERFORMANCE

Bandwidth 450 450 kHz Slew Rate 1.3 1.3 V/µs Channel Separation f = 1 kHz 130 130 dB Settling Time to 0.01% 2 V step on output,

GAIN

Gain Error 0.005 0.02 0.01 0.05 % Gain Drift TA = −40°C to +85°C 1 5 ppm/°C

OUTPUT CHARACTERISTICS

Output Swing4 R

Short-Circuit Current Limit ±10 ±10 mA Capacitive Load Drive 200 200 pF

NOISE5

Output Voltage Noise f = 0.1 Hz to 10 Hz 2.8 2.8 V p-p f = 1 kHz 94 100 94 100 nV/√Hz

POWER SUPPLY6

AD8278 Supply Current TA = −40°C to +85°C 200 200 A AD8279 Supply Current TA = −40°C to +85°C 375 375 A Operating Voltage Range 2.0 36 2.0 36 V

TEMPERATURE RANGE

Operating Range −40 +125 −40 +125 °C

1

Includes input bias and offset current errors, RTO (referred to output).

2

The input voltage range may also be limited by absolute maximum input voltage or by the output swing. See the section for details. Input Voltage Range

3

Internal resistors are trimmed to be ratio matched and have ±20% absolute accuracy.

4

Output voltage swing varies with supply voltage and temperature. See Figur through for details. e 22 Figure 25

5

Includes amplifier voltage and current noise, as well as noise from internal resistors.

6

Supply current varies with supply voltage and temperature. See Figure and for details. 27 Figure 28

= midsupply, TA = 25°C, RL = 10 k connected to midsupply, G = 2 difference amplifier configuration, unless

REF

G = 2

Grade B Grade A

Min Typ Max Min Typ Max

= −40°C to +85°C 0.6 2 3 5 µV/°C

T

A

VS = 2.7 V, VCM = 0 V to 2.4 V, R

= ±5 V, VCM = −10 V

S

to +7 V, R

= 0 Ω 86 80 dB

S

= 0 Ω 86 80 dB

S

= 100 pF, VS = 2.7 V

C

L

= 10 kΩ,

L

= −40°C to +85°C −VS + 0.1 +VS − 0.15 −VS + 0.1 +VS − 0.15 V

T

A

9 9 µs

Unit

Rev. B | Page 6 of 24

AD8278/AD8279

ABSOLUTE MAXIMUM RATINGS

2.0

Table 6.

Parameter Rating

Supply Voltage ±18 V

Maximum Voltage at Any Input Pin −VS + 40 V

Minimum Voltage at Any Input Pin +VS − 40 V

Storage Temperature Range −65°C to +150°C

Specified Temperature Range −40°C to +85°C

Package Glass Transition Temperature (TG) 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

The θJA values in Tabl e 7 assume a 4-layer JEDEC standard

board with zero airflow.

Table 7. Thermal Resistance

Package Type θJA Unit

8-Lead MSOP 135 °C/W

8-Lead SOIC 121 °C/W

14-Lead SOIC 105 °C/W

MAXIMUM POWER DISSIPATION

The maximum safe power dissipation for the AD8278 and

AD8279 are limited by the associated rise in junction tempera-

ture (T

) on the die. At approximately 150°C, which is the glass

J

transition temperature, the properties of the plastic change.

Even temporarily exceeding this temperature limit may change

the stresses that the package exerts on the die, permanently shifting

the parametric performance of the amplifiers. Exceeding a

temperature of 150°C for an extended period may result in a

loss of functionality.

1.6

1.2

0.8

0.4

MAXIMUM POWER DISSIPATION (W)

0

–50 0–25 255075100125

Figure 3. Maximum Power Dissipation vs. Ambient Temperature

SHORT-CIRCUIT CURRENT

The AD8278 and AD8279 have built-in, short-circuit protection that limits the output current (see Figure 29 for more information). While the short-circuit condition itself does not damage the part, the heat generated by the condition can cause the part to exceed its maximum junction temperature, with corresponding negative effects on reliability. Figure 3 and Figure 29, combined with knowledge of the supply voltages and ambient temperature of the part, can be used to determine whether a short circuit will cause the part to exceed its maximum junction temperature.

ESD CAUTION

TJ MAX = 150°C

SOIC

= 121°C/W



JA

MSOP



= 135°C/W

JA

AMBIENT TEMERATURE (°C)

08308-002

Rev. B | Page 7 of 24

AD8278/AD8279

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

REF

1

2

–IN

+IN

3

(Not to Scale)

–VS

4

NC = NO CONNECT

AD8278

TOP VIEW

8

7

6

5

NC

+VS

OUT

SENSE

8308-003

Figure 4. MSOP Pin Configuration

Table 8. AD8278 Pin Function Descriptions

Pin No. Mnemonic Description

1 REF Reference Voltage Input. 2 −IN Inverting Input. 3 +IN Noninverting Input. 4 −VS Negative Supply. 5 SENSE Sense Terminal. 6 OUT Output. 7 +VS Positive Supply. 8 NC No Connect.

