Current Transducer CKSR series IPN = 6, 15, 25, 50 A Ref: CKSR 6-NP, CKSR 15-NP, CKSR 25-NP, CKSR 50-NP For the electronic measurement of current: DC, AC, pulsed..., with galvanic separation 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) ●● Compact design for PCB mounting. ●● Switched Mode Power Supplies (SMPS) ●● Power supplies for welding applications Advantages ●● Very low temperature coefficient of offset ●● Solar inverters. ●● Very good dv/dt immunity Standards ●● Higher creepage distance / clearance ●● EN 50178: 1997 ●● Reduced height ●● IEC 60950-1: 2006 ●● Reference pin with two modes: Ref in and Ref out ●● IEC 61010-1: 2010 ●● Extended measuring range for unipolar measurement. ●● IEC 61326-1: 2012 ●● UL 508: 2010. Application Domain ●● Industrial. N°97.E7.09.000.7, N°97.E7.15.000.7, N°97.E7.19.000.7, N°97.E7.25.000.7 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice Page 1/19 www.lem.com CKSR series Absolute maximum ratings Parameter Symbol Unit Value Supply voltage UC V 7 Primary conductor temperature TB °C 110 Maximum primary current IP max A 20 × IPN EDS rating, Human Body Model (HBM) UESD kV 4 Stresses above these ratings may cause permanent damage. Exposure to absolute maximum ratings for extended periods may degrade reliability. UL 508: Ratings and assumptions of certification File # E189713 Volume: 2 Section: 1 Standards ●● CSA C22.2 NO. 14-10 INDUSTRIAL CONTROL EQUIPMENT - Edition 11 - Revision Date 2011/08/01 ●● UL 508 STANDARD FOR INDUSTRIAL CONTROL EQUIPMENT - Edition 17 - Revision Date 2010/04/15 Ratings Parameter Symbol Primary involved potential Unit Value V AC/DC 1000 Max surrounding air temperature TA °C 105 Primary current IP A According to series primary currents Secondary supply voltage UC V DC 7 Output voltage Vout V 0 to 5 Conditions of acceptability When installed in the end-use equipment, consideration shall be given to the following: 1 - These devices must be mounted in a suitable end-use enclosure. 4 - CKSR series intended to be mounted on the printed circuit wiring board of the end-use equipment (with a minimum CTI of 100). 5 - CKSR series shall be used in a pollution degree 2. 8 - Low voltage circuits are intended to be powered by a circuit derived from an isolating source (such as transformer, optical isolator, limiting impedance or electro-mechanical relay) and having no direct connection back to the primary circuit (other than through the grounding means). 11 - CKSR series: based on results of temperature tests, in the end-use application, a maximum of 100°C cannot be exceeded at soldering joint between primary coil pin and soldering point (corrected to the appropriate evaluated max. surrounding air). Marking Only those products bearing the UL or UR Mark should be considered to be Listed or Recognized and covered under UL's Follow-Up Service. Always look for the Mark on the product. Page 2/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Insulation coordination Parameter Symbol Unit Value Rms voltage for AC insulation test, 50 Hz, 1 min Ud kV 4.3 Impulse withstand voltage 1.2/50 µs ÛW kV 8 Partial discharge extinction rms voltage @ 10 pC Ue V 1000 Clearance (pri. - sec.) dCI mm 8.2 Shortest distance through air Creepage distance (pri. - sec.) dCp mm 8.2 Shortest internal path along device body - - V0 according to UL 94 CTI V 600 Application example - - 300 V CAT III PD2 Reinforced insulation, non uniform field according to EN 61010 Application example - - 600 V CAT III PD2 Reinforced insulation, non uniform field according to EN 50178 Application example - - 1000 V CAT III PD2 Simple insulation, non uniform field according to EN 50178 Symbol Unit Min Ambient operating temperature TA °C -40 105 Ambient storage temperature TS °C -55 105 Mass m g Case material Comparative tracking index Comment Environmental and mechanical characteristics Parameter Typ Max Comment 9 Page 3/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Electrical data CKSR 6-NP At TA = 25 °C, UC = + 5 V, NP = 1 turn, RL = 10 kΩ internal reference unless otherwise noted (see Min, Max, typ. definition paragraph in page 13). Parameter Typ Comment Unit Primary nominal rms current IPN A Primary current, measuring range IPM A Number of primary turns NP Supply voltage UC 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 -40 °C .. 105 °C (at ± 6 Sigma) Theoretical sensitivity Gth mV/A 104.2 Sensitivity error εG % TCG ppm/K εL % of IPN -0.1 0.1 Magnetic offset current (10 × IPN) referred to primary IOM A -0.1 0.1 Output rms current noise (spectral density) 100 Hz .. 100 kHz referred to primary Ino µA/Hz½ 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 40 Reaction time @ 10 % of IPN tra Step response time to 90 % of IPN Temperature coefficient of G Linearity error Min Max Symbol Apply derating according to fig. 25 6 -20 20 1,2,3,4 4.75 5 15 + 5.25 I (mA) N S I (mA) N 2.5 2.505 p 20 + p S NS = 1731 turns Internal reference Vref -0.7 625 mV/ IPN 0.7 100% tested ±40 -40 °C .. 105 °C RL = 1 kΩ 160 RL = 1 kΩ µs 0.3 RL = 1 kΩ, di/dt = 18 A/µs tr µs 0.3 RL = 1 kΩ, di/dt = 18 A/µs Frequency bandwidth (± 1 dB) BW kHz 200 RL = 1 kΩ Frequency bandwidth (± 3 dB) BW kHz 300 RL = 1 kΩ Overall accuracy XG % of IPN 1.7 Overall accuracy @ TA = 85 °C (105 °C) XG % of IPN 2.2 (2.4) Accuracy X % of IPN 0.8 Accuracy @ TA = 85 °C (105 °C) X % of IPN 1.4 (1.6) Page 4/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Electrical data CKSR 15-NP At TA = 25 °C, UC = + 5 V, NP = 1 turn, RL = 10 kΩ internal reference unless otherwise noted (see Min, Max, typ. definition paragraph in page 13). Parameter Typ Comment Unit Primary nominal rms current IPN A Primary current, measuring range IPM A Number of primary turns NP Supply voltage UC 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 -40 °C .. 105 °C (at ± 6 Sigma) Theoretical sensitivity Gth mV/A 41.67 Sensitivity error εG % TCG ppm/K εL % of IPN -0.1 0.1 Magnetic offset current (10 × IPN) referred to primary IOM A -0.1 0.1 Output rms current noise (spectral density) 100 Hz.. 100 kHz referred to primary Ino µA/Hz½ 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 15 Reaction time @ 10 % of IPN tra Step response time to 90 % of IPN Temperature coefficient of G Linearity error Min Max Symbol Apply derating according to fig. 26 15 -51 51 1,2,3,4 4.75 5 15 + 5.25 I (mA) N S I (mA) N 2.5 2.505 p 20 + p S NS = 1731 turns Internal reference Vref -0.7 625 mV/ IPN 0.7 100% tested ±40 -40 °C .. 105 °C RL = 1 kΩ 60 RL = 1 kΩ µs 0.3 RL = 1 kΩ, di/dt = 44 A/µs tr µs 0.3 RL = 1 kΩ, di/dt = 44 A/µs Frequency bandwidth (± 1 dB) BW kHz 200 RL = 1 kΩ Frequency bandwidth (± 3 dB) BW kHz 300 RL = 1 kΩ Overall accuracy XG % of IPN 1.2 Overall accuracy @ TA = 85 °C (105 °C) XG % of IPN 1.5 (1.7) Accuracy X % of IPN 0.8 Accuracy @ TA = 85 °C (105 °C) X % of IPN 1.2 (1.3) Page 5/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Electrical data CKSR 25-NP At TA = 25 °C, UC = + 5 V, NP = 1 turn, RL = 10 kΩ internal reference unless otherwise noted (see Min, Max, typ. definition paragraph in page 13). Parameter Typ Comment Unit Primary nominal rms current IPN A Primary current, measuring range IPM A Number of primary turns NP Supply voltage UC 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 -40 °C .. 105 °C (at ± 6 Sigma) Theoretical sensitivity Gth mV/A 25 Sensitivity error εG % TCG ppm/K εL % of IPN -0.1 0.1 Magnetic offset current (10 × IPN) referred to primary IOM A -0.1 0.1 Output rms current noise (spectral density) 100 Hz.. 100 kHz referred to primary Ino µA/Hz½ 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 10 Reaction time @ 10 % of IPN tra Step response time to 90 % of IPN Temperature coefficient of G Linearity error Min Max Symbol Apply derating according to fig. 27 25 -85 85 1,2,3,4 4.75 5 15 + 5.25 S I (mA) N 2.5 2.505 I (mA) N p 20 + p S NS = 1731 turns Internal reference Vref -0.7 625 mV/ IPN 0.7 100% tested ±40 -40 °C .. 105 °C RL = 1 kΩ 40 RL = 1 kΩ µs 0.3 RL = 1 kΩ, di/dt = 68 A/µs tr µs 0.3 RL = 1 kΩ, di/dt = 68 A/µs Frequency bandwidth (± 1 dB) BW kHz 200 RL = 1 kΩ Frequency bandwidth (± 3 dB) BW kHz 300 RL = 1 kΩ Overall accuracy XG % of IPN 1 Overall accuracy @ TA = 85 °C (105 °C) XG % of IPN 1.35 (1.45) Accuracy X % of IPN 0.8 Accuracy @ TA = 85 °C (105 °C) X % of IPN 1.15 (1.25) Page 6/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Electrical data CKSR 50-NP At TA = 25 °C, UC = + 5 V, NP = 1 turn, RL = 10 kΩ internal reference unless otherwise noted (see Min, Max, typ. definition paragraph in page 13). Parameter Typ Comment Unit Primary nominal rms current IPN A Primary current, measuring range IPM A Number of primary turns NP Supply voltage UC 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 -40 °C .. 105 °C (at ± 6 Sigma) Theoretical sensitivity Gth mV/A 12.5 Sensitivity error εG % TCG ppm/K εL % of IPN -0.1 0.1 Magnetic offset current (10 × IPN) referred to primary IOM A -0.1 0.1 Output rms current noise (spectral density) 100 Hz .. 100 kHz referred to primary Ino µA/Hz½ 20 Peak-peak output ripple at oscillator frequency f = 450 kHz (typ.) - mV 5 Reaction time @ 10 % of IPN tra Step response time to 90 % of IPN Temperature coefficient of G Linearity error Min Max Symbol Apply derating according to fig. 28 50 -150 150 1,2,3,4 4.75 5 15 + 5.25 I (mA) N p S 2.5 20 + I (mA) N p S 2.505 NS = 966 turns Internal reference Vref -0.7 625 mV/ IPN 0.7 100% tested ±40 -40 °C .. 105 °C RL = 1 kΩ 20 RL = 1 kΩ µs 0.3 RL = 1 kΩ, di/dt = 100 A/µs tr µs 0.3 RL = 1 kΩ, di/dt = 100 A/µs Frequency bandwidth (± 1 dB) BW kHz 200 RL = 1 kΩ Frequency bandwidth (± 3 dB) BW kHz 300 RL = 1 kΩ Overall accuracy XG % of IPN 0.9 Overall accuracy @ TA = 85 °C (105 °C) XG % of IPN 1.2 (1.3) Accuracy X % of IPN 0.8 Accuracy @ TA = 85 °C (105 °C) X % of IPN 1.1 (1.3) Page 7/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series 0.05 0 -0.05 -0.1 -6 0 IP (A) 6 Relative Sensitivity Phase 1000 10000 100000 1000000 Frequency (Hz) 3.2 6 3.1 6 3.1 5 3.0 5 3.0 4 2.9 4 2.8 2 IP 2.7 1 Vout 2.6 2.8 2 IP 2.7 1 Vout 2.6 0 2.5 0 2.5 -1 2.4 -1 2.4 0 0.5 1 1.5 2 -2 0 2 t (µs) 4 6 8 10 t (µs) Figure 3: Step response Figure: 4 Step response 10000 Primary Voltage V P (V) 800 1000 ½ 2.9 IP = 6 A 3 100 10 3.6 600 3.4 400 3.2 200 0 ref -200 -400 1 3.0 20 kV/μs -600 Vp Vout Vref 2.8 2.6 -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) IP = 6 A 3 IP (A) 7 Vout (V) 3.2 Vout (V) Figure 2: Frequency response 7 -0.5 Ino (μA/Hz ) 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 6 A 100 Figure 1: Linearity error IP (A) 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 CKSR 6-NP 2.4 -1 0 1 2 3 4 5 t (µs) Figure 6: dv/dt Page 8/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series 0.05 0 -0.05 -0.1 0 IP (A) 15 15 12.5 10 IP = 15 A 7.5 5 2.5 3.1 15 3.1 3.0 12.5 3.0 2.9 10 7.5 Vout 2.6 2.5 2.5 0 2.5 2.4 -2.5 2.4 1.5 5 2 Figure 9: Step response 2.7 IP Vout -2 0 2 4 6 8 2.6 10 t (µs) Figure 10: Step response 800 Primary Voltage V P (V) 10000 1000 100 10 3.6 600 3.4 400 3.2 200 0 Vp Vout Vref -400 1 3.0 20 kV/μs -200 i ½ 2.8 2.7 t (µs) Ino (μA/Hz ) 2.9 IP = 15 A IP -2.5 1 3.2 2.8 0 0.5 17.5 Vout (V) IP (A) 3.2 2.8 2.6 -600 0.1 -800 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) Figure 8: Frequency response 17.5 0 1000 10000 100000 1000000 Frequency (Hz) Vout (V) Figure 7: Linearity error -0.5 Relative Sensitivity Phase 100 IP (A) -15 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 IP = 15 A Phase (°) 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0.1 Relative Sensitivity (dB) Linearity error (% of IPN) Typical performance characteristics CKSR 15-NP 1 2 3 4 5 t (µs) Figure 12: dv/dt Page 9/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Typical performance characteristics CKSR 25-NP Relative Sensitivity (dB) 0 -0.05 -0.1 -25 0 Relative Sensitivity Phase 100 25 1000 10000 100000 1000000 Frequency (Hz) IP (A) Figure 14: Frequency response 29.2 3.2 25.0 3.1 25.0 3.1 20.8 3.0 20.8 3.0 2.9 16.7 16.7 IP (A) IP = 25 A 12.5 2.8 IP Vout 8.3 4.2 -4.2 -0.5 0 0.5 1 1.5 2.7 2.6 4.2 Vout 2.6 2.5 0.0 2.4 -4.2 2.5 2.4 -2 2 0 2 4 6 8 10 t (µs) Figure 15: Step response Figure 16: Step response 800 Primary Voltage V P (V) 10000 1000 ½ 2.8 IP t (µs) Ino (μA/Hz ) 2.9 IP = 25 A 12.5 8.3 2.7 0.0 IP (A) 3.2 Vout (V) 29.2 100 10 3.6 600 3.4 400 3.2 200 0 3.0 20 kV/μs -200 VP Vout Vref -400 1 -600 2.8 2.6 -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 17: Input referred noise Vout (V) Figure 13: Linearity error 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 1 2 3 4 5 t (µs) Figure 18: dv/dt Page 10/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Typical performance characteristics CKSR 50-NP Relative Sensitivity (dB) 0 -0.05 -0.1 -50 0 50 Relative Sensitivity Phase 100 1000 10000 100000 1000000 Frequency (Hz) IP (A) 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 2.8 25.0 16.7 IP 2.7 8.3 Vout 2.6 8.3 2.5 0.0 2.4 -8.3 -8.3 -0.5 0 0.5 1 1.5 2 VoutI 16.7 2 10 4 8 10 800 3.6 600 3.4 400 3.2 200 0 3.0 20 kV/μs -200 VP Vout Vref -400 1 6 Figure 22: Step response Primary Voltage V P (V) ½ Ino (μA/Hz ) 100 2.6 t (µs) 10000 1000 2.7 2.4 0 t (µs) Figure 21: Step response 2.8 IP Vout 2.5 -2 I 0.0 2.9 IP = 50 A V IP (A) IP = 50 A IP (A) 33.3 Vout (V) 58.3 2.8 2.6 -600 2.4 -800 0.1 1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 -1 0 1 2 3 4 5 t (µs) Frequency (Hz) Figure 23: Input referred noise Vout (V) Figure 19: Linearity error 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 11/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Maximum continuous DC primary current 40 90 CKSR 6-NP 35 70 60 25 IP (A) IP (A) 30 20 15 50 40 30 10 20 5 0 CKSR 15-NP 80 10 0 20 40 60 80 100 0 120 0 20 40 TA (° C) 160 80 140 70 120 IP (A) IP (A) 60 50 40 120 CKSR 50-NP 100 80 60 40 CKSR 25-NP 20 10 0 100 Figure 26: IP vs TA for CKSR 15-NP 90 20 80 TA (° C) Figure 25: IP vs TA for CKSR 6-NP 30 60 0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 TA (° C) TA (° C) Figure 27: IP vs TA for CKSR 25-NP Figure 28: IP vs TA for CKSR 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 × rated power AC Derating Frequency 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 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice Page 12/19 www.lem.com CKSR series Performance parameters definition Ampere-turns and amperes Sensitivity and linearity The transducer is sensitive to the primary current linkage ΘP (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. The linearity error εL is the maximum positive or negative difference between the measured points and the linear regression line, expressed in % of IPN. ΘP = NPIP(At) Where NP is the number of primary turn (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 (At) 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 ΘP + error In which error = VOE + VOT (TA) + εG ·ΘP·G + εL(ΘP max)·ΘP max·G + TCG·(TA-25)·ΘP·G With: ΘP = NPIP ΘP max G TCG :p rimary current linkage (At) : max primary current linkage applied to the transducer : output voltage (V) : ambient operating temperature (° C) : electrical offset voltage (V) : temperature variation of VO at temperature TA (° C) : sensitivity of the transducer (V/At) : temperature coefficient of G εG εL (ΘP max) : sensitivity error : linearity error for ΘP max Vout TA VOE VOT(TA) This model is valid for primary ampere-turns ΘP between -ΘP max and +ΘP max only. 