ANALOG DEVICES AD8211

High Voltage Current Shunt Monitor AD8211 FEATURES FUNCTIONAL BLOCK DIAGRAM V V IN+ IN– Qualified for automotive applications ±4000 V HBM ESD High common-mode voltage range −2 V to +65 V operating V+ A1 −3 V to +68 V survival Buffered output voltage PROPRIETARY Wide operating temperature range OFFSET CIRCUITRY 5-lead SOT: −40°C to +125°C Excellent ac and dc performance OUT 5 μV/°C typical offset drift G = +20 −13 ppm/°C typical gain drift AD8211 120 dB typical CMRR at dc GND Figure 1. APPLICATIONS High-side current sensing Motor controls Transmission controls Engine management Suspension controls Vehicle dynamic controls DC-to-dc converters GENERAL DESCRIPTION The AD8211 is a high voltage, precision current shunt amplifier. Special circuitry is devoted to output linearity being maintained It features a set gain of 20 V/V, with a typical ±0.35% gain error throughout the input differential voltage range of 0 mV to 250 mV, over the entire temperature range. The buffered output voltage regardless of the common-mode voltage present. The AD8211 directly interfaces with any typical converter. Excellent common- has an operating temperature range of −40°C to +125°C and is mode rejection from −2 V to +65 V is independent of the 5 V offered in a small 5-lead SOT package. supply. The AD8211 performs unidirectional current measure- ments across a shunt resistor in a variety of industrial and automotive applications, such as motor control, solenoid control, or battery management. 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 ©2007-2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 06824-001 AD8211 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 10 Applications ....................................................................................... 1 Application Notes ........................................................................... 11 Functional Block Diagram .............................................................. 1 Output Linearity ......................................................................... 11 General Description ......................................................................... 1 Applications Information .............................................................. 12 Revision History ............................................................................... 2 High-Side Current Sense with a Low-Side Switch ................. 12 Specifications ..................................................................................... 3 High-Side Current Sensing ....................................................... 12 Absolute Maximum Ratings ............................................................ 4 Low-Side Current Sensing ........................................................ 12 ESD Caution .................................................................................. 4 Outline Dimensions ....................................................................... 13 Pin Configuration and Function Descriptions ............................. 5 Ordering Guide .......................................................................... 13 Typical Performance Characteristics ............................................. 6 REVISION HISTORY 3/11—Rev. 0 to Rev. A Added Automotive Products Information ................. Throughout Changes to General Description, Gain Error Percentage ........... 1 Changes to Table 1 ............................................................................ 3 Changes to Table 2 ............................................................................ 4 Updated Outline Dimensions ....................................................... 13 Changes to Ordering Guide .......................................................... 