ANALOG DEVICES AD8206 Service Manual

Single-Supply, 42 V System

FEATURES

Ideal for current shunt applications High common-mode voltage range
−2 V to +65 V operating
−25 V to +75 V survival Gain = 20 Wide operating temperature range
8-lead SOIC: −40°C to +125°C Bidirectional operation Qualified for automotive applications

EXCELLENT AC AND DC PERFORMANCE

15 μV/°C offset drift 30 ppm/°C gain drift 80 dB CMRR dc to 20 kHz

APPLICATIONS

High-side current sensing in
Motor controls
Transmission controls
Diesel-injection controls
Engine management
Suspension controls
Vehicle dynamic controls
DC-to-dc converters
Difference Amplifier
AD8206

FUNCTIONAL BLOCK DIAGRAM

V+
6
+IN
8
1
–IN
AD8206
4
NC
2
NC = NO CONNECT
GND
Figure 1.
5
OUT
7
V
1
REF
3
V
2
REF
04953-001

GENERAL DESCRIPTION

The AD8206 is a single-supply difference amplifier for amplifying small differential voltages in the presence of large common-mode voltages. The operating input common-mode voltage range extends from −2 V to +65 V. The typical single­supply voltage is 5 V.
The AD8206 is offered in an 8-lead SOIC package and it is rated throughout the automotive temperature range of −40°C to +125°C.
Rev. A
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.
Excellent DC performance over temperature keeps errors in the measurement loop to a minimum. Offset drift is typically less than 15 μV/°C, and gain drift is typically below 30 ppm/°C.
The output offset can be adjusted from 0.08 V to 4.7 V with a 5 V supply by using the V attached to the V+ pin, and V
1 and V
REF
2 attached to the GND pin,
REF
2 pins. With V
REF
the output is set at half scale. Attaching both pins to GND causes the output to be unipolar, starting near ground. Attaching both pins to V+ causes the output to be unipolar starting near V+. Other offsets can be obtained by applying an external voltage to the V
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1 and V
REF
2 pins.
REF
REF
1
AD8206

TABLE OF CONTENTS

Features .............................................................................................. 1
Ground Referenced Output .........................................................9
Excellent AC and DC Performance ................................................ 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 4
ESD Caution .................................................................................. 4
Pin Configuration and Function Descriptions ............................. 5
Typical Performance Characteristics ............................................. 6
Theory of Operation ........................................................................ 8
Output Offset Adjustment ............................................................... 9
Unidirectional Operation ............................................................ 9

REVISION HISTORY

V+ Referenced Output .................................................................9
Bidirectional Operation ................................................................9
External Referenced Output ..................................................... 10
Splitting the Supply .................................................................... 10
Splitting an External Reference ................................................ 10
Applications ..................................................................................... 11
High-Side Current Sense with a Low-Side Switch ................. 11
High-Side Current Sense with a High-Side Switch ............... 11
Outline Dimensions ....................................................................... 12
Ordering Guide .......................................................................... 12
Automotive Products ................................................................. 12
5/10—Rev. 0 to Rev. A
Removed Die Form ............................................................ Universal
Changes to Features, General Description Sections .................... 1
Changes to Output Resistance ........................................................ 3
Changes to Table 2 ............................................................................ 4
Changes to Theory of Operation Section ...................................... 8
Changes to Ordering Guide .......................................................... 12
Added Automotive Products Section .......................................... 12
7/05—Revision 0: Initial Version
Rev. A | Page 2 of 12
AD8206

SPECIFICATIONS

TA = operating temperature range, VS = 5 V, unless otherwise noted.
Table 1.
AD8206 SOIC
Parameter Conditions
GAIN
Initial 20 V/V
Accuracy VO ≥ 0.1 V dc, 25°C ±1 % Accuracy Over Temperature Specified temperature range ±1.2 % Gain vs. Temperature 30 ppm/°C
VOLTAGE OFFSET
Offset Voltage (RTI) 25°C ±2 mV
Over Temperature (RTI) Specified temperature range ±4.5 mV
Offset Drift 15 μV/°C
INPUT
Input Impedance
Differential 400
Common Mode 200 kΩ Input Voltage Range Common mode, continuous −2 +65 V Differential1 250 mV Common-Mode Rejection 25°C, f = dc to 20 kHz2 76 86 dB
Operating temperature range, f = dc to 20 kHz
2
76 80 dB
OUTPUT
Output Voltage Range RL = 25 kΩ 0.08 4.7 V Output Resistance 2 Ω
DYNAMIC RESPONSE
Small Signal −3 dB Bandwidth 100 kHz Slew Rate 0.5 V/μs
NOISE
0.1 Hz to 10 Hz, RTI 20 μV p-p Spectral Density, 1 kHz, RTI 0.5 μV/√Hz
OFFSET ADJUSTMENT
Ratiometric Accuracy3 Divider to supplies 0.497 0.503 V/V Accuracy, RTO Voltage applied to V
1 and V
REF
2 in parallel ±2 mV/V
REF
Output Offset Adjustment Range VS = 5 V 0.08 4.7 V VREF Input Voltage Range 0.0 VS V VREF Divider Resistor Values 24 32 40
POWER SUPPLY
Operating Range 4.5 5.5 V Quiescent Current Over Temperature VO = 0.1 V dc 2 mA Power Supply Rejection Ratio 70 dB
Temperature Range
For Specified Performance Operating temperature range −40 +125 °C
1
Input voltage range = ±125 mV with half-scale offset.
2
Source imbalance <2 Ω.
3
The offset adjustment is ratiometric to the power supply when V
1 and V
REF
2 are used as a divider between the supplies.
REF
Unit Min Typ Max
Rev. A | Page 3 of 12
AD8206

ABSOLUTE MAXIMUM RATINGS

Table 2.
Parameter Rating
Supply Voltage 12.5 V Continuous Input Voltage −25 V to +75 V Input Transient Survival −30 V to +80 V Differential Input Survival −25 V to 75 V Reverse Supply Voltage 0.3 V Operating Temperature Range −40°C to +125°C Storage Temperature Range −65°C to +150°C Output Short-Circuit Duration Indefinite
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and 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.

ESD CAUTION

Rev. A | Page 4 of 12
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