Current Transducer CASR series IPN = 6, 15, 25, 50 A Ref: CASR 6-NP, CASR 15-NP, CASR 25-NP, CASR 50-NP For the electronic measurement of current: DC, AC, pulsed..., with galvanic isolation between the primary and the secondary circuit. Features Applications Closed loop (compensated) multi-range AC variable speed and servo motor drives current transducer Static converters for DC motor drives Voltage output Battery supplied applications Single supply Uninterruptible Power Supplies (UPS) Isolated plastic case material recognized Switched Mode Power Supplies (SMPS) according to UL 94-V0 Power supplies for welding applications Compact design for PCB mounting. Solar inverters. Advantages Standards Very low temperature coefficient of offset EN 50178 Very good dv/dt immunity UL 508 LTSR compatible footprint IEC 61010-1 (safety). Reduced height Reference pin with two modes: Ref IN and Ref OUT Extended measuring range for unipolar measurement. Application Domain Industrial. Page 1/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Absolute maximum ratings Parameter Symbol Unit Value VC V 7 C 110 A 20 x IPN kV 4 Supply voltage Primary conductor temperature Maximum primary current IP max ESD rating, Human Body Model (HBM) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum ratings for extended periods may degrade reliability. Isolation characteristics Parameter Symbol Unit Value RMS voltage for AC isolation test 50/60Hz/1 min Vd kV 4.1 Impulse withstand voltage 1.2/50 s Vw kV 7.5 Partial discharge extinction voltage @ 10 pC (rms) Ve V 1000 Clearance distance (pri. - sec.) dCI mm 7.5 Shortest distance through air Creepage distance (pri. - sec.) dCp mm 7.5 Shortest path along device body Creepage distance (pri. .- sec.) dCp mm 6.2 When mounted on PCB with recommended layout - - V0 according to UL 94 CTI V 600 Application example - - Reinforced isolation, non 300 V CAT III uniform field according to PD2 EN 50178, EN 61010 Application example - - Simple isolation, non 600 V CAT III uniform field according to PD2 EN 50178, EN 61010 According to UL 508: primary potential involved in Volts RMS AC or DC - V Symbol Unit Min Ambient operating temperature TA C -40 85 Ambient storage temperature TS C -55 105 Mass m g Case material Comparative tracking index Comment For use in a pollution degree 2 environment 600 Environmental and mechanical characteristics Parameter Standards Typ Max Comment 9 EN 50178, IEC 60950-1, IEC 61010-1, IEC 61326-1, UL 508 Page 2/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Electrical data CASR 6-NP At TA = 25C, VC = + 5 V, NP = 1 turn, RL = 10 k, internal reference, unless otherwise noted. Parameter Max Comment Unit Primary nominal current rms IPN A Primary current, measuring range IPM A Number of primary turns NP - Supply voltage VC V Current consumption IC mA Reference voltage @ IP = 0 A VREF V 2.495 External reference voltage VREF V 0 4 Output voltage VOUT V 0.375 4.625 Output voltage @ IP = 0 A VOUT V Electrical offset voltage VOE mV -5.3 5.3 100% tested VOUT - VREF Electrical offset current referred to primary IOE mA -51 51 100% tested Temperature coefficient of VREF TCVREF ppm/K 5 50 Internal reference Temperature coefficient of VOUT @ IP = 0 A TCVOUT ppm/K 6 14 ppm/K of 2.5 V - 40C .. 85C Theoretical sensitivity Gth mV/A 104.2 Sensitivity error G % TCG ppm/K Linearity error L % of IPN -0.1 0.1 Magnetic offset current (10 x IPN) referred to primary IOM A -0.1 0.1 Output current noise (spectral density) rms 100 Hz .. 100 kHz referred to primary ino A/Hz1/2 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 40 Reaction time @ 10 % of IPN tra Response time @ 90 % of IPN Temperature coefficient of G Min Typ Symbol 6 -20 20 1,2,3 4.75 5 15 + IP (mA) NS 2.5 5.25 20 + IP (mA) NS 2.505 NS = 1731 turns Internal reference VREF -0.7 625 mV/ IPN 0.7 100% tested 40 - 40C .. 85C RL = 1 k 160 RL = 1 k s 0.3 RL = 1 k di/dt = 18 A/s tr s 0.3 RL = 1 k di/dt = 18 A/s Frequency bandwidth ( 1 dB) BW kHz 200 RL = 1 k Frequency bandwidth ( 3 dB) BW kHz 300 RL = 1 k Overall accuracy XG % of IPN 1.7 Overall accuracy @ TA = 85C XG % of IPN 2.2 Accuracy X % of IPN 0.8 Accuracy @ TA = 85C X % of IPN 1.4 Page 3/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Electrical data CASR 15-NP At TA = 25C, VC = + 5 V, NP = 1 turn, RL = 10 k, internal reference, unless otherwise noted. Parameter Max Comment Unit Primary nominal current rms IPN A Primary current, measuring range IPM A Number of primary turns NP - Supply voltage VC V Current consumption IC mA Reference voltage @ IP = 0 A VREF V 2.495 External reference voltage VREF V 0 4 Output voltage VOUT V 0.375 4.625 Output voltage @ IP = 0 A VOUT V Electrical offset voltage VOE mV -2.21 2.21 100% tested VOUT - VREF Electrical offset current referred to primary IOE mA -53 53 100% tested Temperature coefficient of VREF TCVREF ppm/K 5 50 Internal reference Temperature coefficient of VOUT @ IP = 0 A TCVOUT ppm/K 2.3 6 ppm/K of 2.5 V - 40C .. 85C Theoretical sensitivity Gth mV/A 41.67 Sensitivity error G % TCG ppm/K Linearity error L % of IPN -0.1 0.1 Magnetic offset current (10 x IPN) referred to primary IOM A -0.1 0.1 Output current noise (spectral density) rms 100 Hz .. 100 kHz referred to primary ino A/Hz1/2 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 15 Reaction time @ 10 % of IPN tra Response time @ 90 % of IPN Temperature coefficient of G Min Typ Symbol 15 -51 51 1,2,3 4.75 5 15 + IP (mA) NS 2.5 5.25 20 + IP (mA) NS 2.505 NS = 1731 turns Internal reference VREF -0.7 625 mV/ IPN 0.7 100% tested 40 - 40C .. 85C RL = 1 k 60 RL = 1 k s 0.3 RL = 1 k di/dt = 44 A/s tr s 0.3 RL = 1 k di/dt = 44 A/s Frequency bandwidth ( 1 dB) BW kHz 200 RL = 1 k Frequency bandwidth ( 3 dB) BW kHz 300 RL = 1 k Overall accuracy XG % of IPN 1.2 Overall accuracy @ TA = 85C XG % of IPN 1.5 Accuracy X % of IPN 0.8 Accuracy @ TA = 85C X % of IPN 1.2 Page 4/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Electrical data CASR 25-NP At TA = 25C, VC = + 5 V, NP = 1 turn, RL = 10 k, internal reference, unless otherwise noted. Parameter Max Comment Unit Primary nominal current rms IPN A Primary current, measuring range IPM A Number of primary turns NP - Supply voltage VC V Current consumption IC mA Reference voltage @ IP = 0 A VREF V 2.495 External reference voltage VREF V 0 4 Output voltage VOUT V 0.375 4.625 Output voltage @ IP = 0 A VOUT V Electrical offset voltage VOE mV -1.35 1.35 100% tested VOUT - VREF Electrical offset current referred to primary IOE mA -54 54 100% tested Temperature coefficient of VREF TCVREF ppm/K 5 50 Internal reference Temperature coefficient of VOUT @ IP = 0 A TCVOUT ppm/K 1.4 4 ppm/K of 2.5 V - 40C .. 85C Theoretical sensitivity Gth mV/A 25 Sensitivity error G % TCG ppm/K Linearity error L % of IPN -0.1 0.1 Magnetic offset current (10 x IPN) referred to primary IOM A -0.1 0.1 Output current noise (spectral density) rms 100 Hz .. 100 kHz referred to primary ino A/Hz1/2 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 10 Reaction time @ 10 % of IPN tra Response time @ 90 % of IPN Temperature coefficient of G Min Typ Symbol 25 -85 85 1,2,3 4.75 5 15 + 5.25 IP (mA) I (mA) 20 + P NS NS 2.5 2.505 NS = 1731 turns Internal reference VREF -0.7 625 mV/ IPN 0.7 100% tested 40 - 40C .. 85C RL = 1 k 40 RL = 1 k s 0.3 RL = 1 k di/dt = 68 A/s tr s 0.3 Frequency bandwidth ( 1 dB) BW kHz 200 RL = 1 k Frequency bandwidth ( 3 dB) BW kHz 300 RL = 1 k Overall accuracy XG % of IPN 1 Overall accuracy @ TA = 85C XG % of IPN 1.35 Accuracy X % of IPN 0.8 Accuracy @ TA = 85C X % of IPN 1.15 RL = 1 k di/dt = 68 A/s Page 5/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Electrical data CASR 50-NP At TA = 25C, VC = + 5 V, NP = 1 turn, RL = 10 k, internal reference, unless otherwise noted. Parameter Max Comment Unit Primary nominal current rms IPN A Primary current, measuring range IPM A Number of primary turns NP - Supply voltage VC V Current consumption IC mA Reference voltage @ IP = 0 A VREF V 2.495 External reference voltage VREF V 0 4 Output voltage VOUT V 0.375 4.625 Output voltage @ IP = 0 A VOUT V Electrical offset voltage VOE mV -0.725 0.725 100% tested VOUT - VREF Electrical offset current referred to primary IOE mA -58 58 100% tested Temperature coefficient of VREF TCVREF ppm/K 5 50 Internal reference Temperature coefficient of VOUT @ IP = 0 A TCVOUT ppm/K 0.7 3 ppm/K of 2.5 V - 40C .. 85C Theoretical sensitivity Gth mV/A 12.5 Sensitivity error G % TCG ppm/K Linearity error L % of IPN -0.1 0.1 Magnetic offset current (10 x IPN) referred to primary IOM A -0.1 0.1 Output current noise (spectral density) rms 100 Hz .. 100 kHz referred to primary ino A/Hz1/2 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (Typ.) - mV 5 Reaction time @ 10 % of IPN tra Response time @ 90 % of IPN Temperature coefficient of G Min Typ Symbol 50 -150 150 1,2,3 4.75 5 15 + 5.25 IP (mA) I (mA) 20 + P NS NS 2.5 2.505 NS = 966 turns Internal reference VREF -0.7 625 mV/ IPN 0.7 100% tested 40 - 40C .. 85C RL = 1 k 20 RL = 1 k s 0.3 RL = 1 k di/dt = 100 A/s tr s 0.3 RL = 1 k di/dt = 100 A/s Frequency bandwidth ( 1 dB) BW kHz 200 RL = 1 k Frequency bandwidth ( 3 dB) BW kHz 300 RL = 1 k Overall accuracy XG % of IPN 0.9 Overall accuracy @ TA = 85C XG % of IPN 1.2 Accuracy X % of IPN 0.8 Accuracy @ TA = 85C X % of IPN 1.1 Page 6/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series 0 -0.05 -0.1 -6 0 IP (A) Figure 1: Linearity error 1000 10000 100000 1000000 Frequency (Hz) Figure 2: Frequency response 3.2 7 3.2 6 3.1 6 3.1 3.0 5 3.0 2.9 4 IP = 6 A 3 2.8 IP (A) 4 VOUT (V) 7 5 IP (A) Relative Sensitivity Phase 100 6 3 2.8 IP 2.7 2.6 1 VOUT 2.6 0 2.5 0 -1 2.4 -1 VOUT -0.5 0 0.5 1 1.5 2.5 2.4 -2 2 0 2 4 6 8 10 t (s) t (s) Figure 3: Step response Figure 4: Step response 10000 Primary Voltage VP (V) 800 1000 100 10 3.6 600 3.4 400 3.2 200 0 -200 VP VOUT VREF -400 1 3.0 20 kV/s 2.8 2.6 -600 -800 0.1 1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 Frequency (Hz) Figure 5: Input referred noise VOUT (V) 2.7 IP 1 1/2 2.9 IP = 6 A 2 2 ino (A/Hz ) 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 6 A VOUT (V) 0.05 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 Phase () 0.1 Relative Sensitivity (dB) Linearity error (% of IPN) Typical performance characteristics CASR 6-NP 2.4 -1 0 1 2 3 4 5 t (s) Figure 6: dv/dt Page 7/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Relative Sensitivity (dB) 0 -0.05 -0.1 -15 0 IP (A) Relative Sensitivity Phase 100 15 Figure 7: Linearity error 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 15 A 1000 10000 100000 1000000 Frequency (Hz) Figure 8: Frequency response 3.2 15 3.1 15 3.1 12.5 3.0 12.5 3.0 10 2.9 10 IP = 15 A 7.5 5 2.5 2.8 IP 2.7 VOUT 2.6 IP (A) 17.5 VOUT (V) 3.2 IP (A) 17.5 7.5 5 2.5 2.8 IP 2.7 VOUT 2.6 0 2.5 0 2.5 -2.5 2.4 -2.5 2.4 -0.5 0 0.5 1 1.5 2 -2 0 2 t (s) Figure 9: Step response 4 6 8 10 t (s) Figure 10: Step response 800 Primary Voltage VP (V) 10000 1000 ino (A/Hz1/2) 2.9 IP = 15 A 100 10 3.6 600 3.4 400 3.2 200 0 3.0 20 kV/s -200 VP VOUT VREF -400 1 2.8 2.6 -600 -800 0.1 1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 2.4 -1 0 Frequency (Hz) Figure 11: Input referred noise VOUT (V) 0.05 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 VOUT (V) Linearity error (% of IPN) 0.1 Phase () Typical performance characteristics CASR 15-NP 1 2 3 4 5 t (s) Figure 12: dv/dt Page 8/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Typical performance characteristics CASR 25-NP Relative Sensitivity (dB) -0.05 -0.1 -25 0 25 Relative Sensitivity Phase 100 1000 10000 100000 1000000 Frequency (Hz) IP (A) Figure 13: Linearity error Figure 14: Frequency response 3.2 29.2 3.2 25.0 3.1 25.0 3.1 20.8 3.0 20.8 16.7 2.9 3.0 16.7 2.8 12.5 IP 2.7 VOUT 8.3 2.6 IP 2.7 4.2 4.2 VOUT 0.0 2.5 2.6 -4.2 2.4 0.0 0 0.5 1 1.5 2.5 -4.2 2 2.4 -2 0 2 t (s) 4 6 8 10 t (s) Figure 15: Step response Figure 16: Step response 800 Primary Voltage VP (V) 10000 1000 1/2 2.8 8.3 -0.5 ino (A/Hz ) 2.9 IP = 25 A IP (A) IP (A) IP = 25 A 12.5 VOUT (V) 29.2 100 10 3.6 600 3.4 400 3.2 200 0 3.0 20 kV/s -200 VP VOUT VREF -400 1 2.8 2.6 -600 -800 0.1 1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 Frequency (Hz) Figure 17: Input referred noise VOUT (V) 0 VOUT (V) Linearity error (% of IPN) 0.05 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 25 A Phase () 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0.1 2.4 -1 0 Figure 18: dv/dt 1 2 3 4 5 t (s) Page 9/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Typical performance characteristics CASR 50-NP Relative Sensitivity (dB) 0 -0.05 -0.1 -50 0 Relative Sensitivity Phase 100 50 1000 10000 100000 1000000 Frequency (Hz) IP (A) Figure 19: Linearity error Figure 20: Frequency response 3.2 58.3 3.2 50.0 3.1 50.0 3.1 41.7 3.0 41.7 3.0 2.9 33.3 25.0 16.7 8.3 2.8 2.6 8.3 2.5 0.0 2.4 -8.3 -8.3 -0.5 0 0.5 1 16.7 2.7 VOUT 0.0 1.5 IP = 50 A 25.0 IP 2 4 10000 800 Primary Voltage VP (V) Figure 22: Step response ino (A/Hz1/2) 10 2.6 6 8 10 3.6 600 3.4 400 3.2 200 0 3.0 20 kV/s -200 VP VOUT VREF -400 1 2.7 VOUT t (s) Figure 21: Step response 100 IP 2.4 0 t (s) 1000 2.8 2.5 -2 2 2.9 VOUT (V) IP (A) IP = 50 A IP (A) 33.3 VOUT (V) 58.3 2.8 2.6 -600 -800 0.1 1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 2.4 -1 0 1 2 3 4 5 t (s) Frequency (Hz) Figure 23: Input referred noise VOUT (V) Linearity error (% of IPN) 0.05 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 50 A Phase () 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0.1 Figure 24: dv/dt Page 10/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Maximum continuous DC primary current 40 35 90 80 CASR 6-NP 25 IP (A) IP (A) 30 20 15 10 CASR 15-NP 70 60 50 40 30 20 5 10 0 0 0 20 40 60 80 100 120 0 20 40 100 120 Figure 26: IP vs TA for CASR 15-NP 90 160 80 70 140 CASR 50-NP 120 CASR 25-NP IP (A) IP (A) 80 TA (C) TA (C) Figure 25: IP vs TA for CASR 6-NP 60 50 40 30 60 100 80 60 40 20 10 0 20 0 0 20 40 60 80 100 120 0 20 40 TA (C) 60 80 100 120 TA (C) Figure 27: IP vs TA for CASR 25-NP Figure 28: IP vs TA for CASR 50-NP The maximum continuous DC primary current plot shows the boundary of the area for which all the following conditions are true: -- IP < IPM -- Junction temperature Tj < 125 C -- Primary conductor temperature < 110 C -- Resistor power dissipation < 0.5 x rated power Frequency derating AC Derating max RMS AC current / max DC current 1.25 1 0.75 0.5 0.25 0 10 100 1k 10k 100k 1M f (Hz) Figure 29: Maximum RMS AC primary current / maximum DC primary current vs frequency 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice Page 11/18 www.lem.com CASR series Performance parameters definition Ampere-turns and amperes Sensitivity and linearity The transducer is sensitive to the primary current linkage QP (also called ampere-turns). To measure sensitivity and linearity, the primary current (DC) is cycled from 0 to IP, then to -IP and back to 0 (equally spaced IP/10 steps). The sensitivity G is defined as the slope of the linear regression line for a cycle between IPN. QP=NPIP(At) Where NPIP the number of primary turn (1, 2 or 3 depending on the connection of the primary jumpers) Caution: As most applications will use the transducer with only one single primary turn (NP = 1), much of this datasheet is written in terms of primary current instead of current linkages. However, the ampere-turns (A-t) unit is used to emphasis that current linkages are intended and applicable. Transducer simplified model The static model of the transducer at temperature TA is: VOUT = G QP + error The linearity error L is the maximum positive or negative difference between the measured points and the linear regression line, expressed in % of IPN. Magnetic offset The magnetic offset current IOM is the consequence of a current on the primary side ("memory effect" of the transducer's ferro-magnetic parts). It is included in the linearity figure but can be measured individually. It is measured using the following primary current cycle. IOM depends on the current value IP1. I In which error = VOE + VOT (TA) + G *QP*G + L(QPmax)*QPmax*G + TCG*(TA-25)*QP*G With: QP = NPIP QPmax VOUT TA VOE VOT(TA) G G L (QPmax) :the input ampere-turns (At) Please read above warning. :the maxi input ampere-turns that have been applied to the transducer (At) :the secondary voltage (V) :the ambient temperature (C) :the electrical offset voltage (V) :the temperature variation of VO at temperature TA (V) :the sensitivity of the transducer (V/At) :the sensitivity error :the linearity error for QPmax This model is valid for primary ampere-turns QP between -QPmax and +QPmax only. OM = V (t ) - V (t ) 1 2 Gth OUT 1 OUT 2 IP (DC) IP1 0A -IP1 t t1 Ip(3) t2 Ip(t 3) Figure 30: Current cycle used to measure magnetic and electrical offset (transducer supplied) Page 12/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Performance parameters definition (continued) Electrical offset Overall accuracy The electrical offset voltage VOE can either be measured when the ferro-magnetic parts of the transducer are: The overall accuracy at 25C XG is the error in the - IPN .. + IPN range, relative to the rated value IPN. It includes: the electrical offset VOE the sensitivity error eG the linearity error eL (to IPN) The magnetic offset is part of the overall accuracy. It is taken into account in the linearity error figure provided the transducer has not been magnetized by a current higher than IPN. completely demagnetized, which is difficult to realize, or in a known magnetization state, like in the current cycle shown in figure 30. Using the current cycle shown in figure 30, the electrical offset is: V = OE V (t ) + V (t ) 2 OUT 1 OUT 2 The temperature variation VOT of the electrical offset voltage VOE is the variation of the electrical offset from 25C to the considered temperature: V (T ) = V (T ) - V (25C ) OT OE OE Note: the transducer has to be demagnetized prior to the application of the current cycle (for example with a demagnetization tunnel). Response and reaction times The response time tr and the reaction time tra are shown in figure 31. Both depend on the primary current di/dt. They are measured at nominal ampere-turns. 100 % 90 % 10 9 8 I VOUT Ip tr 10 % tra 1 2 3 Figure 31: Test connection t Figure 32: Response time tr and reaction time tra Page 13/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Application information Filtering and decoupling Supply voltage VC Reference VREF The fluxgate oscillator draws current pulses of up to 30 mA at a rate of ca. 900 kHz. Significant 900 kHz voltage ripple on VC can indicate a power supply with high impedance. At these frequencies the power supply rejection ratio is low, and the ripple may appear on the transducer output VOUT and reference VREF. The transducer has internal decoupling capacitors, but in the case of a power supply with high impedance, it is advised to provide local decoupling (100 nF or more, located close to the transducer) Ripple present on the reference output can be filtered with a low value of capacitance because of the internal 680 Ohm series resistance. The maximum filter capacitance value is 1 F.Application information 10 9 8 Output VOUT The output VOUT has a very low output impedance of typically 2 Ohms; it can drive 100 pF directly. Adding series Rf = 100 Ohms allows much larger capacitive loads. Empirical evaluation may be necessary to obtain optimum results. The minimum load resistance on VOUT is 1 kOhm. 1 2 3 Total Primary Resistance The primary resistance is 0.72 m per conductor. In the following table, examples of primary resistance according to the number of primary turns. Number of primary turns Primary resistance RP [mW] 1 0.24 Recommended connections IN 2 9 8 OUT 1 10 2 9 3 8 OUT 1 10 2 9 3 8 OUT 1 2 3 1.08 IN 3 10 2.16 IN Page 14/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series Application information (continued) External reference voltage If the Ref pin of the transducer is not used it could be either left unconnected or filtered according to the previous paragraph "Reference VREF". The Ref pin has two modes Ref IN and Ref OUT: In the Ref OUT mode the 2.5 V internal precision reference is used by the transducer as the reference point for bipolar measurements; this internal reference is connected to the Ref pin of the transducer through a 680 Ohms resistor. it tolerates sink or source currents up to 5 mA, but the 680 Ohms resistor prevents this current to exceed these limits. In the Ref IN mode, an external reference voltage is connected to the Ref