For the electronic measurement of current: DC, AC, pulsed..., with galvanic isolation between the primary and the secondary circuit.

Transcription

1 Current Transducer CASR series I PN = 6, 5, 25, 5 A Ref: CASR 6-NP, CASR 5-NP, CASR 25-NP, CASR 5-NP For the electronic measurement of current: DC, AC, pulsed..., with galvanic isolation between the primary and the secondary circuit. Features Closed loop (compensated) multi-range current transducer Voltage output Single supply Isolated plastic case material recognized according to UL 94-V Compact design for PCB mounting. Advantages Very low temperature coefficient of offset Very good dv/dt immunity LTSR compatible footprint Reduced height Reference pin with two modes: Ref IN and Ref OUT Extended measuring range for unipolar measurement. Applications AC variable speed and servo motor drives Static converters for DC motor drives Battery supplied applications Uninterruptible Power Supplies (UPS) Switched Mode Power Supplies (SMPS) Power supplies for welding applications Solar inverters. Standards EN 578 UL 58 IEC 6- (safety). Application Domain Industrial. Page /8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

2 Absolute maximum ratings Parameter Symbol Unit Value Supply voltage V C V 7 Primary conductor temperature C Maximum primary current I P max A 2 x I PN ESD rating, Human Body Model (HBM) kv 4 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 Comment RMS voltage for AC isolation test 5/6Hz/ min V d kv 4. Impulse withstand voltage.2/5 µs V w kv 7.5 Partial discharge extinction pc (rms) V e V Clearance distance (pri. - sec.) dci mm 7.5 Creepage distance (pri. - sec.) dcp mm 7.5 Creepage distance (pri..- sec.) dcp mm 6.2 Shortest distance through air Shortest path along device body When mounted on PCB with recommended layout Case material - - V according to UL 94 Comparative tracking index CTI V 6 Application example - - Application example V CAT III PD2 6 V CAT III PD2 Reinforced isolation, non uniform field according to EN 578, EN 6 Simple isolation, non uniform field according to EN 578, EN 6 According to UL 58: primary potential involved in Volts RMS AC or DC - V 6 For use in a pollution degree 2 environment Environmental and mechanical characteristics Parameter Symbol Unit Min Typ Max Comment Ambient operating temperature T A C Ambient storage temperature T S C Mass m g 9 Standards EN 578, IEC 695-, IEC 6-, IEC 6326-, UL 58 Page 2/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

3 Electrical data CASR 6-NP CASR series At T A = 25 C, V C = + 5 V, N P = turn, R L, internal reference, unless otherwise noted. Parameter Symbol Unit Min Typ Max Comment Primary nominal current rms I PN A 6 Primary current, measuring range I PM A -2 2 Number of primary turns N P -,2,3 Supply voltage V C V I P (ma) I Current consumption I C ma P (ma) = 73 turns Reference I P = A V REF V 95 5 Internal reference External reference voltage V REF V 4 Output voltage V OUT V Output I P = A V OUT V V REF Electrical offset voltage V OE mv % tested V OUT - V REF Electrical offset current referred to primary I OE ma -5 5 % tested Temperature coefficient of V REF TCV REF ppm/k ±5 ±5 Internal reference Temperature coefficient of V I P = A TCV OUT ppm/k ±6 ±4 ppm/k of V - 4 C.. 85 C Theoretical sensitivity Gth mv/a mv/ I PN Sensitivity error ε G % % tested Temperature coefficient of G TCG ppm/k ±4-4 C.. 85 C Linearity error ε L -.. Magnetic offset current ( x I PN ) referred to primary Output current noise (spectral density) rms Hz.. khz referred to primary Peak-peak output ripple at oscillator frequency f = 45 khz (typ.) I OM A -.. i no µa/hz ½ 2 R L - mv 4 6 R L Reaction t ra µs.3 Response 9 t r µs.3 R L di/dt = 8 A/µs R L di/dt = 8 A/µs Frequency bandwidth (± db) BW khz 2 R L Frequency bandwidth (± 3 db) BW khz 3 R L Overall accuracy X G.7 Overall T A = 85 C X G 2.2 Accuracy X.8 T A = 85 C X.4 Page 3/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

