ANALOG DEVICES AD629 Service Manual

High Common-Mode Voltage,

R

A

www.BDTIC.com/ADI

FEATURES

Improved replacement for: INA117P and INA117KU
±270 V common-mode voltage range
Input protection to

±500 V common mode

±500 V differential mode
Wide power supply range (±2.5 V to ±18 V)
±10 V output swing on ±12 V supply
1 mA maximum power supply current

HIGH ACCURACY DC PERFORMANCE
3 ppm maximum gain nonlinearity (AD629B)
20 μV/°C maximum offset drift (AD629A)
10 μV/°C maximum offset drift (AD629B)
10 ppm/°C maximum gain drift

EXCELLENT AC SPECIFICATIONS
77 dB minimum CMRR @ 500 Hz (AD629A)
86 dB minimum CMRR @ 500 Hz (AD629B)
500 kHz bandwidth

APPLICATIONS

High voltage current sensing
Battery cell voltage monitors
Power supply current monitors
Motor controls
Isolation

100

95

90

TIO (dB)

85

80

75

70

65

60

COMMON-MO DE REJECTIO N

55

50

20 100 1k 10k 20k

Figure 2. Common-Mode Rejection Ratio vs. Frequency

FREQUENCY ( Hz)

Difference Amplifier

AD629

FUNCTIONAL BLOCK DIAGRAM

REF(–)

–V

–IN

+IN

2

3

4

S

380kΩ

380kΩ

AD629

NC = NO CONNECT

21.1kΩ

1

GENERAL DESCRIPTION

The AD629 is a difference amplifier with a very high input,
common-mode voltage range. It is a precision device that allows
the user to accurately measure differential signals in the
presence of high common-mode voltages up to ±270 V.

The AD629 can replace costly isolation amplifiers in

pplications that do not require galvanic isolation. The device

a
operates over a ±270 V common-mode voltage range and has
inputs that are protected from common-mode or differential
mode transients up to ±500 V.

The AD629 has low offset, low offset drift, low gain error drift,

w common-mode rejection drift, and excellent CMRR over a

lo
wide frequency range.

The AD629 is available in low cost, 8-lead PDIP and 8-lead
SO

IC packages. For all packages and grades, performance is
guaranteed over the industrial temperature range of −40°C to
+85°C.

2mV/DIV

OUTPUT ERROR (2mV/DIV)

00783-002

–240 240120–120 0

Figure 3. Error Voltage vs. Input Common-Mode Voltage

COMMON-MODE VOLTAGE (V)

380kΩ

20kΩ

Figure 1.

NC

8

7

+V

6

OUTPUT

5

REF(+)

60V/DIV

S

0783-001

00783-003

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.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©1999-2007 Analog Devices, Inc. All rights reserved.

AD629

www.BDTIC.com/ADI

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications....................................................................................... 1

Functional Block Diagram .............................................................. 1

General Description......................................................................... 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 4

ESD Caution.................................................................................. 4

Typical Performance Characteristics ............................................. 5

Theory of Operation ........................................................................ 9

Applications..................................................................................... 10

REVISION HISTORY

3/07—Rev. A to Rev. B

Updated Format and Layout .............................................Universal

Changes to Ordering Guide.......................................................... 15

3/00—Rev. 0 to Rev. A

10/99—Revision 0: Initial Version

Basic Connections...................................................................... 10

Single-Supply Operation ........................................................... 10

System-Level Decoupling and Grounding.............................. 10

Using a Large Sense Resistor..................................................... 11

Output Filtering.......................................................................... 11

Output Current and Buffering.................................................. 12

A Gain of 19 Differential Amplifier......................................... 12

Error Budget Analysis Example 1 ............................................ 12

Error Budget Analysis Example 2 ............................................ 13

Outline Dimensions ....................................................................... 14

Ordering Guide............................................................................... 15

Rev. B | Page 2 of 16

AD629

www.BDTIC.com/ADI

SPECIFICATIONS

TA = 25°C, VS = ±15 V, unless otherwise noted.

Table 1.

AD629A AD629B

Parameter Condition Min Typ Max Min Typ Max Unit

GAIN V

= ±10 V, RL = 2 kΩ

OUT

Nominal Gain 1 1 V/V
Gain Error 0.01 0.05 0.01 0.03 %
Gain Nonlinearity 4 10 4 10 ppm
R
Gain vs. Temperature TA = T

= 10 kΩ 1 1 3 ppm

L

to T

MIN

3 10 3 10 ppm/°C

MAX

OFFSET VOLTAGE

Offset Voltage 0.2 1 0.1 0.5 mV
V
vs. Temperature TA = T

= ±5 V 1 mV

S

to T

MIN

6 20 3 10 μV/°C

MAX

vs. Supply (PSRR) VS = ±5 V to ± 15 V 84 100 90 110 dB

INPUT

Common-Mode Rejection Ratio VCM = ±250 V dc 77 88 86 96 dB
T
V
V

= T

to T

A

MIN

= 500 V p-p, dc to 500 Hz 77 86 dB

CM

= 500 V p-p, dc to 1 kHz 88 90 dB

CM

73 82 dB

MAX

Operating Voltage Range Common mode ±270 ±270 V
Differential ±13 ±13 V

Input Operating Impedance Common mode 200 200 kΩ
Differential 800 800 kΩ
OUTPUT

Operating Voltage Range RL = 10 kΩ ±13 ±13 V

R

V

= 2 kΩ ±12.5 ±12.5 V

L

= ±12 V, RL = 2 kΩ ±10 ±10 V

S

Output Short-Circuit Current ±25 ±25 mA

Capacitive Load Stable operation 1000 1000 pF
DYNAMIC RESPONSE

Small Signal –3 dB Bandwidth 500 500 kHz

Slew Rate 1.7 2.1 1.7 2.1 V/μs

Full Power Bandwidth V

Settling Time 0.01%, V

0.1%, V

0.01%, VCM = 10 V step, V

= 20 V p-p 28 28 kHz

OUT

= 10 V step 15 15 μs

OUT

= 10 V step 12 12 μs

OUT

= 0 V 5 5 μs

DIFF

OUTPUT NOISE VOLTAGE

0.01 Hz to 10 Hz 15 15 μV p-p

Spectral Density, ≥100 Hz

1

550 550 nV/√Hz

POWER SUPPLY

Operating Voltage Range ±2.5 ±18 ±2.5 ±18 V

Quiescent Current V
T

= 0 V 0.9 1 0.9 1 mA

OUT

MIN

to T

MAX

1.2 1.2 mA

TEMPERATURE RANGE

For Specified Performance TA = T

1

See Figure 19.

MIN

to T

MAX

−40 +85 −40 +85 °C

Rev. B | Page 3 of 16

AD629

A

www.BDTIC.com/ADI

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Supply Voltage, V
Internal Power Dissipation

8-Lead PDIP (N) See Figure 4

8-Lead SOIC (R) See Figure 4
Input Voltage Range, Continuous ±300 V
Common-Mode and Differential, 10 sec ±500 V
Output Short-Circuit Duration Indefinite
Pin 1 and Pin 5 –VS − 0.3 V to +VS + 0.3 V
Maximum Junction Temperature 150°C
Operating Temperature Range −55°C to +125°C
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering 60 sec) 300°C

1

Specification is for device in free air:

8-Lead PDIP, θJA = 100°C/W;
8-Lead SOIC, θJA = 155°C/W.

S

1

±18 V

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.

Figure 4. Maximum Power Dissipation vs. Temperature for SOIC and PDIP

2.0

8-LEAD PDIP

1.5

TION (W)

1.0

8-LEAD SOI C

0.5

MAXIMUM POWER DISSIP

0

–50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90

AMBIENT TEMPERATURE (°C)

TJ = 150°C

00783-004

ESD CAUTION

Rev. B | Page 4 of 16

AD629

R

A

www.BDTIC.com/ADI

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C, VS = ±15 V, unless otherwise noted.

100

90

80

TIO (dB)

70

60

50

40

30

20

10

COMMON-M ODE REJECTI ON

0

100 1k 10k 100k 1M 10M

FREQUENCY ( Hz)

Figure 5. Common-Mode Rejection Ratio vs. Frequency

00783-006

400

360

320

280

240

200

160

120

80

COMMON-MODE VOLTAGE (±V)

40

0

02 6 104 8 12 14 1816 20

TA = +85°C

POWER SUPPLY VOLTAGE (±V)

TA = +25°C

TA = –40°C

Figure 8. Common-Mode Operating Range vs. Power Supply Voltage

00783-009

2mV/DIV

VS = ±18V

VS = ±15V

VS = ±12V

OUTPUT ERROR (2mV/DIV)

VS = ±10V

–20 –16 –8 –4 0 4 8 12 16–12 20

Figure 6. Typical Gain Error Normalized @ V

Operating Range vs. Supply Voltage, R

VS = ±18V

VS = ±15V

VS = ±12V

OUTPUT ERROR (2mV/DIV)

V

(V)

OUT

= 0 V and Output Voltage

OUT

= 10 kΩ (Curves Offset for Clarity)

L

RL = 10kΩ

4V/DIV

RL = 1kΩ

RL = 2kΩ

VS = ±18V

VS = ±15V

VS = ±12V

OUTPUT ERROR (2mV/DIV)

VS = ±10V

00783-007

–20 –16 –8 –4 0 4 8 12 16–12 20

Figure 9. Typical Gain Error Normalized @ V

Operating Range vs. Supply Voltage, R

VS = ±5V, RL = 10kΩ

VS = ±5V, RL = 2kΩ

VS = ±5V, RL = 1kΩ

OUTPUT ERROR (2mV/DIV)

V

(V)

OUT

= 0 V and Output Voltage

OUT

= 2 kΩ (Curves Offset for Clarity)

L

4V/DIV

00783-010

VS = ±10V

–20 –16 –8 –4 0 4 8 12 16–12 20

Figure 7. Typical Gain Error Normalized @ V

Operating Range vs. Supply Voltage, R

V

(V)

OUT

= 0 V and Output Voltage

OUT

= 1 kΩ (Curves Offset for Clarity)

L

4V/DIV

00783-008

Figure 10. Typical Gain Error Normalized @ V

VS = ±2.5V, RL = 1kΩ

–20 –16 –8 –4 0 4 8 12 16–12 20

Operating Range vs. Supply Voltage (Curves Offset for Clarity)

Rev. B | Page 5 of 16

1V/DIV

00783-011

V

(V)

OUT

= 0 V and Output Voltage

OUT