pin; this voltage is specified in the range 0 to 4 V and is directly used by the transducer as the reference point for measurements. The external reference voltage Vref must be able: - either to source a typical current of - or to sink a typical current of Vref - 2.5 , the maximum value will be 2.2 mA typ. when Vref = 4 V. 680 2.5 - Vref 680 , the maximum value will be 3.68 mA typ. when Vref = 0 V. 50 40 30 20 10 0 -10 -20 -30 -40 -50 I P (A) I P (A) The following graphs show how the measuring range of each transducer version depends on the external reference voltage value Vref. CASR 6 0 1 2 VREF (V) 3 Upper limit : IP = -9.6 * Vref + 44.4 (Vref = 0 .. 4 V) Lower limit : IP = -9.6 * Vref + 3.6 (Vref = 0 .. 4 V) 4 100 80 60 40 20 0 -20 -40 -60 -80 -100 CASR 15 0 1 2 VREF (V) Upper limit : IP = -24 * Vref + 111 Upper limit : IP = 80 Lower limit : IP = -24 * Vref + 9 Lower limit : IP = -80 3 4 (Vref = 1.29 .. 4 V) (Vref = 0 .. 1.29 V) (Vref = 0 .. 3.7 V) (Vref = 3.7 .. 4 V) Page 15/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series 200 100 80 60 40 20 0 -20 -40 -60 -80 -100 150 100 I P (A) I P (A) External reference voltage (continued) 50 0 -50 -100 -150 CASR 25 0 CASR 50 -200 1 2 VREF (V) Upper limit : IP = -40 * Vref + 185 Upper limit : IP = 85 Lower limit : IP = -40 * Vref + 15 Lower limit : IP = -85 3 4 (Vref = 2.5 .. 4 V) (Vref = 0 .. 2.5 V) (Vref = 0 .. 2.5 V) (Vref = 2.5 .. 4 V) 0 1 2 VREF (V) Upper limit : IP = -80 * Vref + 370 Upper limit : IP = 150 Lower limit : IP = -80 * Vref + 30 Lower limit : IP = -150 3 4 (Vref = 2.75 .. 4 V) (Vref = 0 .. 2.75 V) (Vref = 0 .. 2.25 V) (Vref = 2.25 .. 4 V) Example with VREF = 1.65 V: The 6 A version has a measuring range from - 12.24 A to + 28.5 A The 15 A version has a measuring range from - 30.6 A to + 71.4 A The 25 A version has a measuring range from - 51 A to + 85 A The 50 A version has a measuring range from - 102 A to + 150 A Example with VREF = 0 V: The 6 A version has a measuring range from + 3.6 A to + 44.4 A The 15 A version has a measuring range from + 9 A to + 80 A The 25 A version has a measuring range from + 15 A to + 85 A The 50 A version has a measuring range from + 30 A to + 150 A Page 16/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CASR series CASR Series, PCB footprint Assembly on PCB Recommended PCB hole diameter 1.3 mm for primary pin 0.8 mm for secondary pin Maximum PCB thickness 2.4 mm Wave soldering profile maximum 260C for 10 s No clean process only. Safety This transducer must be used in limited-energy secondary circuits according to IEC 61010-1. This transducer must be used in electric/electronic equipment with respect to applicable standards and safety requirements in accordance with the manufacturer's operating instructions. Caution, risk of electrical shock When operating the transducer, certain parts of the module can carry hazardous voltage (eg. primary busbar, power supply). Ignoring this warning can lead to injury and/or cause serious damage. This transducer is a build-in device, whose conducting parts must be inaccessible after installation. A protective housing or additional shield could be used. Main supply must be able to be disconnected. 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice Page 17/18 www.lem.com CASR series Dimensions CASR Series (in mm. General linear tolerance 0.25 mm) Connection Page 18/18 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com