4 Electrical data CASR 5-NP CASR series At T A = 25 C, V C = + 5 V, N P = turn, R L, internal reference, unless otherwise noted. Parameter Symbol Unit Min Typ Max Comment Primary nominal current rms I PN A 5 Primary current, measuring range I PM A -5 5 Number of primary turns N P -,2,3 Supply voltage V C V I Current consumption I C ma 5 + P (ma) I 2 + P (ma) = 73 turns Reference I P = A V REF V 95 5 Internal reference External reference voltage V REF V 4 Output voltage V OUT V Output I P = A V OUT V V REF Electrical offset voltage V OE mv % tested V OUT - V REF Electrical offset current referred to primary I OE ma % tested Temperature coefficient of V REF TCV REF ppm/k ±5 ±5 Internal reference Temperature coefficient of V I P = A TCV OUT ppm/k ±2.3 ±6 ppm/k of V - 4 C.. 85 C Theoretical sensitivity Gth mv/a mv/ I PN Sensitivity error ε G % % tested Temperature coefficient of G TCG ppm/k ±4-4 C.. 85 C Linearity error ε L -.. Magnetic offset current ( x I PN ) referred to primary Output current noise (spectral density) rms Hz.. khz referred to primary Peak-peak output ripple at oscillator frequency f = 45 khz (typ.) I OM A -.. i no µa/hz ½ 2 R L - mv 5 6 R L Reaction t ra µs.3 R L di/dt = 44 A/µs Response 9 t r µs.3 R L di/dt = 44 A/µs Frequency bandwidth (± db) BW khz 2 R L Frequency bandwidth (± 3 db) BW khz 3 R L Overall accuracy X G.2 Overall T A = 85 C X G.5 Accuracy X.8 T A = 85 C X.2 Page 4/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

5 Electrical data CASR 25-NP CASR series At T A = 25 C, V C = + 5 V, N P = turn, R L, internal reference, unless otherwise noted. Parameter Symbol Unit Min Typ Max Comment Primary nominal current rms I PN A 25 Primary current, measuring range I PM A Number of primary turns N P -,2,3 Supply voltage V C V I Current consumption I C ma 5 + P (ma) I 2 + P (ma) = 73 turns Reference I P = A V REF V 95 5 Internal reference External reference voltage V REF V 4 Output voltage V OUT V Output I P = A V OUT V V REF Electrical offset voltage V OE mv % tested V OUT - V REF Electrical offset current referred to primary I OE ma % tested Temperature coefficient of V REF TCV REF ppm/k ±5 ±5 Internal reference Temperature coefficient of V I P = A TCV OUT ppm/k ±.4 ±4 ppm/k of V - 4 C.. 85 C Theoretical sensitivity Gth mv/a mv/ I PN Sensitivity error ε G % % tested Temperature coefficient of G TCG ppm/k ±4-4 C.. 85 C Linearity error ε L -.. Magnetic offset current ( x I PN ) referred to primary Output current noise (spectral density) rms Hz.. khz referred to primary Peak-peak output ripple at oscillator frequency f = 45 khz (typ.) I OM A -.. i no µa/hz ½ 2 R L - mv 4 R L Reaction t ra µs.3 R L di/dt = 68 A/µs Response 9 t r µs.3 R L di/dt = 68 A/µs Frequency bandwidth (± db) BW khz 2 R L Frequency bandwidth (± 3 db) BW khz 3 R L Overall accuracy X G Overall T A = 85 C X G.35 Accuracy X.8 T A = 85 C X.5 Page 5/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

6 Electrical data CASR 5-NP CASR series At T A = 25 C, V C = + 5 V, N P = turn, R L, internal reference, unless otherwise noted. Parameter Symbol Unit Min Typ Max Comment Primary nominal current rms I PN A 5 Primary current, measuring range I PM A -5 5 Number of primary turns N P -,2,3 Supply voltage V C V I Current consumption I C ma 5 + P (ma) I 2 + P (ma) = 966 turns Reference I P = A V REF V 95 5 Internal reference External reference voltage V REF V 4 Output voltage V OUT V Output I P = A V OUT V V REF Electrical offset voltage V OE mv % tested V OUT - V REF Electrical offset current referred to primary I OE ma % tested Temperature coefficient of V REF TCV REF ppm/k ±5 ±5 Internal reference Temperature coefficient of V I P = A TCV OUT ppm/k ±.7 ±3 ppm/k of V - 4 C.. 85 C Theoretical sensitivity Gth mv/a 625 mv/ I PN Sensitivity error ε G % % tested Temperature coefficient of G TCG ppm/k ±4-4 C.. 85 C Linearity error ε L -.. Magnetic offset current ( x I PN ) referred to primary Output current noise (spectral density) rms Hz.. khz referred to primary Peak-peak output ripple at oscillator frequency f = 45 khz (Typ.) I OM A -.. i no µa/hz ½ 2 R L - mv 5 2 R L Reaction t ra µs.3 R L di/dt = A/µs Response 9 t r µs.3 R L di/dt = A/µs Frequency bandwidth (± db) BW khz 2 R L Frequency bandwidth (± 3 db) BW khz 3 R L Overall accuracy X G.9 Overall T A = 85 C X G.2 Accuracy X.8 T A = 85 C X. Page 6/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