13 7/07—Revision 0: Initial Version Rev. A | Page 2 of 16 AD8211 SPECIFICATIONS T = −40°C to +125°C, T = 25°C, V = 5 V, R = 25 kΩ (R is the output load resistor), unless otherwise noted. OPR A S L L Table 1. Y GRADE W GRADE Parameter Min Typ Max Min Typ Max Unit Conditions GAIN Initial 20 20 V/V Accuracy ±0.25 ±0.25 % V ≥ 0.1 V dc O Accuracy Over Temperature ±0.35 ±0.4 % TOPR 1 Gain vs. Temperature −13 −13 ppm/°C TOPR VOLTAGE OFFSET Offset Voltage (RTI) ±1 ±1 mV 25°C Over Temperature (RTI) ±2.2 ±2.5 mV TOPR 2 Offset Drift 5 5 μV/°C TOPR INPUT Input Impedance Differential 5 5 kΩ Common Mode 5 5 MΩ Common-mode voltage > 5 V 3.5 3.5 kΩ Common-mode voltage < 5 V Common-Mode Input Voltage −2 +65 −2 +65 V Common-mode continuous Range Differential Input Voltage Range 250 250 mV Differential input voltage Common-Mode Rejection 100 120 100 120 dB T , f = dc, V > 5 V, see OPR CM Figure 5 80 90 80 90 dB TOPR, f = dc, VCM < 5 V, see Figure 5 OUTPUT TOPR Output Voltage Range Low 0.1 0.05 0.1 0.05 V TOPR Output Voltage Range High 4.95 4.9 4.95 4.9 V Output Impedance 2 2 Ω DYNAMIC RESPONSE Small Signal −3 dB Bandwidth 500 500 kHz Slew Rate 4.5 4.5 V/μs NOISE 0.1 Hz to 10 Hz, RTI 7 7 μV p-p Spectral Density, 1 kHz, RTI 70 70 nV/√Hz POWER SUPPLY Operating Range 4.5 5.5 4.5 5.5 V 3 Quiescent Current Over Temperature 1.2 2.0 1.2 2.0 mA VCM > 5 V , see Figure 12 Power Supply Rejection Ratio 76 76 dB TEMPERATURE RANGE For Specified Performance −40 +125 −40 +125 °C 1 The mean of the gain drift distribution is typically −13 ppm/°C, with a σ = 3 ppm/°C. 2 The mean of the offset drift distribution is typically +5 μV/°C, with a σ = 3 μV/°C. 3 When the input common-mode voltage is less than 5 V, the supply current increases, which can be calculated by IS = −0.275 (VCM) + 2.5. Rev. A | Page 3 of 16 AD8211 ABSOLUTE MAXIMUM RATINGS Table 2. Stresses above those listed under Absolute Maximum Ratings Parameter Rating may cause permanent damage to the device. This is a stress Supply Voltage 12.5 V rating only; functional operation of the device at these or any Continuous Input Voltage −3 V to +68 V other conditions above those indicated in the operational Reverse Supply Voltage −0.3 V section of this specification is not implied. Exposure to absolute Differential Input Voltage ±500 mV maximum rating conditions for extended periods may affect HBM (Human Body Model) ESD Rating ±4000 V device reliability. CDM (Charged Device Model) ESD Rating ±1000 V Operating Temperature Range −40°C to +125°C ESD CAUTION Storage Temperature Range −65°C to +150°C Output Short-Circuit Duration Indefinite Rev. A | Page 4 of 16 AD8211 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS OUT 1 5 V+ AD8211 GND 2 TOP VIEW 1 2 5 1 2 5 (Not to Scale) V 3 4 V IN+ IN– NC = NO CONNECT Figure 3. Pin Configuration 3 4 3 4 Figure 2. Metallization Diagram Table 3. Pin Function Descriptions Pin No. Mnemonic X Y Description 1 OUT −277 +466 Buffered Output. 2 GND −140 +466 Ground. 3 V −228 −519 Noninverting Input. IN+ 4 V +229 −519 Inverting Input. IN− 5 V+ +264 +466 Supply. Rev. A | Page 5 of 16 06824-030 06824-002 35 AD8211 TYPICAL PERFORMANCE CHARACTERISTICS 1.2 40 1.0 30 0.8 25 0.6 20 15 0.4 10 0.2 5 0 0 –5 –0.2 –10 –0.4 –15 –0.6 –20 –25 –0.8 –30 –1.0 –35 –1.2 –40 –40 –20 0 20 40 60 80 100 120 10k 100k 1M 10M TEMPERATURE (°C) FREQUENCY (Hz) Figure 4. Typical Offset vs. Temperature Figure 7. Typical Small Signal Bandwidth (VOUT = 200 mV p-p) 140 10 9 130 COMMON-MODE VOLTAGE > 5V 8 120 7 110 6 100 5 COMMON-MODE VOLTAGE < 5V 4 90 3 80 2 70 1 60 0 10 100 1k 10k 100k 1M 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 250 FREQUNCY (Hz) DIFFERENTIAL INPUT VOLTAGE (mV) Figure 5. Typical CMRR vs. Frequency Figure 8. Total Output Error vs. Differential Input Voltage 2500 –510 –515 2000 –520 1500 –525 1000 –530 500 –535 V IN+ 0 –540 –545 –500 –550 –1000 –555 –1500 –560 V IN– –2000 –565 –2500 –570 –40 –20 0 20 40 60 80 100 120 0 25 50 75 100 125 150 175 200 225 250 TEMPERATURE (°C) DIFFERENTIAL INPUT VOLTAGE (mV) Figure 6. Typical Gain Error vs. Temperature Figure 9. Input Bias Current vs. Differential Input Voltage, VCM = 0 V Rev. A | Page 6 of 16 GAIN ERROR (PPM) CMRR (dB) V (mV) OSI 06824-114 06824-112 06824-113 INPUT BIAS CURRENT (µA) TOTAL OUTPUT ERROR (%) GAIN (dB) 06824-118 06824-107 06824-103 AD8211 110 100 100mV/DIV 90 INPUT V IN+ 80 1V/DIV 70 60 V IN– OUTPUT 50 40 0 25 50 75 100 125 150 175 200 