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bidirectional, zero drift, current sense amplifier data sheet AD8417 features typical 0.1 v/c offset drift maximum 400 v voltage offset over full temperature range 2.7 v to 5.5 v power supply operating range electromagnetic interference (emi) filters included high common - mode input voltage range ? 2 v to +70 v continuou s ? 4 v to +85 v survival initial gain = 60 v/v wide operating temperature range: ? 40c to +125c bidirectional operation available in 8 - lead soic and 8 - lead msop common - mode rejection ratio (cmrr): 86 db, dc to 10 khz qualified for automotive applicatio ns applications high - side current sensing in motor controls solenoid controls power management low - side current sensing diagnostic protection general description the AD8417 is a high voltage, h igh resolution current shunt amplifier. it features an initial gain of 60 v/v, with a maximum 0.3% gain error over the entire temperature range. the buffered output voltage directly interfaces with any typical converter. the AD8417 offers excellent input common - mode rejection from ?2 v to +70 v. the AD8417 performs bidirectional current measurements across a shunt resistor in a variety of a utomot ive and industrial applications, including motor control , power management, and solenoid control. the AD8417 offers breakthrough performance throughout the ? 40c to +125c temperature range. it features a zero drift core, which leads to a typical offset drift of 0.1 v/c throughout the operating temperature range and the common - mode voltage range. the AD8417 is qualified for automoti ve applications . the device includes emi filters and patented circuitry to enable output accuracy with pulse - width modulation (pwm) type input common - mode voltages. the typical input offset voltage is 200 v. t h e AD8417 is offered in 8 - lead msop and soic packages. table 1 . related devices part no. description ad8205 current sense amplifier, gain = 50 ad8206 current sense amplifier, gain = 20 ad8207 high accuracy current sense amplifier, gain = 20 ad8210 high speed current sense amplifier, gain = 20 ad8418 a high accuracy current sense amplifier, gain = 20 functional block dia gram + i shunt g = 60 v cm = ?2v to +70v v s = 2.7v to 5.5v v ref 1 v ref 2 out 0v v s v s /2 v out i shunt emi filter emi filter v cm 0v 70v AD8417 v s +in ?in ? gnd ?50a 50a r shunt 1 1882-001 figure 1. rev. 0 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 ? 2013 analog devices, inc. all rights reserved. technical support www.analog.com
AD8417 data sh eet table of co ntents features .............................................................................................. 1 applications ....................................................................................... 1 general description ......................................................................... 1 functional block diagram .............................................................. 1 revision history ............................................................................... 2 specifications ..................................................................................... 3 absolute maximum ratings ............................................................ 4 esd caution .................................................................................. 4 pin configuration and function descriptions ............................. 5 typical p erformance characteristics ............................................. 6 theory of operation ...................................................................... 10 output offset adjustment ............................................................. 11 unidirectional operation .......................................................... 11 bidirectional operation ............................................................. 11 external referenced output ..................................................... 12 splitting the supply .................................................................... 12 splitting an external reference ................................................ 12 applications information .............................................................. 13 m otor control ............................................................................. 13 solenoid control ........................................................................ 14 outline dimensions ....................................................................... 15 ordering guide .......................................................................... 16 automotive products ................................................................. 16 revision history 11 /13 revision 0: initial version rev. 0 | page 2 of 16
data sheet AD8417 specifications t a = ? 40c to +125c (operating temperature range), v s = 5 v, unless otherwise noted. table 2. parameter test conditions/comments min typ max unit gain initial 60 v/v error over temperature specified temperature range 0.3 % gain vs. temperature ? 10 +10 ppm/c voltage offset offset voltage, referred to the input (rti) 25c 200 v over temperature (rti) specified temperature range 400 v offset drift ? 0.4 +0.1 +0.4 v/c input input bias current 130 a input voltage range common mode, continuous ?2 +70 v common - mode rejection ratio (cmrr) specified temperature range, f = dc 90 100 db f = dc to 10 khz 86 db output output voltage range r l = 25 k? 0.045 v s ? 0.035 v output resistanc e 2 ? dynamic response small signal ?3 db bandwidth 250 khz slew rate 1 v/s noise 0.1 hz to 10 hz (rti) 2.3 v p - p spectral density, 1 khz (rti) 110 nv/ hz offset adjustment ratiometric accuracy 1 divider to supplies 0 .499 0.501 v/v accuracy, referred to the output (rto) voltage applied to v ref 1 and v ref 2 in parallel 1 mv/v output offset adjustment range v s = 5 v 0.045 v s ? 0.035 v power supply operating range 2.7 5.5 v quiescent current over temper a tur e v out = 0.1 v dc 4.1 ma power supply rejection ratio 80 db temperature range for specified performance operating temperature range ? 40 +125 c 1 the offset adjustment is ratiometric to the power supply when v ref 1 and v ref 2 are used as a divider between the supplies. rev. 0 | page 3 of 16
AD8417 data sheet absolute maximum rat ings table 3 . parameter rating supply voltage 6 v input voltage range continuous ? 2 v to +70 v survival ? 4 v to +85 v differential input survival 5.5 v reverse supply voltage 0.3 v esd human body model (hbm) 2000 v operating temperature range ? 40c to +125c storage temperature range ? 65 c to +150c 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; 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. 0 | page 4 of 16
data sheet AD8417 pin configuration and function descripti ons nc = no connect. do not connect to this pin. ?in 1 gnd 2 v ref 2 3 nc 4 +in 8 v ref 1 7 v s 6 out 5 AD8417 top view (not to scale) 1 1882-002 figure 2 . pin configuration table 4 . pin function descriptions pin no. mnemonic description 1 ? in negative input. 2 gnd ground. 3 v ref 2 reference input 2. 4 nc no connect. do not connect to this pin. 5 out output. 6 v s supply. 7 v ref 1 reference input 1. 8 +in positive input. rev. 0 | page 5 of 16
AD8417 data sheet typical performance characteristics 0 2 4 6 8 10 12 14 ?40 ?25 ?10 5 20 35 50 65 80 95 1 10 125 offset vo lt age (v) tempera ture ( c) 1 1882-003 figure 3 . typical offset voltage drift vs. temperature 50 60 70 80 90 100 1 10 120 10 100 1k 10k 100k 1m cmrr (db) frequenc y (hz) 1 1882-004 figure 4 . typical cmrr vs. frequency ?500 ?400 ?300 ?200 ?100 0 100 200 300 400 500 ?40 ?25 ?10 5 20 35 50 65 80 95 1 10 125 gain error (v/v) tempera ture ( c) normalized a t 2 5 c 1 1882-005 figure 5 . typical gain error vs. temperature ?40 ?30 ?20 ?10 0 10 20 30 40 50 1000 10k 100k 1m 10m gain (db) frequenc y (hz) 1 1882-006 figure 6 . typical small si gnal bandwidth (v out = 200 mv p - p) 0 1 2 3 4 5 6 7 8 9 10 40 35 3025 20 differentia l input vo lt age (mv) 15 5 10 0 total output error (%) 1 1882-007 figure 7 . total output error vs. differential input voltage ?0.5 ?0.4 ?0.3 ?0.2 ?0.1 0 0.1 0.2 0.3 0.4 0.5 ?4 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 bias current per input pin (ma) v cm (v) v s = 2.7v ?in +in 1 1882-008 figure 8 . bias current per input pin vs. common - mode voltage (v cm ) rev. 0 | page 6 of 16