7 Typical performance characteristics CASR 6-NP Linearity error () I P (A) Relative Sensitivity (db) Relative Sensitivity Phase I P = 6 A Frequency (Hz) Phase ( ) Figure : Linearity error Figure 2: Frequency response I P = 6 A IP (V) I P = 6 A IP (V) Figure 3: Step response Figure 4: Step response ino (μa/hz ½ ) Primary Voltage VP (V) kv/μs VP VREF (V)..E+.E+2.E+3.E+4.E+5.E+6.E+7 Frequency (Hz) Figure 5: Input referred noise Figure 6: dv/dt Page 7/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

8 Typical performance characteristics CASR 5-NP Linearity error () I P (A) Relative Sensitivity (db) Relative Sensitivity Phase I P = 5 A Frequency (Hz) Phase ( ) Figure 7: Linearity error Figure 8: Frequency response I P = 5 A IP (V) I P = 5 A IP (V) Figure 9: Step response Figure : Step response ino (μa/hz ½ ) Primary Voltage VP (V) kv/μs VP VREF (V)..E+.E+2.E+3.E+4.E+5.E+6.E+7 Frequency (Hz) Figure : Input referred noise Figure 2: dv/dt Page 8/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

9 Typical performance characteristics CASR 25-NP Linearity error () I P (A) Figure 3: Linearity error Relative Sensitivity (db) Relative Sensitivity Phase Frequency (Hz) Figure 4: Frequency response I P = 25 A Phase ( ) I P = 25 A IP Figure 5: Step response (V) I P = 25 A IP Figure 6: Step response (V) ino (μa/hz ½ ) Primary Voltage VP (V) kv/μs VP VREF (V)..E+.E+2.E+3.E+4.E+5.E+6.E+7 Frequency (Hz) Figure 7: Input referred noise Figure 8: dv/dt Page 9/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

10 Typical performance characteristics CASR 5-NP Linearity error () I P (A) Figure 9: Linearity error Relative Sensitivity (db) Relative Sensitivity Phase Frequency (Hz) Figure 2: Frequency response I P = 5 A Phase ( ) I P = 5 A IP (V) I P = 5 A IP (V) Figure 2: Step response Figure 22: Step response ino (μa/hz ½ ) Primary Voltage VP (V) kv/μs VP VREF (V)..E+.E+2.E+3.E+4.E+5.E+6.E+7 Frequency (Hz) Figure 23: Input referred noise Figure 24: dv/dt Page /8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

11 Maximum continuous DC primary current 4 35 CASR 6-NP T A ( C) Figure 25: I P vs T A for CASR 6-NP 9 8 CASR 5-NP T A ( C) Figure 26: I P vs T A for CASR 5-NP CASR 25-NP T A ( C) CASR 5-NP T A ( C) Figure 27: I P vs T A for CASR 25-NP Figure 28: I P vs T A for CASR 5-NP The maximum continuous DC primary current plot shows the boundary of the area for which all the following conditions are true: -- I P < I PM -- Junction temperature Tj < 25 C -- Primary conductor temperature < C -- Resistor power dissipation <.5 x rated power Frequency derating AC Derating.25 max RMS AC current / max DC current k k k M Figure 29: Maximum RMS AC primary current / maximum DC primary current vs frequency Page /8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice f (Hz)

12 Performance parameters definition Ampere-turns and amperes The transducer is sensitive to the primary current linkage Q P (also called ampere-turns). Q P =N P I P (At) Where N P I P the number of primary turn (, 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 (N P = ), 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 T A is: V OUT = G Q P + error In which error = V OE + V OT (T A ) + ε G Q P G + ε L (Q Pmax ) Q Pmax G + TCG (T A -25) Q P G With: Q P = N P I P :the input ampere-turns (At) Please read above warning. Q P max :the maxi input ampere-turns that have been applied to the transducer (At) V OUT :the secondary voltage (V) T A :the ambient temperature ( C) V OE :the electrical offset voltage (V) V OT (T A ) :the temperature variation of V O at temperature T A (V) G :the sensitivity of the transducer (V/At) ε G :the sensitivity error ε L (Q Pmax ) :the linearity error for Q Pmax This model is valid for primary ampere-turns Q P between -Q Pmax and +Q Pmax only. Sensitivity and linearity To measure sensitivity and linearity, the primary current (DC) is cycled from to I P, then to -I P and back to (equally spaced I P / steps). The sensitivity G is defined as the slope of the linear regression line for a cycle between ± I PN. The linearity error ε L is the maximum positive or negative difference between the measured points and the linear regression line, expressed in. Magnetic offset The magnetic offset current I OM 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. I OM depends on the current value I P. I P A -I P I P (DC) I OM V = t ) V 2 ( ( t ) OUT OUT 2 t Gth Figure 3: Current cycle used to measure magnetic and electrical offset (transducer supplied) t 2 t Page 2/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

