AD8209WBRMZ

High Voltage, Precision Difference Amplifier AD8209 Data Sheet FUNCTIONAL BLOCK DIAGRAM ±8000 V HBM ESD for shunt-based applications AEC-Q100 qualified EMI filters included High common-mode voltage range −2 V to +45 V operating −24 V to +80 V survival Buffered output voltage Gain = 14 V/V Low-pass filter (single-pole or two-pole) Wide operating temperature range −40°C to +125°C for WB grade −40°C to +150°C for WH grade Excellent ac and dc performance ±1 mV voltage offset −5 ppm/°C typical gain drift 80 dB CMRR minimum dc to 10 kHz Qualified for automotive applications VS A1 EMI FILTER IN+ EMI FILTER IN– EMI FILTER A2 AD8209 + G=2 – + G=7 – GND OUT 08461-001 FEATURES Figure 1. APPLICATIONS High-side current sensing Motor controls Solenoid controls Power management Low-side current sensing Diagnostic protection GENERAL DESCRIPTION The AD8209 is a single-supply difference amplifier ideal for amplifying and low-pass filtering small differential voltages in the presence of a large common-mode voltage. The input commonmode voltage range extends from −2 V to +45 V at a single +5 V supply. The AD8209 is qualified per AEC-Q100 specifications. The amplifier offers enhanced input overvoltage and ESD protection, and includes EMI filtering. performance, minimizing errors in the application. Typical offset and gain drift in the MSOP package are less than 5 µV/°C and 10 ppm/°C, respectively. The device also delivers a minimum CMRR of 80 dB from dc to 10 kHz. The AD8209 features an externally accessible 100 kΩ resistor at the output of the preamplifier (A1), which can be used for lowpass filtering and for establishing gains other than 14. Automotive applications demand robust, precision components for improved system control. The AD8209 provides excellent ac and dc Rev. C Document Feedback 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 ©2009–2016 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com AD8209 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1  High-Side Current Sensing with a Low-Side Switch ............. 12  Applications ....................................................................................... 1  High-Rail Current Sensing ....................................................... 12  Functional Block Diagram .............................................................. 1  Low-Side Current Sensing ........................................................ 12  General Description ......................................................................... 1  Gain Adjustment ........................................................................ 13  Revision History ............................................................................... 2  Gain Trim .................................................................................... 14  Specifications..................................................................................... 3  Low-Pass Filtering ...................................................................... 14  Absolute Maximum Ratings............................................................ 5  High Line Current Sensing with LPF and Gain Adjustment ......15  ESD Caution .................................................................................. 5  Outline Dimensions ....................................................................... 16  Pin Configuration and Function Descriptions ............................. 6  Ordering Guide .......................................................................... 16  Typical Performance Characteristics ............................................. 7  Automotive Products ................................................................. 16  Theory of Operation ...................................................................... 11  Applications Information .............................................................. 12  REVISION HISTORY 12/2016—Rev. B to Rev. C 2/2013—Rev. 0 to Rev. A Changes to Figure 27 .......................................................................12 Change to Features ............................................................................ 1 Changes to Figure 3 and Table 3 ...................................................... 5 Change to Ordering Guide ............................................................. 15 Added Automotive Products Section ........................................... 15 10/2013—Rev. A to Rev. B Changes to Features Section............................................................ 1 Changes to Table Summary Statement and Table 1 ..................... 3 Changes to Table 2 ............................................................................ 5 Changes to Gains Greater than 14 Section and Figure 30 ........ 13 Changes to Ordering Guide .......................................................... 16 10/2009—Revision 0: Initial Version Rev. C | Page 2 of 16 Data Sheet AD8209 SPECIFICATIONS TOPR = −40°C to +125°C for AD8209WBRM grade, TOPR = −40°C to +150°C for AD8209WHRM grade, TA = 25°C, VS = 5 V, RL = 25 kΩ (RL is the output load resistor), unless otherwise noted. Table 1. Parameter SYSTEM GAIN Initial Error vs. Temperature AD8209WBRM AD8209WHRM Gain Drift VOLTAGE OFFSET Initial Input Offset (Referred to Input [RTI]) Input Offset (RTI) Over Temperature Voltage Offset vs. Temperature INPUT Input Impedance Differential Common Mode VCM (Continuous) CMRR 2 PREAMPLIFIER (A1) Gain Gain Error AD8209WBRM AD8209WHRM Output Voltage Range Output Resistance OUTPUT BUFFER (A2) Gain Gain Error AD8209WBRM AD8209WHRM Output Voltage Range 4, 5 AD8209WBRM AD8209WHRM Output Voltage Range 6 AD8209WBRM AD8209WHRM Input Bias Current Output Resistance DYNAMIC RESPONSE System Bandwidth Slew Rate NOISE 0.1 Hz to 10 Hz Spectral Density, 1 kHz (RTI) Test Conditions 1 Min Typ Max 14 0.075 V ≤ VOUT ≤ (VS − 0.1 V), dc, TOPR 0.100 V ≤ VOUT ≤ (VS − 0.12 V), dc, TOPR TOPR Unit V/V 0 ±0.3 ±0.3 −20 % % ppm/°C VCM = 0.15 V, TA VCM = 0 V, TOPR VCM = 0 V, TOPR −20 ±2 ±4 +20 mV mV µV/°C 440 220 +45 VCM = −2 V to +45 V, dc f = dc to 10 kHz, 3 TOPR 360 180 −2 80 80 kΩ kΩ V dB dB 400 200 100 7 0.0375 V ≤ VOUT ≤ (VS − 0.1 V), dc, TOPR 0.050 V ≤ VOUT ≤ (VS − 0.1 V), dc, TOPR AD8209WBRM AD8209WHRM −0.3 −0.3 0.0375 0.05 97 100 V/V +0.3 +0.3 VS − 0.1 VS − 0.1 103 2 0.075 V ≤ VOUT ≤ (VS − 0.1 V), dc, TOPR 0.1 V ≤ VOUT ≤ (VS − 0.12 V), dc, TOPR RL = 25 kΩ, differential Input (V) = 0 V, TOPR Pin 3 (A1 output) driving Pin 4 (A2 input) % % V V kΩ V/V −0.3 −0.3 +0.3 +0.3 % % 0.075 0.1 VS − 0.1 VS − 0.12 V V 0.075 0.1 VS − 0.1 VS − 0.12 50 Pin 4 (A2 input) driven with external source TOPR RL = 1 kΩ, frequency = dc 2 V V nA Ω VIN = 0.01 V p-p, VOUT = 0.14 V p-p VIN = 0.28 V, VOUT = 4 V step 80 1 kHz V/µs 20 500 µV p-p nV/√Hz Rev. C | Page 3 of 16 AD8209 Parameter POWER SUPPLY Operating Range Quiescent Current Quiescent Current vs. Temperature AD8209WBRM AD8209WHRM PSRR TEMPERATURE RANGE AD8209WBRM AD8209WHRM Data Sheet Test Conditions 1 Min Typ 4.5 Typical, TA VOUT = 0.1 V dc, VS = 5 V, TOPR VS = 4.5 V to 5.5 V, TOPR For Specified Performance at TOPR Max Unit 5.5 V mA 2.7 3.0 mA mA dB +125 +150 °C °C 1.6 66 −40 −40 80 VCM = input common-mode voltage. Source imbalance < 2 Ω. 3 The AD8209 preamplifier exceeds 80 dB CMRR at 10 kHz. However, because the output is available only by way of the 100 kΩ resistor, even a small amount of pin-topin capacitance between the IN pins and the A1 and A2 pins might couple an input common-mode signal larger than the greatly attenuated preamplifier output. The effect of pin-to-pin coupling can be neglected in all applications by using a filter capacitor from Pin 3 to GND. 4 The output voltage range of the AD8209 varies depending on the load resistance and temperature. For additional information on this specification, refer to Figure 12 and Figure 13. 5 The output voltage range of A2 assumes that Pin 3 (A1 output) and Pin 4 (A2 input) are shorted together. A 25 kΩ load resistor is used for testing. 6 The output voltage range of A2 assumes Pin 4 (A2 input) is driven with an external voltage source. A 25 kΩ load resistor is used for testing. 