1

AD8278

–IN

2

TOP VIEW

+IN

3

(Not to Scale)

4

–VS

NC = NO CONNECT

Figure 5. SOIC Pin Configuration

8

7

6

5

NC

+VS

OUT

SENSE

8308-004

1

NC

2

–INA

3

+INA

4

–VS

5 10

+INB

6 9

–INB

7 8

NC

NC = NO CONNECT

Figure 6. 14-Lead SOIC Pin Configuration

Table 9. AD8279 Pin Function Descriptions

Pin No. Mnemonic Description

1 NC No Connect. 2 −INA Channel A Inverting Input. 3 +INA Channel A Noninverting Input. 4 −VS Negative Supply. 5 +INB Channel B Noninverting Input. 6 −INB Channel B Inverting Input. 7 NC No Connect. 8 REFB Channel B Reference Voltage Input. 9 OUTB Channel B Output. 10 SENSEB Channel B Sense Terminal. 11 +VS Positive Supply. 12 SENSEA Channel A Sense Terminal. 13 OUTA Channel A Output. 14 REFA Channel A Reference Voltage Input.

AD8279

TOP VIEW

(Not to Scale)

14

13

12

11

REFA

OUTA

SENSEA

+VS

SENSEB

OUTB

REFB

08308-059

Rev. B | Page 8 of 24

AD8278/AD8279

TYPICAL PERFORMANCE CHARACTERISTICS

VS = ±15 V, TA = 25°C, RL = 10 kΩ connected to ground, G = ½ difference amplifier configuration, unless otherwise noted.

600

500

400

300

200

NUMBER OF HITS

100

0

–150 –100 –50 0 50 100 150

SYSTEM OFFSET VOLTAGE (µV)

N = 3840 MEAN = –16.8 SD = 41.7673

Figure 7. Distribution of Typical System Offset Voltage, G = 2

800

700

600

500

400

300

NUMBER OF HITS

200

100

0

–60 –40 –20 0 20 40 60

CMRR (µV/V)

N = 3837 MEAN = 7.78 SD = 13.569

Figure 8. Distribution of Typical Common-Mode Rejection, G = 2

10

08308-005

08308-006

80

60

40

20

0

–20

–40

SYSTEM OFFSET (µV)

–60

–80

REPRESENTATIVE DATA

–100

–50 –35 –20 –5 10 25 40 55 70 85

TEMPERATURE (°C)

Figure 10. System Offset vs. Temperature, Normalized at 25°, G = ½

20

15

10

5

0

–5

–10

GAIN ERROR (µV/V)

–15

–20

–25

REPRESENTATIVE DATA

–30

–50 –35 –20 –5 10 25 40 55 70 85

TEMPERATURE (°C)

Figure 11. Gain Error vs. Temperature, Normalized at 25°C, G = ½

30

08308-008

08308-009

5

0

–5

CMRR (µV/V)

–10

–15

REPRESENTATIVE DATA

–20

–50–35–20–5102540557085

TEMPERATURE (° C)

Figure 9. CMRR vs. Temperature, Normalized at 25°C, G = ½

08308-007

Rev. B | Page 9 of 24

20

10

0

–10

COMMON-MODE VOLTAGE (V)

–20

–30

–20 –15 –10 –5 0 5 10 15 20

VS = ±5V

OUTPUT VOL TAGE (V)

VS = ±15V

Figure 12. Input Common-Mode Voltage vs. Output Voltage,

±15 V and ±5 V Supplies, G = ½

08308-010

AD8278/AD8279

10

8

6

4

2

0

–2

–4

COMMON-MODE VOLTAGE (V)

–6

–8

–10

–0.5 0.5 1.5 2.5 3.5 4.5 5.5

VS = 2.7V

VS = 5V

OUTPUT VO LTAGE (V )

= MIDSUPPLY

V

REF

Figure 13. Input Common-Mode Voltage vs. Output Voltage,

5 V and 2.7 V Supplies, V

12

10

8

6

4

2

0

–2

COMMON-MODE VOLTAGE (V)

–4

–6

–0.5 0.5 1.5 2.5 3.5 4.5 5.5

VS = 2.7V

OUTPUT VO LTAGE (V )

