Datasheet

ManualsBrandsANALOG DEVICES ManualsLinear ICsLinear IC - Op-amp, differential amplifier Differential PDIP 8

High Common-Mode Voltage,

Difference Amplifier

AD629

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 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 www.analog.com

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

FUNCTIONAL BLOCK DIAGRAM

21.1kΩ

380kΩ

20kΩ

REF(–)

–IN

+IN

–V

OUTPUT

REF(+)

AD629

NC = NO CONNECT

0783-001

Figure 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

applications that do not require galvanic isolation. The device

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,

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

wide frequency range.

The AD629 is available in die and packaged form featuring

8-lead PDIP and 8-lead SOIC packages. For all packages

(including die) and grades, performance is guaranteed over

the industrial temperature range of −40°C to +85°C.

FREQUENCY (Hz)

COMMON-MODE REJECTION

TIO (dB)

100

20 100 1k 10k 20k

00783-002

Figure 2. Common-Mode Rejection Ratio vs. Frequency

COMMON-MODE VOLTAGE (V)

OUTPUT ERROR (2mV/DIV)

–240 240120–120 0

00783-003

2mV/DIV

60V/DIV

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

Summary of content (16 pages)

PAGE 1
High Common-Mode Voltage, Difference Amplifier AD629 FUNCTIONAL BLOCK DIAGRAM 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 REF(–) 1 –IN 2 +IN 3 –VS 4 380kΩ 21.1kΩ 380kΩ 380kΩ 20kΩ AD629 8 NC 7 +VS 6 OUTPUT 5 REF(+) 00783-001 FEATURES NC = NO CONNECT Figure 1.
PAGE 2
AD629 TABLE OF CONTENTS Features .............................................................................................. 1 Basic Connections...................................................................... 11 Applications....................................................................................... 1 Single-Supply Operation ........................................................... 11 Functional Block Diagram ..............................................................
PAGE 3
AD629 SPECIFICATIONS TA = 25°C, VS = ±15 V, unless otherwise noted. Table 1. Parameter GAIN Nominal Gain Gain Error Gain Nonlinearity Gain vs. Temperature OFFSET VOLTAGE Offset Voltage vs. Temperature vs. Supply (PSRR) INPUT Common-Mode Rejection Ratio Operating Voltage Range Input Operating Impedance OUTPUT Operating Voltage Range Output Short-Circuit Current Capacitive Load DYNAMIC RESPONSE Small Signal –3 dB Bandwidth Slew Rate Full Power Bandwidth Settling Time OUTPUT NOISE VOLTAGE 0.
PAGE 4
AD629 ABSOLUTE MAXIMUM RATINGS Table 2. 1a 1 Rating ±18 V 2 7 See Figure 4 See Figure 4 ±300 V ±500 V Indefinite –VS − 0.3 V to +VS + 0.3 V 150°C −55°C to +125°C −65°C to +150°C 300°C Y 3 4 6b 6a 5a 5b X Specification is for device in free air: 8-Lead PDIP, θJA = 100°C/W; 8-Lead SOIC, θJA = 155°C/W. DIE SIZE: 1655µm (X) by 2465µm (Y) Figure 5. Metallization Photograph Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device.
PAGE 5
AD629 REF(–) 1 8 NC –IN 2 AD629 7 +VS +IN 3 TOP VIEW (Not to Scale) 6 OUTPUT 5 REF(+) –VS 4 NC = NO CONNECT Figure 6. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 2 3 4 5 6 7 8 Mnemonic REF(−) −IN +IN −VS REF(+) OUTPUT +VS NC Description Negative Reference Voltage Input. Inverting Input. Noninverting Input. Negative Supply Voltage. Positive Reference Voltage Input. Output. Positive Supply Voltage. No Connect. Do not connect to this pin. Rev.
PAGE 6
AD629 TYPICAL PERFORMANCE CHARACTERISTICS 100 400 90 360 80 320 COMMON-MODE VOLTAGE (±V) 60 50 40 30 10 0 100 1k 10k 100k FREQUENCY (Hz) 1M 120 80 0 10M 2 4 6 8 10 12 14 16 POWER SUPPLY VOLTAGE (±V) 18 20 RL = 2kΩ VS = ±18V OUTPUT ERROR (2mV/DIV) VS = ±15V 4V/DIV VS = ±10V –8 –4 0 4 VOUT (V) 8 12 16 VS = ±15V VS = ±12V 00783-007 VS = ±12V –12 0 Figure 10. Common-Mode Operating Range vs.
PAGE 7
AD629 20µV/DIV 40µV/DIV VS = ±15V RL = 2kΩ 2.5V/DIV –10 –5 0 VOUT (V) 5 00783-015 00783-012 ERROR (2ppm/DIV) ERROR (0.8ppm/DIV) VS = ±15V RL = 10kΩ 2V/DIV 10 –10 Figure 13. Gain Nonlinearity; VS = ±15 V, RL = 10 kΩ –8 –6 –4 –2 0 2 VOUT (V) 4 6 8 10 Figure 16. Gain Nonlinearity; VS = ±15 V, RL = 2kΩ 14.0 –40°C VS = ±12V RL = 10kΩ 13.0 –40°C ERROR (1ppm/DIV) OUTPUT VOLTAGE (V) 12.0 11.0 VS= ±15V –10 –8 –6 –4 –2 0 2 VOUT (V) 4 6 8 9.0 –11.5 –12.0 –40°C 00783-013 –13.