225 250 TIME (500ns/DIV) DIFFERENTIAL INPUT VOLTAGE (mV) Figure 10. Input Bias Current vs. Differential Input Voltage, Figure 13. Fall Time V = 5 V CM 0.8 0.4 INPUT 0 100mV/DIV OUTPUT –0.4 –0.8 1V/DIV –1.2 –1.6 –2.0 –2.4 –5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 TIME (500ns/DIV) INPUT COMMON-MODE VOLTAGE (V) Figure 11. Input Bias Current vs. Input Common-Mode Voltage Figure 14. Rise Time 4.0 200mV/DIV 3.5 3.0 INPUT 2.5 2V/DIV 2.0 1.5 OUTPUT 1.0 –4 –2 0 2 4 6 8 65 TIME (1µs/DIV) COMMON-MODE VOLTAGE (V) Figure 12. Supply Current vs. Common-Mode Voltage Figure 15. Differential Overload Recovery (Falling) Rev. A | Page 7 of 16 SUPPLY CURRENT (mA) INPUT BIAS CURRENT (mA) INPUT BIAS CURRENT (µA) 06824-101 06824-102 06824-104 06824-109 06824-111 06824-110 AD8211 12.0 11.5 INPUT 11.0 10.5 10.0 200mV/DIV 9.5 9.0 8.5 8.0 7.5 OUTPUT 7.0 6.5 2V/DIV 6.0 5.5 5.0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 TIME (1µs/DIV) TEMPERATURE (°C) Figure 16. Differential Overload Recovery (Rising) Figure 19. Maximum Output Sink Current vs. Temperature 9.0 8.5 2V/DIV 8.0 7.5 7.0 6.5 6.0 0.01/DIV 5.5 5.0 4.5 4.0 TIME 5µs/DIV) –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) Figure 20. Maximum Output Source Current vs. Temperature Figure 17. Settling Time (Falling) 5.0 4.6 4.2 2V/DIV 3.8 3.4 3.0 2.6 0.01/DIV 2.2 1.8 1.4 1.0 TIME 5µs/DIV) 0 1 2 3 4 5 6 7 8 9 OUTPUT SOURCE CURRENT (mA) Figure 21. Output Voltage Range vs. Output Source Current Figure 18. Settling Time (Rising) Rev. A | Page 8 of 16 06824-119 06824-120 06824-108 OUTPUT VOLTAGE RANGE (V) MAXIMUM OUTPUT SOURCE CURRENT (mA) MAXIMUM OUTPUT SINK CURRENT (mA) 06824-117 06824-105 06824-106 AD8211 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 OUTPUT SINK CURRENT (mA) Figure 22. Output Voltage Range from GND vs. Output Sink Current Rev. A | Page 9 of 16 OUTPUT VOLTAGE RANGE FROM GND (V) 06824-116 AD8211 THEORY OF OPERATION In typical applications, the AD8211 amplifies a small differential A load current flowing through the external shunt resistor input voltage generated by the load current flowing through produces a voltage at the input terminals of the AD8211. The a shunt resistor. The AD8211 rejects high common-mode input terminals are connected to Amplifier A1 by Resistor R voltages (up to 65 V) and provides a ground-referenced, and Resistor R1. The inverting terminal, which has very high buffered output that interfaces with an analog-to-digital converter input impedance is held to (ADC). Figure 23 shows a simplified schematic of the AD8211. (V ) − (I × R ) CM SHUNT SHUNT I SHUNT because negligible current flows through Resistor R. Amplifier A1 forces the noninverting input to the same potential. Therefore, R SHUNT the current that flows through Resistor R1, is equal to I IN R1 R IIN = (ISHUNT × RSHUNT)/R1 This current (IIN) is converted back to a voltage via ROUT. The V+ A1 output buffer amplifier has a gain of 20 V/V and offers excellent PROPRIETARY accuracy as the internal gain setting resistors are precision trimmed OFFSET to within 0.01% matching. The resulting output voltage is equal to CIRCUITRY Q1 V = (I × R ) × 20 OUT SHUNT SHUNT V = (I × R ) × 20 OUT SHUNT SHUNT G = +20 R OUT AD8211 GND Figure 23. Simplified Schematic Rev. A | Page 10 of 16 06824-022 AD8211 APPLICATION NOTES Regardless of the common mode, the AD8211 provides a OUTPUT LINEARITY correct output voltage when the input differential is at least In all current sensing applications, and especially in automotive 2 mV, which is due to the voltage range of the output amplifier and industrial environments where the common-mode voltage that can go as low as 33 mV typical. The specified minimum can vary significantly, it is important that the current sensor output amplifier voltage is 100 mV to provide sufficient guard- maintain the specified output linearity, regardless of the input bands. The ability of the AD8211 to work with very small differential or common-mode voltage. The AD8211 contains differential inputs, regardless of the common-mode voltage, specific circuitry on the input stage, which ensures that even allows for more dynamic range, accuracy, and flexibility in any when the differential input voltage is very small, and the current sensing application. common-mode voltage is also low (below the 5 V supply), the input-to-output linearity is maintained. Figure 24 shows the input differential voltage vs. the corresponding output voltage at different common modes. 