= Midsupply, G = ½

REF

VS = 5V

V

= 0V

REF

Figure 14. Input Common-Mode Voltage vs. Output Voltage,

VS = ±5V

= 0 V, G = ½

REF

5 V and 2.7 V Supplies, V

30

20

10

0

–10

COMMON-MODE VOLTAGE (V)

–20

–30

–20 –15 –10 –5 0 10 20515

VS = ±15V

OUTPUT VOL TAGE (V)

Figure 15. Input Common-Mode Voltage vs. Output Voltage,

±15 V and ±5 V Supplies, G = 2

08308-011

08308-012

08308-013

5

4

3

2

1

0

–1

COMMON-MODE VOLTAGE (V)

–2

–3

–0.5 0.5 1.5 2.5 3.5 4.5 5.5

VS = 2.7V

VS = 5V

OUTPUT VO LTAGE (V )

V

= MIDSUPPLY

REF

Figure 16. Input Common-Mode Voltage vs. Output Voltage,

5 V and 2.7 V Supplies, V

6

5

4

3

2

1

0

COMMON-MODE VOLTAGE (V)

–1

–2

–0.5 0.5 1.5 2.5 3.5 4.5 5.5

VS = 2.7V

OUTPUT VO LTAGE (V )

= Midsupply, G = 2

REF

VS = 5V

V

REF

Figure 17. Input Common-Mode Voltage vs. Output Voltage,

= 0 V, G = 2

REF

18

12

GAIN = 2

6

0

GAIN = ½

–6

–12

GAIN (dB)

–18

–24

–30

–36

100 10M1M100k10k1k

5 V and 2.7 V Supplies, V

FREQUENCY (Hz)

Figure 18. Gain vs. Frequency, ±15 V Supplies

08308-014

= 0V

08308-015

08308-016

Rev. B | Page 10 of 24

AD8278/AD8279

V

18

12

GAIN = 2

6

0

GAIN = ½

–6

–12

GAIN (dB)

–18

–24

–30

–36

100 10M1M100k10k1k

FREQUENCY (Hz)

Figure 19. Gain vs. Frequency, +2.7 V Single Supply

120

GAIN = 2

100

GAIN = ½

80

60

CMRR (dB)

40

20

0

11M100k10k1k10010

FREQUENCY (Hz)

Figure 20. CMRR vs. Frequency

120

08308-017

08308-018

+

S

–0.1

–0.2

–0.3

–0.4

TA = –40°C TA = +25°C TA = +85°C

+0.4

+0.3

OUTPUT VO LTAGE SWING (V)

+0.2

REFERRED TO SUPPLY VOLTAGES

+0.1

–V

S

2116141210864

SUPPLY VOLTAGE (±VS)

TA = +125°C

8

Figure 22. Output Voltage Swing vs. Supply Voltage and Temperature,

= 10 kΩ

R

L

+

S

–0.2

–0.4

–0.6

–0.8

–1.0

–1.2

+1.2

+1.0

+0.8

OUTPUT VOLTAGE SWING (V)

+0.6

REFERRED TO SUPPLY VOLTAGES

+0.4

+0.2

–V

S

2116141210864

SUPPLY VOLTAGE (±VS)

TA = –40°C TA = +25°C TA = +85°C TA = +125°C

8

Figure 23. Output Voltage Swing vs. Supply Voltage and Temperature,

= 2 kΩ

R

L

+

S

08308-020

08308-021

100

80

60

PSRR (dB)

40

20

0

11M100k10k1k10010

–PSRR

+PSRR

FREQUENCY (Hz)

Figure 21. PSRR vs. Frequency

08308-019

–4

–8

+8

OUTPUT VOLTAGE SWING (V)

+4

REFERRED TO SUPPLY VOLTAGES

–V

S

1k 100k10k

LOAD RESIST ANCE ()

Figure 24. Output Voltage Swing vs. R

TA = –40°C TA = +25°C TA = +85°C TA = +125°C

and Temperature, VS = ±15 V

L

08308-022

Rev. B | Page 11 of 24

AD8278/AD8279

V

+

S

–0.5

–1.0

–1.5

–2.0

+2.0

+1.5

OUTPUT VOLTAGE SWING (V)

+1.0

REFERRED TO SUPPLY VOLTAGES

+0.5

–V

S

01987654321 0

Figure 25. Output Voltage Swing vs. I

180

170

160

150

140

SUPPLY CURRENT (µA)

130

120

01161412108642

OUTPUT CURRENT (mA)

and Temperature, VS = ±15 V

OUT

SUPPLY VOLTAGE (±V)

TA = –40°C TA = +25°C TA = +85°C TA = +125°C

8

08308-024

Figure 26. Supply Current per Channel vs. Dual-Supply Voltage, VIN = 0 V

180

170

160

150

140

SUPPLY CURRENT (µA)