PAGE 8
AD629 4.5 +85°C –40°C 3.5 +85°C 1.5 0.5 VS= ±5V +25°C +85°C –2.0 –2.5 –40°C –3.0 –4.0 +85°C +25°C 0 2 4 6 8 10 12 14 OUTPUT CURRENT (mA) 16 18 25mV/DIV Figure 19. Output Voltage Operating Range vs. Output Current; VS = ±5 V 110 100 G = +1 RL = 2kΩ CL = 1000pF –VS 90 80 70 60 50 30 1.0 10 100 FREQUENCY (Hz) 1k 25mV/DIV 4µs/DIV 10k Figure 20. Power Supply Rejection Ratio vs. Frequency 00783-022 40 0.1 Figure 23. Small Signal Pulse Response 5.0 4.
PAGE 9
AD629 5V/DIV 5V/DIV 0V +10V VOUT VOUT –10V OUTPUT ERROR OUTPUT ERROR 1mV/DIV 10µs/DIV 00783-024 1mV = 0.01% 1mV/DIV Figure 25. Settling Time to 0.01%, for 0 V to 10 V Output Step; G = −1, RL = 2 kΩ 300 200 150 100 150 100 0 150 –900 –600 –300 0 300 OFFSET VOLTAGE (µV) 600 900 Figure 29. Typical Distribution of Offset Voltage; Package Option N-8 400 400 N = 2180 n ≈ 200 PCS. FROM 10 ASSEMBLY LOTS 350 N = 2180 n ≈ 200 PCS.
PAGE 10
AD629 THEORY OF OPERATION To achieve high common-mode voltage range, an internal resistor divider (Pin 3 or Pin 5) attenuates the noninverting signal by a factor of 20. Other internal resistors (Pin 1, Pin 2, and the feedback resistor) restore the gain to provide a differential gain of unity. The complete transfer function equals To reduce output drift, the op amp uses super beta transistors in its input stage.
PAGE 11
AD629 APPLICATIONS BASIC CONNECTIONS REF (–) 1 +VS REF (–) 1 –IN RSHUNT 2 +IN 3 –VS (SEE TEXT) AD629 380kΩ 380kΩ +3V TO +18V 8 380kΩ 7 NC +VS 6 20kΩ 4 5 0.1µF (SEE TEXT) VOUT = ISHUNT × RSHUNT REF (+) 0.1µF NC = NO CONNECT –VS –3V TO –18V 00783-030 ISHUNT 21.1kΩ –IN ISHUNT RSHUNT 2 +IN 3 AD629 380kΩ 380kΩ VX 380kΩ VY –VS +VS 8 7 NC +VS 0.
PAGE 12
AD629 Table 5 shows some sample error voltages generated by a common-mode voltage of 200 V dc with shunt resistors from 20 Ω to 2000 Ω. Assuming that the shunt resistor is selected to use the full ±10 V output swing of the AD629, the error voltage becomes quite significant as RSHUNT increases. DIGITAL POWER SUPPLY GND +5V 0.1µF 0.1µF 7 –IN 2 AD629 OUTPUT 6 REF(–) REF(+) 1 14 VDD AGND DGND +VS –VS 3 6 4 VIN1 3 VIN2 AD7892-2 Table 5.
PAGE 13
AD629 OUTPUT CURRENT AND BUFFERING ERROR BUDGET ANALYSIS EXAMPLE 1 The AD629 is designed to drive loads of 2 kΩ to within 2 V of the rails but can deliver higher output currents at lower output voltages (see Figure 17). If higher output current is required, the output of the AD629 should be buffered with a precision op amp, such as the OP113, as shown in Figure 38. This op amp can swing to within 1 V of either rail while driving a load as small as 600 Ω.
PAGE 14
AD629 ERROR BUDGET ANALYSIS EXAMPLE 2 OUTPUT CURRENT REF (–) 10 AMPS ±100V AC CM TO GROUND 1 –IN 2 21.1kΩ AD629 380kΩ 380kΩ 8 NC +VS 7 0.1µF 1Ω SHUNT +IN 3 60Hz POWER LINE 380kΩ 6 20kΩ –VS 4 5 VOUT REF (+) 00783-039 This application is similar to the previous example except that the sensed load current is from an amplifier with an ac common-mode component of ±100 V (frequency = 500 Hz) present on the shunt (see Figure 41). All other conditions are the same as before.
PAGE 15
AD629 OUTLINE DIMENSIONS 0.400 (10.16) 0.365 (9.27) 0.355 (9.02) 8 5 1 4 0.280 (7.11) 0.250 (6.35) 0.240 (6.10) 0.100 (2.54) BSC 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.060 (1.52) MAX 0.210 (5.33) MAX 0.015 (0.38) MIN 0.150 (3.81) 0.130 (3.30) 0.115 (2.92) SEATING PLANE 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) 0.195 (4.95) 0.130 (3.30) 0.115 (2.92) 0.015 (0.38) GAUGE PLANE 0.430 (10.92) MAX 0.005 (0.13) MIN 0.014 (0.36) 0.010 (0.25) 0.008 (0.20) 0.070 (1.78) 0.060 (1.52) 0.045 (1.
PAGE 16
AD629 ORDERING GUIDE Model 1 AD629AN AD629ANZ AD629AR AD629AR-REEL AD629AR-REEL7 AD629ARZ AD629ARZ-RL AD629ARZ-R7 AD629BNZ AD629BR AD629BR-REEL AD629BR-REEL7 AD629BRZ AD629BRZ-RL AD629BRZ-R7 AD629AC-WP 1 Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C Package Description 8-Lead PDIP 8-Lead PDIP 8-Le