AD8202YRM

High Common-Mode Voltage, Single-Supply Difference Amplifier AD8202 Data Sheet FEATURES FUNCTIONAL BLOCK DIAGRAMS NC A1 A2 +VS 7 3 4 6 AD8202 100kΩ G = ×10 G = ×2 +IN A1 –IN +IN 8 –IN 1 +IN A2 –IN 5 10kΩ 200kΩ 200kΩ 10kΩ 2 APPLICATIONS NC = NO CONNECT GND Figure 1. SOIC (R) Package Die Form Transmission control Diesel injection control Engine management Adaptive suspension control Vehicle dynamics control INDUCTIVE LOAD CLAMP DIODE 4-TERM SHUNT The AD8202 is a single-supply difference amplifier for amplifying and low-pass filtering small differential voltages in the presence of a large common-mode voltage (CMV). The input CMV range extends from −6 V to +28 V at a typical supply voltage of 5 V. +VS OUT AD8202 –IN GND A1 A2 NC = NO CONNECT COMMON 04981-002 POWER DEVICE The AD8202 is available in die and packaged form. The MSOP and SOIC packages are specified over a wide temperature range, from −40°C to +125°C, making the AD8202 well-suited for use in many automotive platforms. Figure 2. High Line Current Sensor POWER DEVICE 5V OUTPUT +IN BATTERY NC +VS OUT 14V 4-TERM SHUNT AD8202 –IN CLAMP DIODE COMMON GND A1 A2 INDUCTIVE LOAD NC = NO CONNECT 04981-003 The AD8202 features an externally accessible 100 kΩ resistor at the output of the Preamp A1 that can be used for low-pass filter applications and for establishing gains other than 20. NC 14V GENERAL DESCRIPTION Automotive platforms demand precision components for better system control. The AD8202 provides excellent ac and dc performance keeping errors to a minimum in the user’s system. Typical offset and gain drift in the SOIC package are 0.3 µV/°C and 1 ppm/°C, respectively. Typical offset and gain drift in the MSOP package are 2 µV/°C and 1 ppm/°C, respectively. The device also delivers a minimum CMRR of 80 dB from dc to 10 kHz. 5V OUTPUT +IN BATTERY Rev. H OUT 04981-001 High common-mode voltage range −6 V to +28 V at a 5 V supply voltage Operating temperature range: −40°C to +125°C Supply voltage range: 3.5 V to 12 V Low-pass filter (1-pole or 2-pole) Excellent ac and dc performance ±1 mV voltage offset ±1 ppm/°C typical gain drift 80 dB CMRR min dc to 10 kHz Qualified for automotive applications Figure 3. Low Line Current Sensor 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 ©2004–2013 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com AD8202 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 12 Applications ....................................................................................... 1 Applications..................................................................................... 14 General Description ......................................................................... 1 Current Sensing .......................................................................... 14 Functional Block Diagrams ............................................................. 1 Gain Adjustment ........................................................................ 14 Revision History ............................................................................... 2 Gain Trim .................................................................................... 15 Specifications..................................................................................... 3 Low-Pass Filtering ...................................................................... 15 Single Supply ................................................................................. 3 High Line Current Sensing with LPF and Gain Adjustment 16 Absolute Maximum Ratings ............................................................ 4 Driving Charge Redistribution ADCs ..................................... 16 ESD Caution .................................................................................. 4 Outline Dimensions ....................................................................... 17 Pin Configuration and Function Descriptions ............................. 5 Ordering Guide .......................................................................... 17 Typical Performance Characteristics ............................................. 6 Automotive Products ................................................................. 17 REVISION HISTORY 5/13—Rev. G to Rev. H 2/05—Rev. B to Rev. C Added Unit of mV to Initial Input Offset (RTI), TOPR Parameter; Table 1 ................................................................................................ 3 Changes to Table 1.............................................................................3 Changes to Figure 14.........................................................................8 Changes to Figure 22.........................................................................9 2/13—Rev. F to Rev. G Changes to Features Section and General Description Section....... 1 Changes to Table 1 ............................................................................ 3 Changes to Ordering Guide .......................................................... 17 4/12—Rev. E to Rev. F Changes to Table 3 and Figure 5 ..................................................... 5 10/11—Rev. D to Rev. E Change to Features Section ............................................................. 1 Changes to Ordering Guide .......................................................... 17 Updated Outline Dimensions ....................................................... 17 Added Automotive Products Section........................................... 17 11/05—Rev. C to Rev. D Updated Format .................................................................. Universal Changes to Typical Performance Characteristics ........................ 6 Added Figure 18................................................................................ 8 Added Figure 25 to Figure 27.......................................................... 9 Added Figure 32.............................................................................. 10 Added Figure 37 to Figure 39........................................................ 11 Changes to Theory of Operation .................................................. 12 Added Figure 41.............................................................................. 13 1/05—Rev. A to Rev. B Changes to the General Description ...............................................1 Changes to Specifications .................................................................3 Added Figure 14 to Figure 33 ..........................................................8 Changes to Figure 38...................................................................... 14 Changes to Figure 40 and Figure 41 ............................................ 15 Changes to Ordering Guide .......................................................... 16 11/04—Rev. 0 to Rev. A Changes to the Features ....................................................................1 Changes to the General Description ...............................................1 Changes to Specifications (Table 1) ................................................3 Changes to Absolute Maximum Ratings (Table 2) .......................4 Changes to Pin Function Descriptions (Table 3) ..........................5 Changes to Figure 5 ...........................................................................5 Changes to Figure 9 and Figure 10..................................................6 Updated Outline Dimensions ....................................................... 12 Changes to the Ordering Guide ................................................... 12 7/04—Revision 0: Initial Version Rev. H | Page 2 of 20 Data Sheet AD8202 SPECIFICATIONS SINGLE SUPPLY TOPR = operating temperature range, VS = 5 V, unless otherwise noted, RTI = referred to input, VCM = common-mode voltage. Table 1. Parameter SYSTEM GAIN Initial Error vs. Temperature Gain Drift VOLTAGE OFFSET Initial Input Offset (RTI), TOPR Offset vs. Temperature INPUT Input Impedance Differential Common Mode CMV CMRR2 PREAMPLIFIER Gain Gain Error Output Voltage Range Output Resistance OUTPUT BUFFER Gain Gain Error Output Voltage Range4 Input Bias Current Output Resistance DYNAMIC RESPONSE System Bandwidth Slew Rate NOISE 0.1 Hz to 10 Hz Spectral Density, 1 kHz (RTI) POWER SUPPLY Operating Range Quiescent Current vs. Temperature PSRR TEMPERATURE RANGE For Specified Performance Conditions AD8202 SOIC Min Typ Max AD8202 MSOP Min Typ Max 20 AD8202 Die1 Min Typ Max 0.04 ≤ VOUT ≤ 4.8 V dc, TOPR TOPR ±0.3 ±20 ±0.3 ±20 ±0.3 ±30 V/V % ppm/°C VCM = 0 V, TOPR ±2 ±10 ±2 ±15 ±3 ±15 mV μV/°C 390 205 +28 kΩ kΩ V Continuous VCM = −6 V to +28 V f = dc to 1 kHz f = 10 kHz3 260 135 −6 325 170 20 390 205 +28 82 80 260 135 −6 100 0.02 97 30 50 0.28 30 3.5 0.25 VS = 3.5 V to 12 V 75 TOPR −40 0.02 97 50 0.28 83 3.5 0.25 75 +125 1 −40 100 ±0.3 4.8 103 2 ±0.3 4.8 30 12 1.0 83 +125 40 2 50 0.28 kHz V/μs 10 275 μV p-p nV/√Hz 3.5 0.25 75 −40 V/V % V kΩ V/V % V nA Ω ±0.3 4.8 0.04 10 275 12 1.0 dB dB 10 ±0.3 4.8 103 40 2 10 275 VO = 0.1 V dc 100 0.04 40 2 325 170 82 80 2 ±0.3 4.8 0.04 260 135 −6 10 ±0.3 4.8 103 2 0.04 ≤ VOUT ≤ 4.8 V dc, TOPR VIN = 0.1 V p-p; VOUT = 2.0 V p-p VIN = 0.2 V dc; VOUT = 4 V step 390 205 +28 82 80 10 0.02 97 325 170 20 Unit 12 1.0 83 V mA dB +150 °C Die is specified for operation from −40°C to +150°C ( TOPR for DIE). Source imbalance 20 04981-017 10Ω 1% 04981-016 REXT Data Sheet AD8202 GAIN TRIM Figure 45 shows a method for incremental gain trimming by using a trim