130

120

043530252015105

SUPPLY VOLTAGE (V)

0

08308-025

Figure 27. Supply Current per Channel vs. Single-Supply Voltage, VIN = 0 V,

V

= 0 V

REF

08308-023

250

200

150

VS = ±15V

100

SUPPLY CURRENT (µA)

50

0 –50 –30 –10 10 30 50 70 90 110 130

V

= +2.7V

S

TEMPERATURE (° C)

V

= MIDSUPPLY

REF

Figure 28. Supply Current per Channel vs. Temperature

30

25

20

15

10

5

0

–5

–10

SHORT-CIRCUIT CURRENT (mA)

–15

–20

–50 –30 –10 10 30 50 70 90 110 130

I

SHORT+

I

SHORT–

TEMPERATURE (° C)

Figure 29. Short-Circuit Current per Channel vs. Temperature

2.0

1.8

1.6

1.4

1.2

1.0

0.8

SLEW RATE (V/µ s)

0.6

0.4

0.2

0

–50 –30 –10 10 30 50 70 90 110 130

–SLEW RATE

+SLEW RATE

TEMPERATURE ( °C)

Figure 30. Slew Rate vs. Temperature, VIN = 20 V p-p, 1 kHz

08308-026

08308-027

08308-028

Rev. B | Page 12 of 24

AD8278/AD8279

10

8

6

4

2

0

–2

–4

NONLINEARIT Y (2ppm/DI V)

–6

–8

–10

–5 –4 –3 –2 –1 0 1 2 3 4 5

OUTPUT VOLTAGE (V)

Figure 31. Gain Nonlinearity, V

20

16

12

8

4

0

–4

–8

NONLINEARIT Y (2ppm/DIV)

–12

–16

–20

–5 –4 –3 –2 –1 0 1 2 3 4 5

OU T PU T V OLTA G E ( V)

= ±15 V, RL ≥ 2 kΩ, G = ½

S

Figure 32. Gain Nonlinearity, VS = ±15 V, RL ≥ 2 kΩ, G = 2

08308-029

08308-030

1V/DIV

3.64µs TO 0. 01%

4.12µs TO 0 .001%

0.002%/DIV

4µs/DIV

TIME (µs)

8308-032

Figure 34. Large Signal Pulse Response and Settling Time, 2 V Step,

= 2.7 V, G = ½

V

S

5V/DIV

7.6µs TO 0.01%

9.68µs TO 0 .001%

0.002%/DIV

40µs/DIV

TIME (µs)

8308-033

Figure 35. Large Signal Pulse Response and Settling Time, 10 V Step,

V

= ±15 V, G = 2

S

5V/DIV

6.24µs TO 0. 01%

7.92µs TO 0 .001%

0.002%/DIV

40µs/DIV

TIME (µs)

8308-031

Figure 33. Large Signal Pulse Response and Settling Time, 10 V Step,

= ±15 V, G = ½

V

S

Rev. B | Page 13 of 24

1V/DIV

4.34µs TO 0. 01%

5.12µs TO 0 .001%

0.002%/DIV

4µs/DIV

TIME (µs)

08308-034

Figure 36. Large Signal Pulse Response and Settling Time, 2 V Step,

= 2.7 V

V

S

AD8278/AD8279

V

5.0 VS = 5V

4.5

4.0

3.5

3.0 VS = 2.7V

2V/DI

10µs/DIV

Figure 37. Large Signal Step Response, G = ½

08308-035

2.5

2.0

1.5

OUTPUT VOLTAGE (V p-p)

1.0

0.5

0

100 1M100k10k1k

FREQUENCY (Hz)

Figure 40. Maximum Output Voltage vs. Frequency, V

= 5 V, 2.7 V

S

08308-038

5V/DI

10µs/DIV

08308-036

Figure 38. Large Signal Step Response, G = 2

30

VS = ±15V

25

20

15

VS = ±5V

10

OUTPUT VOLTAGE (V p-p)

5

0

100 1M100k10k1k

FREQUENCY (Hz)

Figure 39. Maximum Output Voltage vs. Frequency, VS = ±15 V, ±5 V

20mV/DI

NO LOAD

CL = 100pF

CL = 147pF

CL = 247pF

40µs/DIV

08308-039

Figure 41. Small Signal Step Response for Various Capacitive Loads, G = ½

20mV/DI

CL = 100pF

C

= 200pF

L

C

= 247pF

L

C

= 347pF

L

40µs/DIV

08308-037

08308-040

Figure 42. Small Signal Step Response for Various Capacitive Loads, G = 2

Rev. B | Page 14 of 24

AD8278/AD8279

V

50

2k LOAD

GAIN = 2

GAIN = ½

1s/DIV

08308-044

45

40

35

30

25

20

OVERSHOOT (%)