1 2 Rev. C | Page 4 of 16 Data Sheet AD8209 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Supply Voltage Continuous Input Voltage (Common Mode) Differential Input Voltage Reversed Supply Voltage Protection ESD Human Body Model for Shunt-Based Applications1 Operating Temperature Range AD8209WBRM AD8209WHRM Storage Temperature Range Output Short-Circuit Duration Lead Temperature Range (Soldering 10 sec) 1 Rating 12 V −24 V to +80 V ±12 V 0.3 V ±8000 V −40°C to +125°C −40°C to +150°C −65°C to +150°C Indefinite 300°C Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability. ESD CAUTION Shunt-based applications have a low impedance shunt resistor between +IN and –IN. See Figure 24 for an example of a shunt-based application. Rev. C | Page 5 of 16 AD8209 Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 1 8 2 7 2 A1 3 AD8209 TOP VIEW (Not to Scale) A2 4 +IN 7 VS 6 NC 5 OUT NC = NO CONNECT 3 4 5 08461-003 GND 2 8 08461-002 –IN 1 Figure 2. Pin Configuration Figure 3. Metallization Photograph Table 3. Pin Function Descriptions Pin No. 1 2 2 3 4 5 6 7 8 Mnemonic −IN GND GND A1 A2 OUT NC VS +IN Coordinates X Y −322 +563 −321 +208 −327 +339 −321 −51 −321 −214 +321 −388 +322 +322 +363 +561 Description Inverting Input Ground Ground Preamplifier (A1) Output Buffer (A2) Input Buffer (A2) Output No Connect Supply Noninverting Input Rev. C | Page 6 of 16 Data Sheet AD8209 TYPICAL PERFORMANCE CHARACTERISTICS 0.70 1500 0.55 1250 0.40 1000 0.25 750 GAIN ERROR (ppm) 0.10 –0.05 –0.20 –0.35 500 250 0 –250 –0.50 –500 –0.65 08461-004 TEMPERATURE (°C) –1000 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 TEMPERATURE (°C) Figure 4. Typical Offset Drift vs. Temperature Figure 7. Typical Gain Error vs. Temperature 30 0.47 TOTAL INPUT BIAS CURRENT (mA) 25 20 15 GAIN (dB) 08461-005 –750 –0.80 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 10 5 0 –5 –10 0.42 0.37 0.32 0.27 0.22 0.17 0.12 0.07 0.02 –15 10k 100k FREQUENCY (Hz) 1M –0.03 08461-022 –20 1k –2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 INPUT COMMON-MODE (V) Figure 5. Typical Small-Signal Bandwidth 08461-006 VOSI (mV) TOPR = −40°C to +125°C, TA = 25°C, VS = 5 V, RL = 25 kΩ (RL is the output load resistor), unless otherwise noted. Figure 8. Total Input Bias Current vs. Common-Mode Voltage, with +IN and –IN Pins Connected (Shorted) –35 140 130 +125°C +25°C 110 –40°C 90 80 70 60 50 –30 –40°C –25 +25°C +125°C –20 –15 30 10 100 1k 10k 100k FREQUENCY (Hz) 1M –10 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 A2 INPUT VOLTAGE (V) 2.0 2.2 2.4 08461-007 40 08461-012 CMRR (dB) 100 A2 INPUT BIAS CURRENT (nA) 120 Figure 9. Input Bias Current of A2 vs. Input Voltage and Temperature Figure 6. Typical CMRR vs. Frequency Rev. C | Page 7 of 16 AD8209 Data Sheet 2.0 11.5 1.8 11.0 OUTPUT VOLTAGE RANGE (V) 10.5 10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 1.6 1.4 1.2 1.0 0.8 0.6 0.4 6.0 5.0 –40 –20 0 20 40 60 80 TEMPERATURE (°C) 100 120 140 0 Figure 10. Maximum Output Sink Current vs. Temperature 0 0.5 1.0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 2.5 3.5 4.5 5.5 6.5 7.5 8.5 OUTPUT SINK CURRENT (mA) Figure 13. Output Voltage Range from GND vs. Output Sink Current 6.3 6.0 5.8 INPUT 100mV/DIV 5.5 1 5.3 OUTPUT 5.0 4.8 500mV/DIV 4.5 2 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 08461-018 4.3 TIME (2µs/DIV) 08461-009 MAXIMUM OUTPUT SOURCE CURRENT (mA) 6.5 4.1 –40 Figure 11. Maximum Output Source Current vs. Temperature Figure 14. Rise Time 5.0 4.2 100mV/DIV 3.8 INPUT 3.4 1 3.0 500mV/DIV 2.6 2.2 OUTPUT 1.8 2 08461-017 OUTPUT VOLTAGE RANGE (V) 4.6 1.4 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 OUTPUT SOURCE CURRENT (mA) TIME (2µs/DIV) 08461-010 1.0 08461-011 0.2 5.5 08461-008 MAXIMUM OUTPUT SINK CURRENT (mA) 12.0 Figure 12. Output Voltage Range of A2 vs. Output Source Current Figure 15. Fall Time Rev. C | Page 8 of 16 Data Sheet AD8209 200mV/DIV 3 2 2V/DIV INPUT 2V/DIV 3 0.01%/DIV OUTPUT 08461-016 08461-014 2 TIME (2µs/DIV) TIME (20µs/DIV) Figure 16. Differential Overload Recovery, Rising Figure 19. Settling Time, Falling 500 +125°C +25°C –40°C 200mV/DIV 400 INPUT 300 COUNT 3 2V/DIV 2 200 OUTPUT 0 –4 TIME (2µs/DIV) –3 Figure 17. Differential Overload Recovery, Falling –2 –1 0 VOS (mV) 1 2 3 4 10 15 