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 measured using the following primary current cycle. IOM depends on the current value IP1 (IP1> IPM). I = OM V (t ) − V (t ) 1 : 2 G out 1 out 2 th IP (DC) IP1 0A -IP1 t t1 Ip(3) I t2 Ip(t 3) Figure 30: C urrent cycle used to measure magnetic and electrical offset (transducer supplied) Definition of typical, minimum and maximum values Minimum and maximum values for specified limiting and safety conditions have to be understood as such as well as values shown in “typical” graphs. On the other hand, measured values are part of a statistical distribution that can be specified by an interval with upper and lower limits and a probability for measured values to lie within this interval. Unless otherwise stated (e.g. “100 % tested”), the LEM definition for such intervals designated with “min” and “max” is that the probability for values of samples to lie in this interval is 99.73 %. For a normal (Gaussian) distribution, this corresponds to an interval between -3 sigma and +3 sigma. If “typical” values are not obviously mean or average values, those values are defined to delimit intervals with a probability of 68.27 %, corresponding to an interval between -sigma and +sigma for a normal distribution. Typical, maximal and minimal values are determined during the initial characterization of a product. Page 13/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Performance parameters definition (continued) Overall accuracy Electrical offset The electrical offset voltage VOE can either be measured when the ferro-magnetic parts of the transducer are: The overall accuracy at 25 °C XG is the error in the - IPN .. + IPN range, relative to the rated value IPN. ●● completely demagnetized, which is difficult to realize, It includes: ●● or in a known magnetization state, like in the current cycle shown in figure 30. ●● the electrical offset VOE ●● the sensitivity error εG 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 VOT is the variation of the electrical offset from 25 °C to the considered temperature: V (T ) = V (T ) − V (25 °C) OT OE OE Note: the transducer has to be demagnetized prior to the application of the current cycle (for example with a demagnetization tunnel). ●● the linearity error εL (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. Response and reaction times The response time tr and the reaction time tra are shown in figure 32 Both depend on the primary current di/dt. They are measured at nominal ampere-turns. I 100 % 90 % U Vout Ip tr 10 % tra Figure 31: Test connection t Figure 32: Response time tr and reaction time tra Page 14/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Application information Filtering and decoupling Supply voltage VC 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). Reference Vref 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 µF. U 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. Total Primary Resistance The primary resistance is 0.72 mΩ per conductor. In the following table, examples of primary resistance according to the number of primary turns. Number of primary turns Primary resistance RP [mΩ] 1 0.18 Recommended connections in 2 8 7 6 out 2 9 3 8 4 7 5 6 out 2 9 3 8 4 7 5 6 out 2 3 4 5 0.72 in 4 9 2.88 in Page 15/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series 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) IP (A) The following graphs show how the measuring range of each transducer version depends on the external reference voltage value Vref CKSR 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 CKSR 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 16/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR 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 CKSR 25 CKSR 50 -200 0 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 17/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series PCB footprint Assembly on PCB ●● Recommended PCB hole diameter ●● Maximum PCB thickness ●● Wave soldering profile No clean process only 1.3 mm for primary pin 0.8 mm for secondary pin 2.4 mm maximum 260 °C for 10 s 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. Page 18/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com CKSR series Dimensions (in mm, general linear tolerance ± 0.25 mm) Connection U Page 19/19 22March 2013/version 9 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice www.lem.com