data sheet AD8417 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 ?5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 supply current (ma) input common-mode vo lt age (v) v s = 5v v s = 2.7v 1 1882-009 figure 9 . supply current vs. input common - mode voltage time (1s/div) output input 25mv/div 500mv/div v s = 2.7v 1 1882-010 figure 10 . rise time (v s = 2.7 v) time (1s/div) 25mv/div 500mv/div input output 1 1882-0 11 v s = 5v figure 11 . rise time (v s = 5 v) time (1s/div) 25mv/div 1v/div v s = 2.7v input output 1 1882-012 figure 12 . fall time (v s = 2.7 v) time (1s/div) 25mv/div 1v/div v s = 5v input output 1 1882-013 figure 13 . fall time (v s = 5 v) time (1s/div) 25mv/div 1v/div v s = 2.7v input output 1 1882-014 figure 14 . differential overload recovery, rising (v s = 2.7 v) rev. 0 | page 7 of 16
AD8417 data sheet time (1s/div) 50mv/div 2v/div v s = 5v input output 1 1882-015 figure 15 . differential overload recovery, rising (v s = 5 v) time (1s/div) 25mv/div 1v/div v s = 2.7v input output 1 1882-016 figure 16 . differential overload recovery, falling (v s = 2.7 v) time (1s/div) 50mv/div 2v/div v s = 5v input output 1 1882-017 figure 17 . differential overload recovery, falling (v s = 5 v) time (4 s/div) input common mode 40v/div output 100mv/div 1 1882-018 figure 18 . input common - mode step response (v s = 5 v, inputs shor ted) 0 5 10 15 20 25 30 35 40 45 ?40 ?25 ?10 5 20 35 50 65 80 95 1 10 125 maximum output sink current (ma) 2.7v 5v 1 1882-019 figure 19 . maximum output sink current vs. temperature 0 5 10 15 20 25 30 35 40 ?40 ?25 ?10 5 20 35 50 65 80 95 1 10 125 maximum output source current (ma) 2.7v 5v 1 1882-020 figure 20 . maximum output source current vs. temperature rev. 0 | page 8 of 16
data sheet AD8417 ?500 ?450 ?400 ?350 ?300 ?250 ?200 ?150 ?100 ?50 0 0 1 2 3 4 5 6 7 8 9 10 output vo lt age range from positive rai l (mv) output source current (ma) 1 1882-021 figure 21 . output voltage range from positive ra il vs. output source current 0 50 100 150 200 250 300 0 1 2 3 4 5 6 7 8 9 10 output vo lt age range from positive rai l (mv) output sink current (ma) 1 1882-022 figure 22 . output voltage range from ground vs. output sink current ?400 ?300 ?200 ?100 0 100 200 300 400 0 300 600 900 1200 1500 1800 v osi with v cc = 5.0v (v) ?40c +25c +125c hits 1 1882-023 figure 23 . offset voltage distribution ?0.15 ?0.10 ?0.05 0 0.05 0.10 0.15 ?40 ?25 ?10 5 20 35 50 65 80 95 1 10 125 cmrr (v/v) normalized a t 25c 1 1882-024 figure 24 . cmrr vs. temperatu re ?8 ?6 ?4 ?2 0 2 4 6 8 0 300 600 900 1200 1500 1800 2100 2400 gain error drift (ppm/c) hits 1 1882-125 figure 25 . gain error drift distribution rev. 0 | page 9 of 16
AD8417 data sheet theory of operation the AD8417 is a single - supply, zero drift, difference amplifier that uses a unique architecture t o accurately amplify small differential current shunt voltages in the presence of rapidly changing co m mon - mode voltages. in typical applications, the AD8417 measure s current by amplifying the volta ge across a shunt resistor connected to its inputs by a gain of 60 v/v (see figure 26 ). the AD8417 design provide s excellent common - mode rejection , even with pwm common -m ode inputs that can change at very fast rates, for example, 1 v/ns. the AD8417 contains patented technology to eliminate the negative effects of such fast changing external common - mode variations. the AD8417 features an input offset drift of less than 0.4 v/c. this performance is achieved through a novel zero drift architecture that does not compromise bandwidth, which is typically rated at 250 khz. the reference inputs, v ref 1 and v ref 2, are tied through 100 