AD8207 AD | Alldatasheet

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Zero-Drift, High Voltage, Bidirectional Difference Amplifier AD8207 Rev. 0 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. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 © 2010 Analog Devices, Inc. All rights reserved.

FEATURES

Ideal for current shunt applications EMI filters included 1 μV/°C maximum input offset drift High common-mode voltage range −4 V to +65 V operating (5 V supply) −4 V to +35 V operating (3.3 V supply) −25 V to +75 V survival Gain = 20 V/V 3.3 V to 5.5 V supply range Wide operating temperature range: −40°C to +125°C Bidirectional current monitoring <500 nV/°C typical offset drift <10 ppm/°C typical gain drift >90 dB CMRR dc to 10 kHz Qualified for automotive applications

APPLICATIONS

High-side current sensing in Motor control Solenoid control Engine management Electric power steering Suspension control Vehicle dynamic control DC-to-DC converters FUNCTIONAL BLOCK DIAGRAM REF +IN –IN OUT GN D VREF1 VREF2 RANGE AD8207 ZERO DRIFT 09160-001 Figure 1. GENERAL DESCRIPTION The AD8207 is a single-supply difference amplifier ideal for amplifying small differential voltages in the presence of large common-mode voltage. The operating input common-mode voltage range extends from −4 V to +65 V with a 5 V supply. The AD8207 works with a single-supply voltage of 3.3 V to 5 V , and is ideally suited to withstand large input PWM common- mode voltages, typical in solenoid and motor control applications. The AD8207 is available in an 8-lead SOIC package. Excellent dc performance over temperature keeps errors in the mea- surement loop to a minimum. Offset drift is typically less than 500 nV/°C, and gain drift is typically below 10 ppm/°C. The AD8207 is ideal for bidirectional current sensing applications. It features two reference pins,V REF1 and VREF2, that allow the user to easily offset the output of the device to any voltage within the supply range. With V REF1 attached to the V+ pin and VREF2 attached to the GND pin, 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+ ca uses the output to be unipolar starting near V+. Other output offsets are achieved by applying an external low impedance voltage to the VREF1 and VREF2 pins.

Rev. 0 | Page 2 of 16 TABLE OF CONTENTS

REVISION HISTORY

7/10—Revision 0: Initial Version

Rev. 0 | Page 3 of 16 SPECIFICATIONS TOPR = −40°C to +125°C, V+ = 5 V or 3.3 V , unless otherwise noted. Table 1. Parameter Min Typ Max Unit Test Conditions/Comments GAIN Initial 20 V/V Accuracy over Temperature −0.3 +0.3 % TOPR Gain vs. Temperature −15 0 ppm/°C TOPR VOLTAGE OFFSET Offset Voltage (RTI)1 ±100 μV 25°C Over Temperature (RTI)1 ±400 μV TOPR Offset Drift −1 +1 μV/°C TOPR INPUT Input Impedance Differential 240 kΩ Common Mode 126 kΩ Input Voltage Range −4 +65 V Common mode, continuous, V+ = 5 V, TOPR −4 +35 V Common mode continuous, V+ = 3.3 V, TOPR 250 mV Differential2, V+ = 5 V Common-Mode Rejection (CMRR) 80 90 dB TOPR, f = dc to 20 kHz OUTPUT Output Voltage Range 0.02 V+ − 0.05 V RL = 25 kΩ, TOPR Output Resistance 2 Ω DYNAMIC RESPONSE Small-Signal −3 dB Bandwidth 150 kHz TOPR Slew Rate 1 V/μs NOISE

0.1 Hz to 10 Hz, (RTI)1 20 μV p-p

Spectral Density, 1 kHz, (RTI)1 0.6 μV/√Hz OFFSET ADJUSTMENT Ratiometric Accuracy3 0.497 0.503 V/V Divider to supplies, TOPR Accuracy (RTO)4 ±3 mV/V Voltage applied to VREF1 and VREF2 in parallel, TOPR Output Offset Adjustment Range 0.02 V+ − 0.05 V TOPR VREF Input Voltage Range5 0.0 V+ V VREF Divider Resistor Values 100 kΩ POWER SUPPLY Operating Range 4.5 5.5 V RANGE (Pin 4) connected to GND6 3.3 4.5 V RANGE (Pin 4) connected to V+7 Quiescent Current over Temperature 2.5 mA VO = 0.1 V dc Power Supply Rejection Ratio (PSRR) 80 dB TEMPERATURE RANGE For Specified Performance −40 +125 °C 1 RTI = referred to input. 2 Input voltage range = ±125 mV with half-scale offset. The input differential range also depends on the supply voltage. The maximum input differential range can be calculated by V+/20. 3 The offset adjustment is ratiometric to the power supply when VREF1 and VREF2 are used as a divider between the supplies. 4 RTO = referred to output. 5 The reference pins should be driven with a low impedance voltage source to maintain the specified accuracy of the AD8207. 6 With a 4.5 V to 5.5 V supply, the RANGE pin should be tied low. In this mode, the common-mode range of the AD8207 is −4 V to +65 V. user can tie RANGE high or low depending on the common-mode range needed in the application.

Rev. 0 | Page 4 of 16 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 Voltage −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

Figure 2. Pin Configuration Table 3. Pin Function Descriptions

changing common-mode voltage. supply range of the amplifier, in this case with a ratio of 20/1. is set to 400 V/V to provide a total system gain of 20 V/V . changing external common-mode variations. width, which is typically rated at 150 kHz. the pins are used to divide the supply, the gain is 0.5 V/V . the lowest offset and offset drift performance on the market. Figure 25. Simplified Schematic

REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure 37. 8-Lead Standard Small Outline Package [SOIC_N] 2 W = Qualified for Automotive Applications. obtain the specific Automotive Reliability reports for these models. registered trademarks are the prop erty of their respective owners.