20 08461-019 08461-013 100 Figure 20. Offset Distribution 180 150 120 2V/DIV COUNT 2 0.01%/DIV 90 60 3 0 –20 TIME (20µs/DIV) –15 –10 –5 0 5 OFFSET DRIFT (µV/°C) Figure 21. Offset Drift Distribution Figure 18. Settling Time, Rising Rev. C | Page 9 of 16 08461-020 08461-015 30 AD8209 Data Sheet 1400 1200 800 600 400 200 0 –20 –15 –10 –5 0 5 GAIN DRIFT (ppm/°C) 10 15 20 08461-021 COUNT 1000 Figure 22. Gain Drift Distribution Rev. C | Page 10 of 16 Data Sheet AD8209 THEORY OF OPERATION The AD8209 is a single-supply difference amplifier typically used to amplify a small differential voltage in the presence of rapidly changing, high common-mode voltages. The AD8209 consists of two amplifiers (A1 and A2), a resistor network, a small voltage reference, and a bias circuit (not shown); see Figure 23. The set of input attenuators preceding A1 consist of RA, RB, and RC, which feature a combined series resistance of approximately 400 kΩ ± 20%. The purpose of these resistors is to attenuate the input voltage to match the input voltage range of A1. This balanced resistor network attenuates the common-mode signal by a ratio of 1/14. The A1 amplifier inputs are held within the power supply range, even as Pin 1 and Pin 8 exceed the supply or fall below the common (ground). A reference voltage of 350 mV biases the attenuator above ground, allowing Amplifier A1 to operate in the presence of negative common-mode voltages. The input resistor network also attenuates normal (differential) mode voltages. Therefore, A1 features a gain of 97 V/V to provide a total system gain, from ±IN to the output of A1, equal to 7 V/V, as shown in the following equation: by connecting A1 to A2 and placing a capacitor to ground (see Figure 32). The value of RF1 and RF2 is 10 kΩ, providing a gain of 2 V/V for Amplifier A2. When connecting Pin A1 and Pin A2 together, the AD8209 provides a total system gain equal to Total Gain of (A1 + A2) (V/V) = 7 (V/V) × 2 (V/V) = 14 V/V at the output of A2 (the OUT pin). The ratios of RA, RB, RC, and RF are trimmed to a high level of precision, allowing a typical CMRR value that exceeds 80 dB. This performance is accomplished by laser trimming the resistor ratio matching to better than 0.01%. –IN RA +IN VS RA – RF RB RG RC RC A2 RFILTER + + RB A1 A1 OUT A2 – RF1 RF RM RF2 A precision trimmed, 100 kΩ resistor is placed in series with the output of Amplifier A1. The user has access to this resistor via an external pin (A1). A low-pass filter can be easily implemented Rev. C | Page 11 of 16 08461-025 350mV Gain (A1) = 1/14 (V/V) × 97 (V/V) = 7 V/V GND Figure 23. Simplified Schematic AD8209 Data Sheet APPLICATIONS INFORMATION HIGH-SIDE CURRENT SENSING WITH A LOW-SIDE SWITCH HIGH-RAIL CURRENT SENSING In load control configurations for high-side current sensing with a low-side switch, the PWM-controlled switch is ground referenced. An inductive load (solenoid) connects to a power supply/battery. A resistive shunt is placed between the switch and the load (see Figure 24). An advantage of placing the shunt on the high side is that the entire current, including the recirculation current, is monitored because the shunt remains in the loop when the switch is off. In addition, shorts to ground can be detected with the shunt on the high side, enhancing the diagnostics of the control loop. In this circuit configuration, when the switch is closed, the commonmode voltage moves down to near the negative rail. When the switch is opened, the voltage reversal across the inductive load causes the common-mode voltage to be held one diode drop above the battery by the clamp diode. In the high-rail current-sensing configuration, the shunt resistor is referenced to the battery. High voltage is present at the inputs of the current-sense amplifier. When the shunt is battery referenced, the AD8209 produces a linear ground-referenced analog output. Additionally, the AD8214 can be used to provide an overcurrent detection signal in as little as 100 ns (see Figure 26). This feature is useful in high current systems where fast shutdown in overcurrent conditions is essential. OVERCURRENT DETECTION (