15

10

5

0

02150 20010050

CAPACITIVE L OAD (pF)

±2V

±5V

±15V

±18V

50

Figure 43. Small Signal Overshoot vs. Capacitive Load, RL ≥ 2 kΩ, G = ½

35

30

25

20

15

OVERSHOOT (%)

10

5

±5V

±2V

±15V

±18V

1µV/DI

08308-041

Figure 46. 0.1 Hz to 10 Hz Voltage Noise

160

140

120

100

80

60

40

CHANNEL SEPARATION (dB)

20

0

0350150 250 30020010050

CAPACITIVE L OAD (pF)

Figure 44. Small Signal Overshoot vs. Capacitive Load, R

1k

100

NOISE (nV/ Hz)

10

0.1 100k10k1k100101

GAIN = 2

GAIN = ½

FREQUENCY (Hz)

Figure 45. Voltage Noise Density vs. Frequency

≥ 2 kΩ, G = 2

L

0

10 100 1k 10k 100k

08308-042

FREQUENCY ( Hz)

08308-060

Figure 47. Channel Separation

08308-043

Rev. B | Page 15 of 24

AD8278/AD8279

THEORY OF OPERATION

CIRCUIT INFORMATION

Each channel of the AD8278 and AD8279 consists of a low power, low noise op amp and four laser-trimmed on-chip resistors. These resistors can be externally connected to make a variety of amplifier configurations, including difference, noninverting, and inverting configurations. Taking advantage of the integrated resistors of the AD8278 and AD8279 provides the designer with several benefits over a discrete design, including smaller size, lower cost, and better ac and dc performance.

+VS

7

40k 20k

2

–IN

40k

3 1

+IN

Figure 48. Functional Block Diagram

DC Performance

Much of the dc performance of op amp circuits depends on the accuracy of the surrounding resistors. Using superposition to analyze a typical difference amplifier circuit, as is shown in Figure 49, the output voltage is found to be

⎛

R2

⎜

VV

=

OUT

⎜

+

⎝

This equation demonstrates that the gain accuracy and commonmode rejection ratio of the AD8278 and AD8279 is determined primarily by the matching of resistor ratios. Even a 0.1% mismatch in one resistor degrades the CMRR to 69 dB for a G = 2 difference amplifier.

The difference amplifier output voltage equation can be reduced to

R4

V

OUT

()

R3

as long as the following ratio of the resistors is tightly matched:

R4

R2

R1

=

R3

The resistors on the AD8278 and AD8279 are laser trimmed to match accurately. As a result, the AD8278 and AD8279 provide superior performance over a discrete solution, enabling better CMRR, gain accuracy, and gain drift, even over a wide temperature range.

AD8278

5

SENSE

6

OUT

20k

4

–VS

⎞

R4

⎛

⎟

+

1

⎜

⎟

R2R1

VV

R3

⎝

⎠

−+−=ININ

REF

08308-045

R4

⎞

⎞ ⎟ ⎠

⎛

−

V

⎟

⎜

−+

ININ

R3

⎠

⎝

AC Performance

Component sizes and trace lengths are much smaller in an IC than on a PCB; therefore, the corresponding parasitic elements are also smaller. This results in better ac performance of the AD8278 and AD8279. For example, the positive and negative input terminals of the AD8278 and AD8279 op amps are intentionally not pinned out. By not connecting these nodes to the traces on the PCB, their capacitance remains low and balanced, resulting in improved loop stability and excellent common-mode rejection over frequency.

DRIVING THE AD8278 AND AD8279

Care should be taken to drive the AD8278 and AD8279 with a low impedance source, for example, another amplifier. Source resistance of even a few kilohms (kΩ) can unbalance the resistor ratios and, therefore, significantly degrade the gain accuracy and common-mode rejection of the AD8278 and AD8279. Because all configurations present several kilohms (kΩ) of input resistance, the AD8278 and AD8279 do not require a high current drive from the source and are easy to drive.

INPUT VOLTAGE RANGE

The AD8278 and AD8279 are able to measure input voltages beyond the supply rails. The internal resistors divide down the voltage before it reaches the internal op amp and provide protection to the op amp inputs. Figure 49 shows an example of how the voltage division works in a difference amplifier configuration. For the AD8278 and AD8279 to measure correctly, the input voltages at the input nodes of the internal op amp must stay below 1.5 V of the positive supply rail and can exceed the negative supply rail by 0.1 V. Refer to the Power Supplies section for more details.

R2

(V

)

IN+

R1 + R2

R3

V

IN–

R1

V

IN+

Figure 49. Voltage Division in the Difference Amplifier Configuration

R2

The AD8278 and AD8279 have integrated ESD diodes at the inputs that provide overvoltage protection. This feature simplifies system design by eliminating the need for additional external protection circuitry and enables a more robust system.

The voltages at any of the inputs of the parts can safely range from +V

− 40 V up to −VS + 40 V. For example, on ±10 V

S

supplies, input voltages can go as high as ±30 V. Care should be taken to not exceed the +V

− 40 V to −VS + 40 V input limits

S

to avoid damaging the parts.

R2

R1 + R2

R4

(V

)

IN+

08308-062

Rev. B | Page 16 of 24

AD8278/AD8279

POWER SUPPLIES

The AD8278 and AD8279 operate extremely well over a very wide range of supply voltages. They can operate on a single supply as low as 2 V and as high as 36 V, under appropriate setup conditions.

For best performance, the user should ensure that the internal op amp is biased correctly. The internal input terminals of the op amp must have sufficient voltage headroom to operate properly. Proper operation of the part requires at least 1.5 V between the positive supply rail and the op amp input terminals. This relationship is expressed in the following equation:

R1

+

R2R1

REF

VV

For example, when operating on a +V V

= 0 V, it can be seen from Figure 50 that the op amp input

REF

terminals are biased at 0 V, allowing more than the required 1.5 V headroom. However, if V input terminals of the op amp are biased at 0.66 V (G = ½). Now the op amp does not have the required 1.5 V headroom and cannot function. Therefore, the user must increase the supply voltage or decrease V

to restore proper operation.

REF

V5.1−+<

S

REF

= 2 V single supply and

S

= 1 V under the same conditions, the

The AD8278 and AD8279 are typically specified at single and dual supplies, but they can be used with unbalanced supplies as well; for example, −V

= −5 V, +VS = +20 V. The difference between

S

the two supplies must be kept below 36 V. The positive supply rail must be at least 2 V above the negative supply.

R1

(V

)

REF

R1 + R2

R3

R1

R2

V

REF

Figure 50. Ensure Sufficient Voltage Headroom on the Internal Op Amp

R1 + R2

Inputs

R4

R1

(V

)

REF

08308-046

Use a stable dc voltage to power the AD8278 and AD8279. Noise on the supply pins can adversely affect performance. Place a bypass capacitor of 0.1 µF between each supply pin and ground, as close as possible to each supply pin. Use a tantalum capacitor of 10 µF between each supply and ground. It can be farther away from the supply pins and, typically, it can be shared by other precision integrated circuits.

Rev. B | Page 17 of 24

AD8278/AD8279

V

APPLICATIONS INFORMATION

CONFIGURATIONS

The AD8278 and AD8279 can be configured in several ways (see Figure 51 to Figure 57). These configurations have excellent gain accuracy and gain drift because they rely on the internal matched resistors. Note that Figure 53 shows the AD8278 and AD8279 as difference amplifiers with a midsupply reference voltage at the noninverting input. This allows the AD8278 and AD8279 to be used as a level shifter, which is appropriate in single-supply applications that are referenced to midsupply. Tabl e 10 lists several single-ended amplifier configurations that are not illustrated.

40k

2

–IN

40k 20k

3

+IN

V

= ½ (V

OUT

Figure 51. Difference Amplifier, Gain = ½

20k

5

–IN

20k 40k

1

+IN

V

= 2(V

OUT

IN+

Figure 52. Difference Amplifier, Gain = 2

40k

2

–IN

40k 20k

3

+IN

AD8278

= ½ (V

IN+

 V

OUT

Figure 53. Difference Amplifier, Gain = ½, Referenced to Midsupply

AD8278

 V

IN+

AD8278

 V

IN

20k

) + V

IN

20k

5

OUT

6

1

)

IN

40k

2

6

3

)

5

OUT

6

1

V

= MIDSUPPLY

REF

OUT

08308-047

08308-048

08308-049

Figure 54. Difference Amplifier, Gain = 2, Referenced to Midsupply

–IN

+IN

OUT

= 2 (V

IN

20k

5

20k 40k

1

IN+

2

1

3

AD8278

 V

) + V

IN

40k

20k

40k

REF

20k

2

OUT

6

3

V

= MIDSUPPLY

REF

5

6

OUT

AD8278

V

= –½V

OUT

IN

8308-051

Figure 55. Inverting Amplifier, Gain = −½

40k

25

20k

1

IN

40k

3

20k

OUT

6

AD8278

= 1.5V

V

OUT

IN

Figure 56. Noninverting Amplifier, Gain = 1.5

5

1

IN

20k

20k 40k

40k

2

OUT

6

3

AD8278

= 2V

OUT

IN

Figure 57. Noninverting Amplifier, Gain = 2

08308-050

08308-052

8308-053

Table 10. AD8278 Difference and Single-Ended Amplifier Configurations

Amplifier Configuration Signal Gain Pin 1 (REF) Pin 2 (VIN−) Pin 3 (VIN+) Pin 5 (SENSE)

Difference Amplifier +½ GND IN− IN+ OUT Difference Amplifier +2 IN+ OUT GND IN− Single-Ended Inverting Amplifier −½ GND IN GND OUT Single-Ended Inverting Amplifier −2 GND OUT GND IN Single-Ended Noninverting Amplifier +3⁄2 IN GND IN OUT Single-Ended Noninverting Amplifier +3 IN OUT IN GND Single-Ended Noninverting Amplifier +½ GND GND IN OUT Single-Ended Noninverting Amplifier +1 IN GND GND OUT Single-Ended Noninverting Amplifier +1 GND OUT IN GND Single-Ended Noninverting Amplifier +2 IN OUT GND GND

Rev. B | Page 18 of 24

AD8278/AD8279

The reference must be driven with a low impedance source to maintain the internal resistor ratio. An example using the low power, low noise OP1177 as a reference is shown in Figure 58.

INCORRECT

AD8278

REF

V

Figure 58. Driving the Reference Pin

V

CORRECT

AD8278

+

OP1177

–

REF

8308-054

DIFFERENTIAL OUTPUT

The two difference amplifiers of the AD8279 can be configured to provide a differential output, as shown in Figure 59. This differential output configuration is suitable for various applications, such as strain gage excitation and single-ended-to-differential conversion. The differential output voltage has a gain twice that of a single AD8279 channel, as shown in the following equation:

V

If the AD8279 amplifiers are each configured for G = ½, the differential gain is 1×; if the AD8279 amplifiers are each configured for G = 2, the differential gain is 4×.

DIFF_OUT

–IN

+IN

= V

− V

+OUT

−OUT

+VS

20k 40k

12

20k

14 3

20k 40k

10

= 2 × G

11

AD8279

40k

AD8279

× (V

2

13

6

IN+

– V

+OUT

IN−

)

INSTRUMENTATION AMPLIFIER

The AD8278 and AD8279 can be used as building blocks for a low power, low cost instrumentation amplifier. An instrumentation amplifier provides high impedance inputs and delivers high common-mode rejection. Combining the AD8278 with an Analog Devices, Inc., low power amplifier (see Ta b le 1 1 ) creates a precise, power efficient voltage measurement solution suitable for power critical systems.

–IN

R

+IN

Figure 60. Low Power Precision Instrumentation Amplifier

Table 11. Low Power Op Amps

Op Amp (A1, A2) Features

AD8506 Dual micropower op amp AD8607 Precision dual micropower op amp AD8617 Low cost CMOS micropower op amp AD8667 Dual precision CMOS micropower op amp

It is preferable to use dual op amps for the high impedance inputs because they have better matched performance and track each other over temperature. The AD8278 and AD8279 difference amplifiers cancel out common-mode errors from the input op amps, if they track each other. The differential gain accuracy of the in-amp is proportional to how well the input feedback resistors (R increases as the differential gain is increased (1 + 2R higher gain also reduces the common-mode voltage range.

Refer to

A Designer’s Guide to Instrumentation Amplifiers for

more design ideas and considerations at www.analog.com, under Technical Documentation.

A1

R

F

G

R

F

A2

) match each other. The CMRR of the in-amp

F

20k

40k

V

= (1 + 2RF/RG) (V

OUT

REF

40k

AD8278/

AD8279

IN+

– V

IN–

V

) × 2

F/RG

OUT

), but a

08308-056

20k

8 5

40k

4

–VS

Figure 59. AD8279 Differential Output G = 4 Configuration

9

–OUT

08308-061

Rev. B | Page 19 of 24

AD8278/AD8279

OUTLINE DIMENSIONS

5.00 (0.1968)

4.80 (0.1890)

4.00 (0.1574)

3.80 (0.1497)

0.25 (0.0098)

0.10 (0.0040)

COPLANARITY

0.10

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

85

1

1.27 (0.0500)

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012-AA

BSC

6.20 (0.2441)

5.80 (0.2284)

4

1.75 (0.0688)

1.35 (0.0532)

0.51 (0.0201)

0.31 (0.0122)

8° 0°

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0196)

0.25 (0.0099)

1.27 (0.0500)

0.40 (0.0157)

45°

012407-A

Figure 61. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body (R-8)

Dimensions shown in millimeters and (inches)

3.20

3.00

2.80

8

5

3.20

3.00

2.80

PIN 1

IDENTIFIER

0.95

0.85

0.75

0.15

0.05

COPLANARITY

1

0.65 BSC

0.10

COMPLIANT TO JEDEC STANDARDS MO-187-AA

Figure 62. 8-Lead Mini Small Outline Package [MSOP]

5.15

4.90

4.65

4

15° MAX

6° 0°

0.23

0.09

0.40

0.25

1.10 MAX

(RM-8)

Dimensions shown in millimeters

0.80

0.55

0.40

100709-B

Rev. B | Page 20 of 24

AD8278/AD8279

4.00 (0.1575)

3.80 (0.1496)

0.25 (0.0098)

0.10 (0.0039)

COPLANARIT Y

0.10

CONTROLLING DIMENSIONSARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-O FF MIL LIMETE R EQUIVALENTS FOR REFERENCE ON LY AND ARE NOT APPROPRI ATE FOR USE IN DESIGN.

8.75 (0.3445)

8.55 (0.3366)

BSC

8

6.20 (0.2441)

5.80 (0.2283)

7

1.75 (0.0689)

1.35 (0.0531)

SEATING PLANE

0.25 (0.0098)

0.17 (0.0067)

14

1

1.27 (0.0500)

0.51 (0.0201)

0.31 (0.0122)

COMPLIANT TO JEDEC STANDARDS MS-012-AB

0.50 (0.0197)

0.25 (0.0098)

8° 0°

1.27 (0.0500)

0.40 (0.0157)

45°

060606-A

Figure 63. 14-Lead Standard Small Outline Package [SOIC_N]

Narrow Body (R-14)

Dimensions shown in millimeters and (inches)

ORDERING GUIDE

Model1 Temperature Range Package Description Package Option Branding

AD8278ARZ −40°C to +85°C 8-Lead SOIC_N R-8 AD8278ARZ-R7 −40°C to +85°C 8-Lead SOIC_N, 7" Tape and Reel R-8 AD8278ARZ-RL −40°C to +85°C 8-Lead SOIC_N, 13" Tape and Reel R-8 AD8278BRZ −40°C to +85°C 8-Lead SOIC_N R-8 AD8278BRZ-R7 −40°C to +85°C 8-Lead SOIC_N, 7" Tape and Reel R-8 AD8278BRZ-RL −40°C to +85°C 8-Lead SOIC_N, 13" Tape and Reel R-8 AD8278ARMZ −40°C to +85°C 8-Lead MSOP RM-8 Y21 AD8278ARMZ-R7 −40°C to +85°C 8-Lead MSOP, 7" Tape and Reel RM-8 Y21 AD8278ARMZ-RL −40°C to +85°C 8-Lead MSOP, 13" Tape and Reel RM-8 Y21 AD8278BRMZ −40°C to +85°C 8-Lead MSOP RM-8 Y22 AD8278BRMZ-R7 −40°C to +85°C 8-Lead MSOP, 7" Tape and Reel RM-8 Y22 AD8278BRMZ-RL −40°C to +85°C 8-Lead MSOP, 13" Tape and Reel RM-8 Y22 AD8279ARZ −40°C to +85°C 14-Lead SOIC_N R-14 AD8279ARZ-R7 −40°C to +85°C 14-Lead SOIC_N, 7" Tape and Reel R-14 AD8279ARZ-RL −40°C to +85°C 14-Lead SOIC_N, 13" Tape and Reel R-14 AD8279BRZ −40°C to +85°C 14-Lead SOIC_N R-14 AD8279BRZ-R7 −40°C to +85°C 14-Lead SOIC_N, 7" Tape and Reel R-14 AD8279BRZ-RL −40°C to +85°C 14-Lead SOIC_N, 13" Tape and Reel R-14

1

Z = RoHS Compliant Part.

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AD8278/AD8279

NOTES

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AD8278/AD8279

NOTES

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AD8278/AD8279

NOTES

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Datasheet AD8278, AD8279 Datasheet (ANALOG DEVICES)

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

FUNCTIONAL BLOCK DIAGRAMS

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

THERMAL RESISTANCE

MAXIMUM POWER DISSIPATION

SHORT-CIRCUIT CURRENT

ESD CAUTION

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS

THEORY OF OPERATION

CIRCUIT INFORMATION

DC Performance

AC Performance

DRIVING THE AD8278 AND AD8279

INPUT VOLTAGE RANGE

POWER SUPPLIES

APPLICATIONS INFORMATION

CONFIGURATIONS

DIFFERENTIAL OUTPUT

INSTRUMENTATION AMPLIFIER

OUTLINE DIMENSIONS

ORDERING GUIDE