200 180 160 140 120 100 80 60 40 IDEAL V (mV) OUT V (mV) @ V = 0V OUT CM 20 V (mV) @ V = 65V OUT CM 0 0 1 2 3 4 5 6 7 8 9 10 DIFFERENTIAL INPUT VOLTAGE (mV) Figure 24. Gain Linearity Due to Differential and Common-Mode Voltage Rev. A | Page 11 of 16 OUTPUT VOLTAGE (mV) 06824-115 AD8211 APPLICATIONS INFORMATION OVERCURRENT DETECTION (<100ns) HIGH-SIDE CURRENT SENSE WITH A LOW-SIDE SWITCH 5 6 7 8 OUT GND NC –IN In such load control configurations, the PWM-controlled AD8214 switch is ground referenced. An inductive load (solenoid) is tied NC V +IN V REG S to a power supply. A resistive shunt is placed between the switch 4 3 2 1 and the load (see Figure 25). An advantage of placing the shunt on the high side is that the entire current, including the recirculation current, can be measured because the shunt remains in the loop when the switch is off. In addition, diagnostics can be enhanced 1 3 2 2 3 1 OUT GND V IN+ because shorts to ground can be detected with the shunt on the high side. In this circuit configuration, when the switch is SHUNT AD8211 closed, the common-mode voltage moves down to near the CLAMP V V+ IN– DIODE negative rail. When the switch is opened, the voltage reversal 5 4 5 4 INDUCTIVE BATTERY LOAD across the inductive load causes the common-mode voltage to 5V be held one diode drop above the battery by the clamp diode. SWITCH INDUCTIVE 1 3 2 2 1 3 LOAD CLAMP OUT GND V IN+ DIODE SHUNT AD8211 BATTERY Figure 26. Battery-Referenced Shunt Resistor V+ V IN– LOW-SIDE CURRENT SENSING 5 4 5 4 SWITCH In systems where low-side current sensing is preferred, the 5V AD8211 provides an integrated solution with great accuracy. Ground noise is rejected, CMRR is typically higher than 90 dB, Figure 25. Low-Side Switch and output linearity is not compromised, regardless of the input differential voltage. HIGH-SIDE CURRENT SENSING In this configuration, the shunt resistor is referenced to the INDUCTIVE 1 3 2 2 3 1 LOAD battery. High voltage is present at the inputs of the current sense CLAMP OUT GND V IN+ DIODE amplifier. In this mode, the recirculation current is again measured AD8211 SWITCH and shorts to ground can be detected. When the shunt is battery BATTERY V+ V referenced, the AD8211 produces a linear ground-referenced IN– 5 4 5 4 analog output. An AD8214 can also be used to provide an over- current detection signal in as little as 100 ns. This feature is 5V SHUNT useful in high current systems where fast shutdown in over- current conditions is essential. Figure 27. Ground-Referenced Shunt Resistor Rev. A | Page 12 of 16 06824-024 06824-026 06824-025 AD8211 OUTLINE DIMENSIONS 3.00 2.90 2.80 5 4 3.00 1.70 2.80 1.60 2.60 1.50 1 2 3 0.95 BSC 1.90 BSC 1.30 1.15 0.90 0.20 MAX 1.45 MAX 0.08 MIN 0.95 MIN 0.55 0.15 MAX 10° 0.45 SEATING 0.60 0.05 MIN 5° 0.50 MAX 0.35 PLANE BSC 0° 0.35 MIN COMPLIANT TO JEDEC STANDARDS MO-178-AA Figure 28. 5-Lead Small Outline Transistor Package [SOT-23] (RJ-5) Dimensions shown in millimeters ORDERING GUIDE 1, 2 Model Temperature Range Package Description Package Option Branding AD8211YRJZ-R2 −40°C to +125°C 5-Lead SOT-23 RJ-5 Y02 AD8211YRJZ-RL −40°C to +125°C 5-Lead SOT-23 RJ-5 Y02 AD8211YRJZ-RL7 −40°C to +125°C 5-Lead SOT-23 RJ-5 Y02 AD8211WYRJZ-R7 −40°C to +125°C 5-Lead SOT-23 RJ-5 Y3N AD8211WYRJZ-RL −40°C to +125°C 5-Lead SOT-23 RJ-5 Y3N 1 Z = RoHS Compliant Part. 2 W = Qualified for Automotive Applications. AUTOMOTIVE PRODUCTS The AD8211WYRJZ models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models. Rev. A | Page 13 of 16 11-01-2010-A AD8211 NOTES Rev. A | Page 14 of 16 AD8211 NOTES Rev. A | Page 15 of 16 AD8211 NOTES ©2007-2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06824-0-3/11(A) Rev. A | Page 16 of 16