potentiometer and external resistor, REXT. The following approximation is useful for small gain ranges: ΔG ≈ (10 MΩ/REXT)% Thus, the adjustment range is ±2% for REXT = 5 MΩ; ±10% for REXT = 1 MΩ, and so on. Low-pass filters can be implemented in several ways by using the AD8202. In the simplest case, a single-pole filter (20 dB/decade) is formed when the output of A1 is connected to the input of A2 via the internal 100 kΩ resistor by tying Pin 3 and Pin 4 and adding a capacitor from this node to ground, as shown in Figure 46. If a resistor is added across the capacitor to lower the gain, the corner frequency increases; it should be calculated using the parallel sum of the resistor and 100 kΩ. 5V OUTPUT 5V OUT NC +VS OUT VDIFF 2 +VS OUT VDIFF 2 fC = AD8202 AD8202 VCM VDIFF 2 VDIFF 2 A1 GND A1 A2 A2 REXT NC = NO CONNECT GAIN TRIM 20kΩ MIN C 04981-019 GND 1 2πC105 C IN FARADS –IN –IN 04981-018 VCM NC NC = NO CONNECT Figure 46. Single-Pole, Low-Pass Filter Using the Internal 100 kΩ Resistor Figure 45. Incremental Gain Trim Internal Signal Overload Considerations When configuring gain for values other than 20, the maximum input voltage with respect to the supply voltage and ground must be considered because either the preamplifier or the output buffer reaches its full-scale output (approximately VS − 0.2 V) with large differential input voltages. The input of the AD8202 is limited to (VS − 0.2)/10 for overall gains ≤ 10 because the preamplifier, with its fixed gain of ×10, reaches its fullscale output before the output buffer. For gains greater than 10, the swing at the buffer output reaches its full scale first and limits the AD8202 input to (VS − 0.2)/G, where G is the overall gain. If the gain is raised using a resistor, as shown in Figure 44, the corner frequency is lowered by the same factor as the gain is raised. Thus, using a resistor of 200 kΩ (for which the gain would be doubled), the corner frequency is now 0.796 Hz/µF (0.039 µF for a 20 Hz corner frequency). 5V OUT +IN NC +VS OUT VDIFF 2 AD8202 VCM C VDIFF 2 –IN GND A2 A1 LOW-PASS FILTERING 255kΩ In many transducer applications, it is necessary to filter the signal to remove spurious high frequency components including noise, or to extract the mean value of a fluctuating signal with a peak-to-average ratio (PAR) greater than unity. For example, a full-wave rectified sinusoid has a PAR of 1.57, a raised cosine has a PAR of 2, and a half-wave sinusoid has a PAR of 3.14. Signals having large spikes can have PARs of 10 or more. When implementing a filter, the PAR should be considered so that the output of the AD8202 preamplifier (A1) does not clip before A2 because this nonlinearity would be averaged and appear as an error at the output. To avoid this error, both amplifiers should clip at the same time. This condition is achieved when the PAR is no greater than the gain of the second amplifier (2 for the default configuration). For example, if a PAR of 5 is expected, the gain of A2 should be increased to 5. C fC(Hz) = 1/C(µF) NC = NO CONNECT 04981-020 +IN +IN Figure 47. 2-Pole, Low-Pass Filter A 2-pole filter (with a roll-off of 40 dB/decade) can be implemented using the connections shown in Figure 47. This is a Sallen-Key form based on a ×2 amplifier. It is useful to remember that a 2-pole filter with a corner frequency f2 and a 1-pole filter with a corner at f1 have the same attenuation at the frequency (f22/f1). The attenuation at that frequency is 40 log (f2/f1), which is illustrated in Figure 48. Using the standard resistor value shown and equal capacitors (see Figure 47), the corner frequency is conveniently scaled at 1 Hz/µF (0.05 µF for a 20 Hz corner). A maximally flat response occurs when the resistor is lowered to 196 kΩ and the scaling is then 1.145 Hz/µF. The output offset is raised by approximately 5 mV (equivalent to 250 µV at the input pins). Rev. H | Page 15 of 20 AD8202 Data Sheet by a 1-pole low-pass filter, set with a corner frequency of 3.6 Hz, providing about 30 dB of attenuation at 100 Hz. A higher rate of attenuation can be obtained using a 2-pole filter with fC = 20 Hz, as shown in Figure 50. Although this circuit uses two separate capacitors, the total capacitance is less than half that needed for the 1-pole filter. FREQUENCY 20dB/DECADE INDUCTIVE LOAD 40LOG (f2/f1) CLAMP DIODE OUTPUT NC +IN f1 BATTERY 04981-021 4-TERM SHUNT NC BATTERY C NC = NO CONNECT OUT 4V/AMP +VS OUT 20kΩ A1 A2 POWER DEVICE VOS/IB NULL COMMON 5% CALIBRATION RANGE fC(Hz) = 0.796Hz/C(µF) (0.22µF FOR fC = 3.6Hz) Figure 49. High Line Current Sensor Interface; Gain = ×40, Single-Pole, Low-Pass Filter A power device that is either on or off controls the current in the load. The average current is proportional to the duty cycle of the input pulse and is sensed by a small value resistor. The average differential voltage across the shunt is typically 100 mV, although its peak value is higher by an amount that depends on the inductance of the load and the control frequency. The common-mode voltage, conversely, extends from roughly 1 V above ground for the on condition to about 1.5 V above the battery voltage in the off condition. The conduction of the clamping diode regulates the common-mode potential applied to the device. For example, a battery spike of 20 V can result in an applied common-mode potential of 21.5 V to the input of the devices. 04981-022 C NC = NO CONNECT COMMON fC(Hz) = 1/C(µF) (0.05µF FOR fC = 20Hz) Figure 50. 2-Pole Low-Pass Filter 191kΩ GND A2 127kΩ AD8202 –IN A1 DRIVING CHARGE REDISTRIBUTION ADCS 5V 14V 4-TERM SHUNT GND POWER DEVICE Figure 49 is another refinement of Figure 2, including gain adjustment and low-pass filtering. +IN C 50kΩ HIGH LINE CURRENT SENSING WITH LPF AND GAIN ADJUSTMENT CLAMP DIODE AD8202 –IN Figure 48. Comparative Responses of 1-Pole and 2-Pole Low-Pass Filters INDUCTIVE LOAD 432kΩ 14V f22/f1 f2 +VS OUT 04981-023 A 1-POLE FILTER, CORNER f1, AND A 2-POLE FILTER, CORNER f2, HAVE THE SAME ATTENUATION –40LOG (f2/f1) AT FREQUENCY f22/f1 5V When driving CMOS ADCs, such as those embedded in popular microcontrollers, the charge injection (∆Q) can cause a significant deflection in the output voltage of the AD8202. Though generally of short duration, this deflection can persist until after the sample period of the ADC expires due to the relatively high open-loop output impedance (typically 21 kΩ) of the AD8202. Including an R-C network in the output can significantly reduce the effect. The capacitor helps to absorb the transient charge, effectively lowering the high frequency output impedance of the AD8202. For these applications, the output signal should be taken from the midpoint of the RLAG − CLAG combination, as shown in Figure 51. Because the perturbations from the analog-to-digital converter are small, the output impedance of the AD8202 appears to be low. The transient response, therefore, has a time constant governed by the product of the two LAG components, CLAG × RLAG. For the values shown in Figure 51, this time constant is programmed at approximately 10 µs. Therefore, if samples are taken at several tenths of microseconds or more, there is negligible charge stack-up. To produce a full-scale output of 4 V, a gain ×40 is used, adjustable by ±5% to absorb the tolerance in the shunt. Sufficient headroom allows 10% overrange (to 4.4 V). The roughly triangular voltage across the sense resistor is averaged Rev. H | Page 16 of 20 5V 4 6 +IN AD8202 RLAG 1kΩ A2 5 –IN 10kΩ CLAG 0.01µF MICROPROCESSOR A/D 10kΩ 2 Figure 51. Recommended Circuit for Driving CMOS A/D 04981-024 ATTENUATION 40dB/DECADE Data Sheet AD8202 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) 6.20 (0.2441) 5.80 (0.2284) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) COPLANARITY 0.10 SEATING PLANE 8 0.50 (0.0196) 0.25 (0.0099) 3.20 3.00 2.80 1 45° 5 5.15 4.90 4.65 4 PIN 1 IDENTIFIER 8° 0° 0.65 BSC 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-012-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 0.95 0.85 0.75 15° MAX 1.10 MAX 0.15 0.05 COPLANARITY 0.10 0.40 0.25 6° 0° 0.80 0.55 0.40 0.23 0.09 10-07-2009-B 5 1 012407-A 8 4.00 (0.1574) 3.80 (0.1497) 3.20 3.00 2.80 COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 53. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters Figure 52. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model 1, 2 AD8202WYC-P3 AD8202WYC-P7 AD8202WYRMZ AD8202WYRMZ-RL AD8202WYRZ AD8202WYRZ-RL AD8202YRMZ AD8202YRMZ-R7 AD8202YRMZ-RL AD8202YRZ AD8202YRZ-RL AD8202YRZ-R7 1 2 Temperature Range −40°C to +150°C −40°C to +150°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C Package Description Die Die 8-Lead Mini Small Outline Package [MSOP] 8-Lead Mini Small Outline Package [MSOP] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Mini Small Outline Package [MSOP] 8-Lead Mini Small Outline Package [MSOP] 8-Lead Mini Small Outline Package [MSOP] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Standard Small Outline Package [SOIC_N] Package Option Branding RM-8 RM-8 R-8 R-8 RM-8 RM-8 RM-8 R-8 R-8 R-8 JWY JWY JWY JWY JWY Z = RoHS Compliant Part. W = Qualified for Automotive Applications. AUTOMOTIVE PRODUCTS The AD8202W 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. H | Page 17 of 20 AD8202 Data Sheet NOTES Rev. H | Page 18 of 20 Data Sheet AD8202 NOTES Rev. H | Page 19 of 20 AD8202 Data Sheet NOTES © 2004–2013 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04981-0-5/13(H) Rev. H | Page 20 of 20