k? resistors to the positive input of the main amplifier, which allows the output of fset to be adjusted anywhere in the output operating range. the gain is 1 v/v from the reference pi ns to the output when the reference pins are used in parallel. when the pins are used to divide the supply, the gain is 0.5 v/v. the AD8417 offers breakthrough performance without compromising any of the robust application needs typical of solenoid or motor control. the ability to reject pwm input common - mode voltages and the zero drift architecture providing low offset and offset drift allows the AD8417 to deliver total accuracy for these demanding applications. + i shunt g = 60 v cm = ?2v to +70v v s = 2.7v to 5.5v v ref 1 v ref 2 out 0v v s v s /2 v out i shunt emi filter emi filter v cm 0v 70v AD8417 v s +in ?in ? gnd ?50a 50a r shunt 1 1882-225 figure 26 . typical application rev. 0 | page 10 of 16
data sheet AD8417 output offset adjust ment the output of the AD8417 can be a djusted for unidirectional or bidirectional operation. unidirectional opera tion unidirectional operation allows the AD8417 to measure cu r rents through a resistive shunt in one direction. the basic modes for unidirectional operation are ground referenced ou t put mode and v s referenced output mode. for unidirectional operation, the output can be set at the negative rail (near ground) or at the positive rail (near v s ) when the differential input is 0 v . the output moves to the opposite rail when a correct polarity differential input voltage is applied. the re quired polarity of the differential input depends on the output voltage setting. if the output is set at the positive rail, the input polarity must be negative to decrease the output . if the output is set at ground, the polarity must be positive to increase the output . ground referenced output mode when using the AD8417 in ground referenced output mode, both referenced inputs are tied to ground, which causes the output to sit at the negative rail when there are zero differential volts at the input (see figure 27 ). ? + r1 out gnd v s v ref 1 v ref 2 AD8417 r2 r3 r4 ?in +in 1 1882-025 figure 27 . ground referenc ed output v s referenced output mode v s referenced output mode is set when both reference pins are tied to the positive supply. it is typically used when the diagnostic scheme r e quires detection of the amplifier and the wiring before power is appl ied to the load (see figure 28). ? + r1 out gnd v s v ref 1 v ref 2 AD8417 r2 r3 r4 ?in +in 1 1882-026 figure 28 . v s referenced output bidirectional operat ion bidirectional operation allows the AD8417 to measure cu rrents through a resistive shunt in two directions. in this case, the output is set anywhere within the output range. typically, it is set at half - scale for equal range in both directions. in some cases, however, it is set at a voltage other than half scal e when the bidirectional current is nonsymmetrical. adjusting the output is accomplished by applying voltage(s) to the referenced inputs. v ref 1 and v ref 2 are tied to internal resistors that connect to an internal offset node. there is no operational differ ence between the pins. rev. 0 | page 11 of 16
AD8417 data sheet external referenced output tying both pins together and to a reference produces an output equal to the reference voltage when there is no differential input ( see figure 29 ). t he output decreases the reference vol t age when the input is negative, relative to the ? in pin, and increases when the input is positive, relative to the ?in pin. ? + r1 out gnd v s v ref 1 v ref 2 AD8417 r2 r3 r4 ?in +in 2.5v 1 1882-027 figure 29 . external referenced output splitting the supply by tying one reference pin to v s and the other to the ground pin , the output is set at half o f the supply when there is no di f ferential input (see figure 30 ). the benefit of this configuration is that an external reference is not required to offset the output for bidirectional current measurement. tying on e reference pin to v s and the other to the ground pin creates a midscale offset that is rat i ometric to the supply, which means that if the supply increases or decreases, the output remains at half the supply. for exa m ple, if the supply is 5.0 v, the output is at half scale or 2.5 v. if the su p ply increases by 10% (to 5.5 v), the output increases to 2.75 v. ? + r1 out gnd v s v ref 1 v ref 2 AD8417 r2 r3 r4 ?in +in 1 1882-028 figure 30 . split supply splitting an externa l reference use t he internal reference resistors to divide an external reference b y 2 with an a c curacy of approximately 0.5%. split an external reference by connecting one v ref x pin to ground and the other v ref x pin to the reference (see figure 31). ? + r1 out gnd v s v ref 1 v ref 2 AD8417 r2 r3 r4 ?in +in 5v 1 1882-029 figure 31 . split external reference rev. 0 | page 12 of 16
data sheet AD8417 applications informa tion motor control 3- phase motor control the AD8417 is ideally suited for monitoring current in 3 - phase motor applications. the 250 khz typical bandwidth o f the AD8417 provides instantaneous current monitoring. additionally, the typical low offset drift of 0.1 v/c means that the measurement error bet ween the two motor phases is at a minimum over te mperature . the AD8417 rejects pwm input common - mode voltages in the ? 2 v to +70 v (with a 5 v supply) range. monitoring the current on the motor phase allows sampling of the current at any point an d provides diagnostic information , such as a short to gnd and battery. refer to figure 33 for the typical phase current measurement setup with the AD8417 . h- bridge motor control another typical application for the AD8417 is to form part of the control loop in h - bridge motor control. in this case, place the shunt resistor in the middle of the h - bridg e to accurately measure current in both directions by using the shunt available at the motor (see figure 32 ). using an amplifier and shunt in this location is a better sol u tion than a ground referenced op amp because ground is not typically a stable reference voltage in this type of applic a tion. the instability of the ground reference causes inaccuracies in the measur e ments that can be made with a simple ground referenced op amp. the AD8417 measures current in both directions as the h - bridge switches and the motor changes direction. the output of the AD8417 is configured in an external referenced bidire c tional mode ( see the bidirectional operation section). AD8417 +in shunt mot or v ref 1 v s out ?in gnd 5v controller v ref 2 nc 5v 2.5v 1 1882-030 figure 32 . h - bridge motor control AD8417 bidirectiona l current measurement rejection of high pwm common-mode vo lt age (?2v t o +70v) amplific a tion high output drive ad8214 inter f ace circuit v+ i u i v i w v? optiona l device for overcurrent protection and f ast (direct) shutdown of power s t age AD8417 controller 5v 5v m 1 1882-031 figure 33 . 3 - phase motor control rev. 0 | page 13 of 16
AD8417 data sheet solenoid control high - side current sense with a low - side switch in the case of a high - side current sense with a low - side switch, the pwm control switch is ground referenced. tie a n inductive load (solenoid) to a power supply and place a resistive shunt between the switch and the load (see figure 34 ). an advantage of placing the shunt on the high side is that the entire current, including the recirculation current, is measurable because the shunt remains in the loop when the switch is off. in addition, diagnostics are enhanced becaus e shorts to ground are detected with the shunt on the high side . in this circuit configuration, when the switch is closed, the common - mode voltage decreases to near the negative rail. when the swit ch is open, the voltage reversal across the i n ductive load causes the common - mode voltage to be held one diode drop above the battery by the clamp diode. ?in 1 gnd 2 v ref 2 3 nc 4 +in 8 v ref 1 7 v s 6 out output 5v inductive load clamp diode battery switch shunt nc = no connect. + ? 5 AD8417 1 1882-032 figure 34 . low - side switch high - side current sense with a high - side switch the high - side current sense with a high - side switch config uration minimizes the possibility of unexpected solenoid activation and excessive corrosion (see figure 35 ). in this case, both the switch and the shunt are on the high side. when the switch is off, the battery is removed from the load, which prevents damage from potential shorts to ground while still allowing the recirculating current to be measured and to pr o vide diagnostics. removing the power supply from the load for the majority of the time that the switch is open minimizes th e corrosive effects that can be caused by the differential voltage between the load and ground. when using a high - side switch, the battery voltage is connected to the l oad when the switch is closed, causing the common - mode voltage to increase to the batter y voltage. in this case, when the switch is open, the voltage reversal across the i n ductive load causes the common - mode voltage to be held one diode drop below ground by the clamp diode. ?in 1 gnd 2 v ref 2 3 nc 4 +in 8 v ref 1 7 v s 6 out output 5v inductive load shunt clamp diode battery switch nc = no connect. + ? 5 AD8417 1 1882-033 figure 35 . high - side switch high rail curr ent sensing 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 AD8417 produces a linear ground referenced analog output. additionally, the ad8214 provide s an overcurrent detection signal in as little as 100 ns (see figure 36 ). this feature is useful in high current systems where fast shutdown in overcurrent conditions is essential. v s 1 +in 2 v reg 3 nc 4 ?in 8 nc 7 gnd 6 out output overcurrent detection (<100ns) 5v shunt inductive load switch clamp diode battery + ? 5 ad8214 nc = no connect. ?in 1 gnd 2 v ref 2 3 nc 4 +in 8 v ref 1 7 v s 6 out 5 AD8417 top view (not to scale) 1 1882-034 figure 36 . high rail current sensing rev. 0 | page 14 of 16
data sheet AD8417 outline dimensions contro lling d imensio ns are i n milli meters ; inc h di mens ions (in par enthese s) are rounde d-off m illimet er equ ival ents for refer ence only an d are not ap prop riat e for u se in desi gn. complia nt to jed ec s tand ard s ms -012 -aa 01 24 07 -a 0.25 (0. 009 8) 0.17 (0. 0067) 1.27 (0 .0500) 0.4 0 (0. 0157 ) 0.50 (0.0 196) 0.25 (0 .0099) 45 8 0 1.75 (0 .06 88) 1.35 (0 .0532 ) seat ing plane 0.2 5 (0 .009 8) 0.10 (0 .0040 ) 4 1 8 5 5. 00 ( 0. 19 68) 4.80 (0 .1890) 4.0 0 (0 .157 4) 3.8 0 (0 .149 7) 1. 27 ( 0.05 00) bsc 6.20 (0. 244 1) 5.8 0 (0 .228 4) 0.5 1 ( 0.0 20 1) 0.31 (0 .0122) copl anar ity 0.10 figure 37 . 8 - lead standard small outline package [soic_n] narrow body (r- 8) dimensions shown in millimeters and (inches) compliant to jedec standards mo-187-aa 6 0 0.80 0.55 0.40 4 8 1 5 0.65 bsc 0.40 0.25 1.10 max 3.20 3.00 2.80 coplanarity 0.10 0.23 0.09 3.20 3.00 2.80 5.15 4.90 4.65 pin 1 identifier 15 max 0.95 0.85 0.75 0.15 0.05 10-07-2009-b figure 38 . 8 - lead mini small outline package [msop] (rm - 8) dimensions shown in millimeters rev. 0 | page 15 of 16
AD8417 data sh eet orderi ng guide model 1 , 2 temperature range package description package option branding AD8417brmz ? 40c to +125c 8- lead msop rm -8 y4y AD8417brmz -rl ? 40c to +125c 8- lead msop, 13 tape and reel rm -8 y4y AD8417wbrmz ? 40c to +125c 8- lead msop rm -8 y4x ad84 17wbrmz -rl ? 40c to +125c 8- lead msop, 13 tape and reel rm -8 y4x AD8417wbrz ? 40c to +125c 8- lead soic_n r-8 AD8417wbrz -rl ? 40c to +125c 8- lead soic_n, 13 tape and reel r-8 1 z = rohs compliant part. 2 w = qualified for automotive applications. automotive products the AD8417 w 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 represent ative for specific product ordering information and to obtain the specific automotive reliability reports for these models. ? 2013 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. d11882 -0- 11/13(0) rev. 0 | page 16 of 16

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