13 Performance parameters definition (continued) Electrical offset The electrical offset voltage V OE can either be measured when the ferro-magnetic parts of the transducer are: completely demagnetized, which is difficult to realize, or in a known magnetization state, like in the current cycle shown in figure 3. Using the current cycle shown in figure 3, the electrical offset is: V ( t ) + V ( t ) OUT OUT 2 V = OE 2 The temperature variation V OT of the electrical offset voltage V OE 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). Overall accuracy The overall accuracy at 25 C X G is the error in the - I PN.. + I PN range, relative to the rated value I PN. It includes: the electrical offset V OE the sensitivity error e G the linearity error e L (to I PN ) 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 I PN. Response and reaction times The response time t r and the reaction time t ra are shown in figure 3. Both depend on the primary current di/dt. They are measured at nominal ampere-turns. I 9 8 % 9 % Ip t r % 2 3 t ra t Figure 3: Test connection Figure 32: Response time t r and reaction time t ra Page 3/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

14 Application information Filtering and decoupling Supply voltage V C The fluxgate oscillator draws current pulses of up to 3 ma at a rate of ca. 9 khz. Significant 9 khz voltage ripple on V C 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 V OUT and reference V REF. The transducer has internal decoupling capacitors, but in the case of a power supply with high impedance, it is advised to provide local decoupling ( nf or more, located close to the transducer) Reference V REF Ripple present on the reference output can be filtered with a low value of capacitance because of the internal 68 Ohm series resistance. The maximum filter capacitance value is µf.application information 9 8 Output V OUT The output V OUT has a very low output impedance of typically 2 Ohms; it can drive pf directly. Adding series Rf = Ohms allows much larger capacitive loads. Empirical evaluation may be necessary to obtain optimum results. The minimum load resistance on V OUT is kohm. 2 3 Total Primary Resistance The primary resistance is.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 R P [mw] Recommended connections 9 8 OUT IN OUT IN OUT IN 2 3 Page 4/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

15 External reference voltage Application information (continued) If the Ref pin of the transducer is not used it could be either left unconnected or filtered according to the previous paragraph Reference V REF. The Ref pin has two modes Ref IN and Ref OUT: In the Ref OUT mode the 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 68 Ohms resistor. it tolerates sink or source currents up to ± 5 ma, but the 68 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 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 Vref, the maximum value will be 2.2 ma typ. when Vref = 4 V or to sink a typical current of Vref 68, the maximum value will be 3.68 ma typ. when Vref = V. The following graphs show how the measuring range of each transducer version depends on the external reference voltage value Vref. I P (A) CASR V REF (V) I P (A) CASR V REF (V) Upper limit : I P = -9.6 * Vref (Vref =.. 4 V) Upper limit : I P = -24 * Vref + (Vref = V) Upper limit : I P = 8 (Vref =...29 V) Lower limit : I P = -9.6 * Vref (Vref =.. 4 V) Lower limit : I P = -24 * Vref + 9 (Vref = V) Lower limit : I P = -8 (Vref = V) Page 5/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

16 External reference voltage (continued) I P (A) CASR V REF (V) I P (A) CASR V REF (V) Upper limit : I P = -4 * Vref + 85 (Vref =.. 4 V) Upper limit : I P = -8 * Vref + 37 (Vref = V) Upper limit : I P = 85 (Vref =.. V) Upper limit : I P = 5 (Vref = V) Lower limit : I P = -4 * Vref + 5 (Vref =.. V) Lower limit : I P = -8 * Vref + 3 (Vref = V) Lower limit : I P = -85 (Vref =.. 4 V) Lower limit : I P = -5 (Vref = V) Example with V REF =.65 V: The 6 A version has a measuring range from A to A The 5 A version has a measuring range from A to A The 25 A version has a measuring range from - 5 A to + 85 A The 5 A version has a measuring range from - 2 A to + 5 A Example with V REF = V: The 6 A version has a measuring range from A to A The 5 A version has a measuring range from + 9 A to + 8 A The 25 A version has a measuring range from + 5 A to + 85 A The 5 A version has a measuring range from + 3 A to + 5 A Page 6/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

17 CASR Series, PCB footprint Assembly on PCB Recommended PCB hole diameter.3 mm for primary pin.8 mm for secondary pin Maximum PCB thickness mm Wave soldering profile maximum 26 C for s No clean process only. Safety This transducer must be used in limited-energy secondary circuits according to IEC 6-. 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 7/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

18 Dimensions CASR Series (in mm. General linear tolerance ±.25 mm) Connection Page 8/8 8March22/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice