View AD8215_4882967.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

high voltage, current shunt monitor AD8215 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. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.461.3113 ?2008 analog devices, inc. all rights reserved. features 4000 v hbm esd high common-mode voltage range ?2 v to +65 v operating ?3 v to +68 v survival buffered output voltage wide operating temperature range 8-lead soic_n: ?40c to +125c excellent ac and dc performance 6 v/c typical offset drift ?8 ppm/c typical gain drift 120 db typical cmrr at dc applications high-side current sensing motor controls transmission controls engine management suspension controls vehicle dynamic controls dc-to-dc converters functional block diagram 07203-001 in+ v+ out g = +20 AD8215 a1 proprietary offset circuitry in? gnd figure 1. general description the AD8215 is a high voltage, precision current shunt monitor. it features a set gain of 20 v/v, with a maximum 0.3% gain error over the entire temperature range. the buffered output voltage directly interfaces with any typical converter. excellent common- mode rejection from ?2 v to +65 v is independent of the 5 v supply. the AD8215 performs unidirectional current measurements across a shunt resistor in a variety of industrial and automotive applications, such as motor controls, solenoid controls, or battery management. special circuitry is devoted to output linearity being maintained throughout the input differential voltage range of 0 mv to 250 mv, regardless of the common-mode voltage present. the AD8215 has an operating temperature range of ?40c to +125c and is offered in a small 8-lead soic_n package.
AD8215 rev. 0 | page 2 of 16 table of contents features .............................................................................................. 1 applications ....................................................................................... 1 functional block diagram .............................................................. 1 general description ......................................................................... 1 revision history ............................................................................... 2 specifications ..................................................................................... 3 absolute maximum ratings ............................................................ 4 esd caution .................................................................................. 4 pin configuration and function descriptions ............................. 5 typical performance characteristics ............................................. 6 theory of operation ...................................................................... 10 application notes ........................................................................... 11 output linearity ......................................................................... 11 applications information .............................................................. 12 high-side current sensing with a low-side switch ............. 12 high-side current sensing ....................................................... 12 low-side current sensing ........................................................ 12 outline dimensions ....................................................................... 13 ordering guide .......................................................................... 13 revision history 1/08revision 0: initial version
AD8215 rev. 0 | page 3 of 16 specifications t opr = ?40c to +125c, t a = 25c, v s = 5 v, r l = 25 k (r l is the output load resistor), unless otherwise noted. table 1. parameter min typ max unit conditions gain initial 20 v/v accuracy 0.15 % v o 0.1 v dc, t a accuracy over temperature 0.3 % t opr drift 0 ?8 ?15 ppm/c t opr voltage offset offset voltage, rti 1 mv t a over temperature, rti 2.5 mv t opr drift ?15 +6 +18 v/c t opr input input impedance differential 5 k common mode 5 m common-mode voltage > 5 v 3.5 k common-mode voltage < 5 v common-mode input voltage range ?2 +65 v common-mode continuous differential input voltage range 250 mv differential input voltage common-mode rejection ratio 100 120 db t opr , f = dc to 50 khz, v cm > 5 v 80 90 db t opr , f = dc to 40 khz, v cm < 5 v output output voltage range low 0.03 v t a 0.10 v t opr output voltage range high 4.95 v t a 4.90 v t opr output impedance 2 dynamic response small signal ?3 db bandwidth 450 khz t opr slew rate 4.5 v/s t a noise 0.1 hz to 10 hz, rti 7 v p-p spectral density, 1 khz, rti 70 nv/hz power supply operating range 4.5 5.5 v quiescent current over temperature 1.3 2.2 ma v cm > 5 v 1 , t opr power supply rejection ratio 75 db t opr temperature range for specified performance ?40 +125 c 1 when the input common-mode voltage is less than 5 v, the supply current increases, which can be calculated by i s = ?0.275 (v cm ) + 2.5.
AD8215 rev. 0 | page 4 of 16 absolute maximum ratings table 2. parameter rating supply voltage 12.5 v continuous input voltage ?3 v to +68 v continuous differential input voltage 0.5 v reverse supply voltage ?0.3 v human body model (hbm) esd rating 4000 v charged device model (cdm) esd rating 1000 v operating temperature range ?40c to +125c storage temperature range ?65c 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
AD8215 rev. 0 | page 5 of 16 pin configuration and fu nction descriptions 07203-002 5 1 2 5 6 8 figure 2. metallization diagram ?in 1 gnd 2 nc 3 nc 4 +in 8 nc 7 v+ 6 out 5 nc = no connect AD8215 top view (not to scale) 07203-003 figure 3. pin configuration table 3. pin function descriptions pin o. neonic description 1 ?in ?228 +519 inverting input. 2 gnd ?273 ?251 ground. 3, 4, 7 nc n/a n/a no connect. 5 out +265 ?466 buffered output. 6 v+ +273 ?266 supply. 8 +in +229 +519 noninverting input.
AD8215 rev. 0 | page 6 of 16 typical performance characteristics ?1.2 ?1.0 ?0.8 ?0.6 ?0.4 ?0.2 0 0.4 0.2 0.6 0.8 1.0 1.2 ?40 ?20 0 20 40 60 80 100 120 0 7203-017 temperature (c) v osi (mv) figure 4. typical offset drift vs. temperature 07203-024 frequency (hz) cmrr (db) 60 70 80 90 100 110 120 130 140 10 100 1k 10k 100k 1m common-mode voltage >5v common-mode voltage <5v figure 5. typical cmrr vs. frequency ?2500 ?2000 ?1500 ?1000 ?500 0 500 1000 1500 2000 2500 ?40 ?20 0 20 40 60 80 100 120 07203-016 temperature (c) gain error (ppm) figure 6. typical gain error vs. temperature ?40 ?35 ?30 ?25 ?20 ?15 ?10 ?5 0 5 10 15 20 25 30 35 40 10k 100k 1m 10m 07203-018 frequency (hz) gain (db) figure 7. typical small signal bandwidth (v out = 200 mv p-p) 0 1 2 3 4 5 6 7 8 9 10 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 differential input voltage (mv) total output error (%) 250 07203-022 figure 8. total output error vs. differential input voltage ?570 ?560 ?550 ?540 ?530 ?520 ?510 ?500 ?490 ? 480 v in+ v in? 0 25 50 75 100 125 150 175 200 225 250 07203-007 differential input voltage (mv) input bias current (a) figure 9. input bias current vs. differential input voltage, v cm = 0 v
AD8215 rev. 0 | page 7 of 16 40 50 60 70 80 90 100 110 120 0 25 50 75 100 125 150 175 200 225 250 in+ in? 0 7203-006 differential input voltage (mv) input bias current (a) figure 10. input bias current vs . differential input voltage, v cm = 5 v ?2.4 ?2.0 ?1.6 ?1.2 ?0.8 ?0.4 0 0.4 0.8 ?4?20246865 0 7203-004 input common-mode voltage (v) input bias current (ma) figure 11. input bias current vs. input common-mode voltage 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ?4 ?2 0 2 4 6 8 65 07203-005 input common-mode voltage (v) supply current (ma) figure 12. supply current vs. common-mode voltage time (400ns/div) 07203-012 2 1 100mv/div input output 1v/div figure 13. fall time time (400ns/div) 07203-015 2 1 100mv/div input output 1v/div figure 14. rise time time (1s/div) 07203-013 2 1 200mv/div input output 2v/div figure 15. differential overload recovery (falling)
AD8215 rev. 0 | page 8 of 16 time (1s/div) 07203-014 2 1 200mv/div input output 2v/div figure 16. differential overload recovery (rising) time (4s/div) 07203-019 2 1 2v/div 0.01%/div figure 17. settling time (falling) time (4s/div) 07203-020 2 1 2v/div 0.01%/div figure 18. settling time (rising) 5 6 7 8 9 10 11 12 ?40 ?20 0 20 40 60 80 100 120 140 07203-010 temperature (c) maximum output sink current (ma) figure 19. maximum output sink current vs. temperature 4 5 6 7 8 9 10 ?40 ?20 0 20 40 60 80 100 120 140 07203-011 temperature (c) maximum output source current (ma) figure 20. maximum output source current vs. temperature 1.0 1.4 1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 0123456789 0 7203-008 output source current (ma) output voltage range (v) figure 21. output voltage range vs. output source current
AD8215 rev. 0 | page 9 of 16 0 0.4 0.8 1.2 1.6 2.0 0 1 2 3 4 5 6 7 8 9 10 11 12 07203-009 output sink current (ma) output voltage range (v) figure 22. output voltage range fr om gnd vs. output sink current 07203-021 v os (mv) count 0 ?2 0 ?1 1 2 500 1000 1500 2000 2500 3000 3500 +125c +25c ?40c figure 23. offset distribution 07203-023 gain drift (ppm/c) count 0 ?2?4?6 ?8 ?10 ?12 ?14 ?16 0 300 600 900 1200 1500 1800 2100 2400 figure 24. gain drift distribution 07203-030 offset drift (v/c) count 0 15 10 50 ?5 ?10 ?15 ?20 20 200 400 600 800 1000 1200 1400 1600 figure 25. offset drift
AD8215 rev. 0 | page 10 of 16 theory of operation in typical applications, the AD8215 amplifies a small differential input voltage generated by the load current flowing through a shunt resistor. the AD8215 rejects high common-mode voltages (up to 65 v) and provides a ground-referenced, buffered output that interfaces with an analog-to-digital converter (adc). figure 26 shows a simplified schematic of the AD8215. 07203-025 v+ out = (i shunt r shunt ) 20 g = +20 AD8215 a1 r1 r out i in r proprietary offset circuitry gnd i shunt r shunt figure 26. simpli fied schematic a load current flowing through the external shunt resistor produces a voltage at the input terminals of the AD8215. the input terminals are connected to a1 by r and r1. the inverting terminal, which has very high input impedance, is held to ( v cm ) ? (i shunt r shunt ) because negligible current flows through r. a1 forces the noninverting input to the same potential. therefore, the current that flows through r1 is equal to i in = ( i shunt r shunt )/ r1 this current (i in ) is converted back to a voltage via r out . the output buffer amplifier has a gain of 20 v/v and offers excellent accuracy as the internal gain setting resistors are precision trimmed to within 0.01% matching. the resulting output voltage is equal to out = ( i shunt r shunt ) 20
AD8215 rev. 0 | page 11 of 16 application notes output linearity in all current sensing applications, and especially in automotive and industrial environments where the common-mode voltage can vary significantly, it is important that the current sensor maintain the specified output linearity, regardless of the input differential or common-mode voltage. the AD8215 contains specific circuitry on the input stage, which ensures that even when the differential input voltage is very small and the common-mode voltage is also low (below the 5 v supply), the input-to-output linearity is maintained. figure 27 shows the differential input voltage vs. the corresponding output voltage at different common modes. 200 0 0 07203- 026 differential input voltage (mv) output voltage (mv) 10 180 160 140 120 100 80 60 40 20 123456789 ideal v out (mv) v out (mv) @ v cm =0v v out (mv) @ v cm =65v figure 27. gain linearity due to differential and common-mode voltage regardless of the common mode, the AD8215 provides a correct output voltage when the differential input is at least 2 mv, which is due to the voltage range of the output amplifier that can go as low as 33 mv typical. the specified minimum output amplifier voltage is 100 mv to provide sufficient guard- bands. the ability of the AD8215 to work with very small differential inputs, regardless of the common-mode voltage, allows for more dynamic range, accuracy, and flexibility in any current sensing application.
AD8215 rev. 0 | page 12 of 16 applications information high-side current sensing with a low-side switch in such load control configurations, the pwm-controlled switch is ground referenced. an inductive load (solenoid) is tied to a power supply. a resistive shunt is placed between the switch and the load (see figure 28 ). 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 because shorts to ground can be detected with the shunt on the high side. in this circuit configuration, when the switch is closed, the common-mode 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. 07203-027 inductive load clamp diode shunt switch battery 5 4 5v 8 7 6 2 3 5 14 nc v+ in+ in? out ncnc gnd AD8215 figure 28. low-side switch high-side current sensing in this configuration, the shunt resistor is referenced to the battery. high voltage is present at the inputs of the current sense amplifier. in this mode, the recirculation current is again measured and shorts to ground can be detected. when the shunt is battery referenced, the AD8215 produces a linear ground-referenced analog output. an ad8214 can also be used to provide an over- current detection signal in as little as 100 ns (see figure 29 ). this feature is useful in high current systems where fast shutdown in over-current conditions is essential. 07203-028 5 4 5v inductive load clamp diode shunt switch battery 1 2 3 4 8 7 6 5 ad8214 gnd nc ?in out v reg +in v s nc overcurrent detection (<100ns) 5 6 7 3 2 8 41 nc v+ in+ in? out nc nc gnd AD8215 figure 29. battery-referenced shunt resistor low-side current sensing in systems where low-side current sensing is preferred, the AD8215 provides an integrated solution with great accuracy. ground noise is rejected, cmrr is typically higher than 90 db, and output linearity is not compromised, regardless of the input differential voltage. 07203-029 inductive load clamp diode shunt battery switch 5 4 5v 5 6 7 3 2 8 41 nc v+ in+ in? out nc nc gnd AD8215 figure 30. ground-referenced shunt resistor
AD8215 rev. 0 | page 13 of 16 outline dimensions 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. compliant to jedec standards ms-012-a a 012407-a 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 1.75 (0.0688) 1.35 (0.0532) seating plane 0.25 (0.0098) 0.10 (0.0040) 4 1 85 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) bsc 6.20 (0.2441) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122) coplanarity 0.10 figure 31. 8-lead standard small outline package [soic_n] narrow body (r-8) dimensions shown in millimeters and (inches) ordering guide model temperature range package description package option AD8215yrz 1 ?40c to +125c 8-lead soic_n r-8 AD8215yrz-rl 1 ?40c to +125c 8-lead soic_n, 13 tape and reel r-8 AD8215yrz-r7 1 ?40c to +125c 8-lead soic_n, 7 tape and reel r-8 1 z = rohs compliant part.
AD8215 rev. 0 | page 14 of 16 notes
AD8215 rev. 0 | page 15 of 16 notes
AD8215 rev. 0 | page 16 of 16 notes ?2008 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. d07203-0-1/08(0)

▲Up To Search▲

Price & Availability of AD8215

	To Download AD8215 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .