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CASR 15-NP
Current Transducer, CASR Series, 15A, -51A to 51A, 0.8 %, Voltage Output, 4.75 Vdc to 5.25 Vdc
⚠️ Reference pricing provided. In case of supply shortages, we will connect you with our trusted procurement partners to ensure your project's continuity.
- Manufacturer: LEM
- Product type: Current Sensors
- Sensor Output:Voltage; Supply Voltage DC Min:4.75V; Supply Voltage DC Max:5.25V; Current Measuring Range DC:-51A to 51A; Current Measuring Range AC:-51A to 51A; Response Time:0.3µs; Accuracy
- SVHC: No SVHC (25-Jun-2025)
- Accuracy: ± 0.8%
- Accuracy %: 0.8%
- Product Range: CASR Series
- Primary Current: 15A
- Sensor Mounting: Through Hole
- Measured Current: AC / DC / Pulsed
- Sensor Output Type: Voltage
- Supply Voltage Range: 4.75V to 5.25V
- Secondary Signal Type: 2.5V
- Supply Voltage DC Max: 5.25V
- Supply Voltage DC Min: 4.75V
- Current Sensor Technology: Closed Loop, Flux Gate
- Operating Temperature Max: 85°C
- Operating Temperature Min: -40°C
- Current Measuring Range AC: -51A to 51A
- Current Measuring Range DC: -51A to 51A
| Delivery and price | |
|---|---|
| Units per pack | 50 |
| Price | 12.23 € |
| Current stock | 50+ |
| Lead time | 30 days |
Datasheet
## **Current Transducer CASR series** ## **I = 6, 15, 25, 50 A** PN ## **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 current transducer - ●Voltage output - ●Single supply - ●Isolated plastic case material recognized according to UL 94-V0 - ●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. - ●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 50178 - ●UL 508 - ●IEC 61010-1 (safety). ## **Application Domain** - ●Industrial. Page 1/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **Absolute maximum ratings** **==> picture [511 x 21] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Value<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Value**| |---|---|---|---| ||||| |Supply voltage|**V**C|V|7| |Primary conductor temperature||°C|110| |Maximum primary current|**I**P max|A|20 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** **==> picture [512 x 55] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Value Comment<br>RMS voltage for AC isolation test 50/60Hz/1 min V d kV 4.1<br>Impulse withstand voltage 1.2/50 µs V w kV 7.5<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Value**|**Comment**| |---|---|---|---|---| |RMS voltage for AC isolation test 50/60Hz/1 min|**V**d|kV|4.1|| |Impulse withstand voltage 1.2/50 µs|**V**w|kV|7.5|| |||||| |Partial discharge extinction voltage @ 10 pC (rms)|**V**e|V|1000|| |Clearance distance (pri. - sec.)|**dCI**|mm|7.5|Shortest distance through<br>air| |Creepage distance (pri. - sec.)|**dCp**|mm|7.5|Shortest path along device<br>body| |Creepage distance (pri. .- sec.)|**dCp**|mm|6.2|When mounted on PCB<br>with recommended layout| |Case material|-|-|V0 according<br>to UL 94|| |Comparative tracking index|**CTI**|V|600|| |Application example|-|-|300 V CAT III<br>PD2|Reinforced isolation, non<br>uniform feld according to<br>EN 50178, EN 61010| |Application example|-|-|600 V CAT III<br>PD2|Simple isolation, non<br>uniform feld according to<br>EN 50178, EN 61010| |According to UL 508:<br>primary potential involved in Volts RMS AC or DC|-|V|600|For use in a pollution<br>degree 2 environment| ## **Environmental and mechanical characteristics** |**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Max**|**Comment**| |---|---|---|---|---|---|---| |Ambient operating temperature|**T**A|°C|-40||85|| |Ambient storage temperature|**T**S|°C|-55||105|| |Mass|**_m_**|g||9||| |Standards|EN 50178, IEC 60950-1, IEC 61010-1, IEC 61326-1, UL 508|||||| Page 2/18 www.lem.com LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 **CASR series** ## **Electrical data CASR 6-NP** At **T** A = 25°C, **V** C = + 5 V, **N** P = 1 turn, **R** L = 10 kΩ, internal reference, unless otherwise noted. **==> picture [513 x 21] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Typ**|**Max**|**Max**|**Comment**| |---|---|---|---|---|---|---|---|---| |||||||||| |Primary nominal current rms|**I**PN|A||6||||| |Primary current, measuring range|**I**PM|A|-20|||20||| |Number of primary turns|**N**P|-||1,2,3||||| |Supply voltage|**V**C|V|4.75||5|5.25||| |Current consumption|**I**C|mA||15 +|<br>**I**P(mA)<br> **N**S|20 +|**I**P(mA)<br> **N**S|**N**S= 1731 turns| |Reference voltage @**I**P= 0 A|**V**REF|V|2.495||2.5|2.505||Internal reference| |External reference voltage|**V**REF|V|0|||4||| |Output voltage|**V**OUT|V|0.375|||4.625||| |Output voltage @**I**P= 0 A|**V**OUT|V||**V**REF||||| |Electrical offset voltage|**V**OE|mV|-5.3|||5.3||100% tested<br>**V**OUT-**V**REF| |Electrical offset current referred to<br>primary|**I**OE|mA|-51|||51||100% tested| |Temperature coeffcient of**V**REF|**TCV**REF|ppm/K||±5||±50||Internal reference| |Temperature coeffcient of**V**OUT<br>@**I**P= 0 A|**TCV**OUT|ppm/K||±6||±14||ppm/K of 2.5 V<br>- 40°C .. 85°C| |Theoretical sensitivity|**Gth**|mV/A||104.2||||625 mV/**I**PN| |Sensitivity error|εG|%|-0.7|||0.7||100% tested| |Temperature coeffcient of**G**|**TCG**|ppm/K||||±40||- 40°C .. 85°C| |Linearity error|εL|% of**I**PN|-0.1|||0.1||| |Magnetic offset current (10 x**I**PN)<br>referred to primary|**I**OM|A|-0.1|||0.1||| |Output current noise (spectral<br>density) rms 100 Hz .. 100 kHz<br>referred to primary|ino|µA/Hz½||20||||RL= 1 kΩ| |Peak-peak output ripple at oscillator<br>frequency**f**= 450 kHz (typ.)|**-**|mV||40||160||RL= 1 kΩ| |Reaction time @ 10 % of**I**PN|**t**ra|µs||||0.3||RL= 1 kΩ<br>di/dt = 18 A/µs| |Response time @ 90 % of**I**PN|**t**r|µs||||0.3||RL= 1 kΩ<br>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|**X**G|% of**I**PN||||1.7||| |Overall accuracy @**T**A= 85°C|**X**G|% of**I**PN||||2.2||| |Accuracy|**X**|% of**I**PN||||0.8||| |Accuracy @**T**A= 85°C|**X**|% of**I**PN||||1.4||| Page 3/18 www.lem.com 8March2012/version 7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice **CASR series** ## **Electrical data CASR 15-NP** At **T** A = 25°C, **V** C = + 5 V, **N** P = 1 turn, **R** L = 10 kΩ, internal reference, unless otherwise noted. **==> picture [513 x 21] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Typ**|**Max**|**Comment**| |---|---|---|---|---|---|---|---| ||||||||| |Primary nominal current rms|**I**PN|A||15|||| |Primary current, measuring range|**I**PM|A|-51|||51|| |Number of primary turns|**N**P|-||1,2,3|||| |Supply voltage|**V**C|V|4.75||5|5.25|| |Current consumption|**I**C|mA||15 +|<br>**I**P(mA)<br> **N**S|20 +<br>**I**P(mA)<br> **N**S|**N**S= 1731 turns| |Reference voltage @**I**P= 0 A|**V**REF|V|2.495||2.5|2.505|Internal reference| |External reference voltage|**V**REF|V|0|||4|| |Output voltage|**V**OUT|V|0.375|||4.625|| |Output voltage @**I**P= 0 A|**V**OUT|V||**V**REF|||| |Electrical offset voltage|**V**OE|mV|-2.21|||2.21|100% tested<br>**V**OUT-**V**REF| |Electrical offset current referred to<br>primary|**I**OE|mA|-53|||53|100% tested| |Temperature coeffcient of**V**REF|**TCV**REF|ppm/K||±5||±50|Internal reference| |Temperature coeffcient of**V**OUT<br>@**I**P= 0 A|**TCV**OUT|ppm/K||±2.3||±6|ppm/K of 2.5 V<br>- 40°C .. 85°C| |Theoretical sensitivity|**Gth**|mV/A||41.67|||625 mV/**I**PN| |Sensitivity error|εG|%|-0.7|||0.7|100% tested| |Temperature coeffcient of**G**|**TCG**|ppm/K||||±40|- 40°C .. 85°C| |Linearity error|εL|% of**I**PN|-0.1|||0.1|| |Magnetic offset current (10 x**I**PN)<br>referred to primary|**I**OM|A|-0.1|||0.1|| |Output current noise (spectral<br>density) rms 100 Hz .. 100 kHz<br>referred to primary|ino|µA/Hz½||20|||**R**L= 1 kΩ| |Peak-peak output ripple at oscillator<br>frequency**f**= 450 kHz (typ.)|**-**|mV||15||60|**R**L= 1 kΩ| |Reaction time @ 10 % of**I**PN|**t**ra|µs||||0.3|**R**L= 1 kΩ<br>di/dt = 44 A/µs| |Response time @ 90 % of**I**PN|**t**r|µs||||0.3|**R**L= 1 kΩ<br>di/dt = 44 A/µs| |Frequency bandwidth (± 1 dB)|**BW**|kHz|200||||**R**L= 1 kΩ| |Frequency bandwidth (± 3 dB)|**BW**|kHz|300||||**R**L= 1 kΩ| |Overall accuracy|**X**G|% of**I**PN||||1.2|| |Overall accuracy @**T**A= 85°C|**X**G|% of**I**PN||||1.5|| |Accuracy|**X**|% of**I**PN||||0.8|| |Accuracy @**T**A= 85°C|**X**|% of**I**PN||||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 **T** A = 25°C, **V** C = + 5 V, **N** P = 1 turn, **R** L = 10 kΩ, internal reference, unless otherwise noted. **==> picture [513 x 21] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Typ**|**Max**|**Max**|**Comment**| |---|---|---|---|---|---|---|---|---| |||||||||| |Primary nominal current rms|**I**PN|A||25||||| |Primary current, measuring range|**I**PM|A|-85|||85||| |Number of primary turns|**N**P|-||1,2,3||||| |Supply voltage|**V**C|V|4.75||5|5.25||| |Current consumption|**I**C|mA||15 +|<br>**I**P(mA)<br> **N**S|20 +|**I**P(mA)<br> **N**S|**N**S= 1731 turns| |Reference voltage @**I**P= 0 A|**V**REF|V|2.495||2.5|2.505||Internal reference| |External reference voltage|**V**REF|V|0|||4||| |Output voltage|**V**OUT|V|0.375|||4.625||| |Output voltage @**I**P= 0 A|**V**OUT|V||**V**REF||||| |Electrical offset voltage|**V**OE|mV|-1.35|||1.35||100% tested<br>**V**OUT-**V**REF| |Electrical offset current referred to<br>primary|**I**OE|mA|-54|||54||100% tested| |Temperature coeffcient of**V**REF|**TCV**REF|ppm/K||±5||±50||Internal reference| |Temperature coeffcient of**V**OUT<br>@**I**P= 0 A|**TCV**OUT|ppm/K||±1.4||±4||ppm/K of 2.5 V<br>- 40°C .. 85°C| |Theoretical sensitivity|**Gth**|mV/A||25||||625 mV/**I**PN| |Sensitivity error|εG|%|-0.7|||0.7||100% tested| |Temperature coeffcient of**G**|**TCG**|ppm/K||||±40||- 40°C .. 85°C| |Linearity error|εL|% of**I**PN|-0.1|||0.1||| |Magnetic offset current (10 x**I**PN)<br>referred to primary|**I**OM|A|-0.1|||0.1||| |Output current noise (spectral<br>density) rms 100 Hz .. 100 kHz<br>referred to primary|ino|µA/Hz½||20||||**R**L= 1 kΩ| |Peak-peak output ripple at oscillator<br>frequency**f**= 450 kHz (typ.)|**-**|mV||10||40||**R**L= 1 kΩ| |Reaction time @ 10 % of**I**PN|**t**ra|µs||||0.3||**R**L= 1 kΩ<br>di/dt = 68 A/µs| |Response time @ 90 % of**I**PN|**t**r|µs||||0.3||**R**L= 1 kΩ<br>di/dt = 68 A/µs| |Frequency bandwidth (± 1 dB)|**BW**|kHz|200|||||**R**L= 1 kΩ| |Frequency bandwidth (± 3 dB)|**BW**|kHz|300|||||**R**L= 1 kΩ| |Overall accuracy|**X**G|% of**I**PN||||1||| |Overall accuracy @**T**A= 85°C|**X**G|% of**I**PN||||1.35||| |Accuracy|**X**|% of**I**PN||||0.8||| |Accuracy @**T**A= 85°C|**X**|% of**I**PN||||1.15||| 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 **T** A = 25°C, **V** C = + 5 V, **N** P = 1 turn, **R** L = 10 kΩ, internal reference, unless otherwise noted. **==> picture [512 x 21] intentionally omitted <==** **----- Start of picture text -----**<br> Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br> |**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Typ**|**Max**|**Max**|**Comment**| |---|---|---|---|---|---|---|---|---| |||||||||| |Primary nominal current rms|**I**PN|A||50||||| |Primary current, measuring range|**I**PM|A|-150|||150||| |Number of primary turns|**N**P|-||1,2,3||||| |Supply voltage|**V**C|V|4.75||5|5.25||| |Current consumption|**I**C|mA||15 +|<br>**I**P(mA)<br> **N**S|20 +|**I**P(mA)<br> **N**S|**N**S= 966 turns| |Reference voltage @**I**P= 0 A|**V**REF|V|2.495||2.5|2.505||Internal reference| |External reference voltage|**V**REF|V|0|||4||| |Output voltage|**V**OUT|V|0.375|||4.625||| |Output voltage @**I**P= 0 A|**V**OUT|V||**V**REF||||| |Electrical offset voltage|**V**OE|mV|-0.725|||0.725||100% tested<br>**V**OUT-**V**REF| |Electrical offset current referred to<br>primary|**I**OE|mA|-58|||58||100% tested| |Temperature coeffcient of**V**REF|**TCV**REF|ppm/K||±5||±50||Internal reference| |Temperature coeffcient of**V**OUT<br>@**I**P= 0 A|**TCV**OUT|ppm/K||±0.7||±3||ppm/K of 2.5 V<br>- 40°C .. 85°C| |Theoretical sensitivity|**Gth**|mV/A||12.5||||625 mV/**I**PN| |Sensitivity error|εG|%|-0.7|||0.7||100% tested| |Temperature coeffcient of**G**|**TCG**|ppm/K||||±40||- 40°C .. 85°C| |Linearity error|εL|% of**I**PN|-0.1|||0.1||| |Magnetic offset current (10 x**I**PN)<br>referred to primary|**I**OM|A|-0.1|||0.1||| |Output current noise (spectral density)<br>rms 100 Hz .. 100 kHz referred to<br>primary|ino|µA/Hz½||20||||RL= 1 kΩ| |Peak-peak output ripple at oscillator<br>frequency**f**= 450 kHz (Typ.)|**-**|mV||5||20||RL= 1 kΩ| |Reaction time @ 10 % of**I**PN|**t**ra|µs||||0.3||**R**L= 1 kΩ<br>di/dt = 100 A/µs| |Response time @ 90 % of**I**PN|**t**r|µs||||0.3||**R**L= 1 kΩ<br>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|**X**G|% of**I**PN||||0.9||| |Overall accuracy @**T**A= 85°C|**X**G|% of**I**PN||||1.2||| |Accuracy|**X**|% of**I**PN||||0.8||| |Accuracy @**T**A= 85°C|**X**|% of**I**PN||||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** ## **Typical performance characteristics CASR 6-NP** **==> picture [197 x 146] intentionally omitted <==** **----- Start of picture text -----**<br> 0.1<br>0.05<br>0<br>-0.05<br>-0.1<br>-6 0 6<br>IP (A)<br>)<br>PN<br>Linearity error (% of I<br>**----- End of picture text -----**<br> **==> picture [220 x 156] intentionally omitted <==** **----- Start of picture text -----**<br> 1 1<br>0.8 IP = 6 A 0<br>0.6 -1<br>0.4 -2<br>0.2 -3<br>0 -4<br>-0.2 -5<br>-0.4 -6<br>-0.6 Relative -7<br>-0.8 Sensitivity -8<br>Phase<br>-1 -9<br>100 1000 10000 100000 1000000<br>Frequency (Hz)<br>Phase (°)<br>Relative Sensitivity (dB)<br>**----- End of picture text -----**<br> _Figure 1: Linearity error_ _Figure 2: Frequency response_ **==> picture [480 x 363] intentionally omitted <==** **----- Start of picture text -----**<br> 7 3.2 7 3.2<br>6 3.1 6 3.1<br>5 3.0 5 3.0<br>4 2.9 4 2.9<br>IP = 6 A IP = 6 A<br>3 2.8 3 2.8<br>2 IP 2.7 2 IP 2.7<br>1 VOUT 2.6 1 VOUT 2.6<br>0 2.5 0 2.5<br>-1 2.4 -1 2.4<br>-0.5 0 0.5 1 1.5 2 -2 0 2 4 6 8 10<br>t (µs) t (µs)<br>Figure 3: Step response Figure 4: Step response<br>10000 800 3.6<br>600<br>3.4<br>1000<br>400<br>3.2<br>100 200<br>0 20 kV/μs 3.0<br>10<br>-200 VP 2.8<br>VOUT<br>1 -400 VREF<br>2.6<br>-600<br>0.1 -800 2.4<br>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<br>Frequency (Hz) t (µs)<br> (A) IP (V)OUT (A) IP (V)OUT<br>V V<br> (V)<br>P<br>)<br>½<br> (V)<br> (μA/Hz OUT<br>ino V<br>Primary Voltage V<br>**----- End of picture text -----**<br> _Figure 5: Input referred noise_ _Figure 6: dv/dt_ Page 7/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **Typical performance characteristics CASR 15-NP** **==> picture [199 x 152] intentionally omitted <==** **----- Start of picture text -----**<br> 0.1<br>0.05<br>0<br>-0.05<br>-0.1<br>-15 0 15<br>IP (A)<br>)<br>PN<br>Linearity error (% of I<br>**----- End of picture text -----**<br> _Figure 7: Linearity error_ **==> picture [221 x 156] intentionally omitted <==** **----- Start of picture text -----**<br> 1 1<br>0.8 IP = 15 A 0<br>0.6 -1<br>0.4 -2<br>0.2 -3<br>0 -4<br>-0.2 -5<br>-0.4 -6<br>-0.6 Relative -7<br>-0.8 Sensitivity -8<br>Phase<br>-1 -9<br>100 1000 10000 100000 1000000<br>Frequency (Hz)<br>Phase (°)<br>Relative Sensitivity (dB)<br>**----- End of picture text -----**<br> _Figure 8: Frequency response_ **==> picture [227 x 160] intentionally omitted <==** **----- Start of picture text -----**<br> 17.5 3.2<br>15 3.1<br>12.5 3.0<br>10 2.9<br>IP = 15 A<br>7.5 2.8<br>5 IP 2.7<br>2.5 VOUT 2.6<br>0 2.5<br>-2.5 2.4<br>-0.5 0 0.5 1 1.5 2<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 9: Step response_ **==> picture [228 x 160] intentionally omitted <==** **----- Start of picture text -----**<br> 17.5 3.2<br>15 3.1<br>12.5 3.0<br>10 2.9<br>IP = 15 A<br>7.5 2.8<br>5 IP 2.7<br>2.5 VOUT 2.6<br>0 2.5<br>-2.5 2.4<br>-2 0 2 4 6 8 10<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 10: Step response_ **==> picture [480 x 158] intentionally omitted <==** **----- Start of picture text -----**<br> 10000 800 3.6<br>600<br>3.4<br>1000<br>400<br>3.2<br>200<br>100<br>0 20 kV/μs 3.0<br>10 -200 VP 2.8<br>VOUT<br>1 -400 VREF<br>2.6<br>-600<br>0.1 -800 2.4<br>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<br>Frequency (Hz) t (µs)<br> (V)<br>P<br>)<br>½<br> (V)<br> (μA/Hz VOUT<br>ino<br>Primary Voltage V<br>**----- End of picture text -----**<br> _Figure 11: Input referred noise_ _Figure 12: dv/dt_ Page 8/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **Typical performance characteristics CASR 25-NP** **==> picture [198 x 158] intentionally omitted <==** **----- Start of picture text -----**<br> 0.1<br>0.05<br>0<br>-0.05<br>-0.1<br>-25 0 25<br>IP (A)<br>)<br>PN<br>Linearity error (% of I<br>**----- End of picture text -----**<br> _Figure 13: Linearity error_ **==> picture [221 x 156] intentionally omitted <==** **----- Start of picture text -----**<br> 1 1<br>0.8 IP = 25 A 0<br>0.6 -1<br>0.4 -2<br>0.2 -3<br>0 -4<br>-0.2 -5<br>-0.4 -6<br>-0.6 Relative -7<br>-0.8 Sensitivity -8<br>Phase<br>-1 -9<br>100 1000 10000 100000 1000000<br>Frequency (Hz)<br>Phase (°)<br>Relative Sensitivity (dB)<br>**----- End of picture text -----**<br> _Figure 14: Frequency response_ **==> picture [221 x 163] intentionally omitted <==** **----- Start of picture text -----**<br> 29.2 3.2<br>25.0 3.1<br>20.8 3.0<br>16.7 2.9<br>IP = 25 A<br>12.5 2.8<br>8.3 IP 2.7<br>4.2 VOUT 2.6<br>0.0 2.5<br>-4.2 2.4<br>-0.5 0 0.5 1 1.5 2<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 15: Step response_ **==> picture [223 x 164] intentionally omitted <==** **----- Start of picture text -----**<br> 29.2 3.2<br>25.0 3.1<br>20.8 3.0<br>16.7 2.9<br>IP = 25 A<br>12.5 2.8<br>8.3 IP 2.7<br>4.2 VOUT 2.6<br>0.0 2.5<br>-4.2 2.4<br>-2 0 2 4 6 8 10<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 16: Step response_ **==> picture [202 x 156] intentionally omitted <==** **----- Start of picture text -----**<br> 10000<br>1000<br>100<br>10<br>1<br>0.1<br>1.E+1 1.E+2 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7<br>Frequency (Hz)<br>)<br>½<br> (μA/Hz<br>ino<br>**----- End of picture text -----**<br> _Figure 17: Input referred noise_ **==> picture [228 x 157] intentionally omitted <==** **----- Start of picture text -----**<br> 800 3.6<br>600<br>3.4<br>400<br>3.2<br>200<br>0 20 kV/μs 3.0<br>-200 VP 2.8<br>VOUT<br>-400 VREF<br>2.6<br>-600<br>-800 2.4<br>-1 0 1 2 3 4 5<br>t (µs)<br> (V)<br>P<br> (V)<br>OUT<br>V<br>Primary Voltage V<br>**----- End of picture text -----**<br> _Figure 18: dv/dt_ Page 9/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **Typical performance characteristics CASR 50-NP** **==> picture [202 x 157] intentionally omitted <==** **----- Start of picture text -----**<br> 0.1<br>0.05<br>0<br>-0.05<br>-0.1<br>-50 0 50<br>IP (A)<br>)<br>PN<br>Linearity error (% of I<br>**----- End of picture text -----**<br> _Figure 19: Linearity error_ **==> picture [221 x 157] intentionally omitted <==** **----- Start of picture text -----**<br> 1 1<br>0.8 IP = 50 A 0<br>0.6 -1<br>0.4 -2<br>0.2 -3<br>0 -4<br>-0.2 -5<br>-0.4 -6<br>-0.6 Relative -7<br>-0.8 Sensitivity -8<br>Phase<br>-1 -9<br>100 1000 10000 100000 1000000<br>Frequency (Hz)<br>Phase (°)<br>Relative Sensitivity (dB)<br>**----- End of picture text -----**<br> _Figure 20: Frequency response_ **==> picture [226 x 163] intentionally omitted <==** **----- Start of picture text -----**<br> 58.3 3.2<br>50.0 3.1<br>41.7 3.0<br>33.3 2.9<br>IP = 50 A<br>25.0 2.8<br>16.7 IP 2.7<br>8.3 VOUT 2.6<br>0.0 2.5<br>-8.3 2.4<br>-0.5 0 0.5 1 1.5 2<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 21: Step response_ **==> picture [220 x 164] intentionally omitted <==** **----- Start of picture text -----**<br> 58.3 3.2<br>50.0 3.1<br>41.7 3.0<br>33.3 2.9<br>IP = 50 A<br>25.0 2.8<br>16.7 IP 2.7<br>8.3 VOUT 2.6<br>0.0 2.5<br>-8.3 2.4<br>-2 0 2 4 6 8 10<br>t (µs)<br> (A) (V)<br>IP OUT<br>V<br>**----- End of picture text -----**<br> _Figure 22: Step response_ **==> picture [479 x 157] intentionally omitted <==** **----- Start of picture text -----**<br> 10000 800 3.6<br>600<br>3.4<br>1000<br>400<br>3.2<br>200<br>100<br>0 20 kV/μs 3.0<br>10 -200 VP 2.8<br>VOUT<br>-400 VREF<br>1<br>2.6<br>-600<br>0.1 -800 2.4<br>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<br>Frequency (Hz) t (µs)<br> (V)<br>P<br>)<br>½<br> (V)<br>OUT<br> (μA/Hz V<br>ino<br>Primary Voltage V<br>**----- End of picture text -----**<br> _Figure 23: Input referred noise_ _Figure 24: dv/dt_ Page 10/18 www.lem.com LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 **CASR series** ## **Maximum continuous DC primary current** **==> picture [198 x 342] intentionally omitted <==** **----- Start of picture text -----**<br> 40<br>35 CASR 6-NP<br>30<br>25<br>20<br>15<br>10<br>5<br>0<br>0 20 40 60 80 100 120<br>TA (°C)<br>Figure 25: I P vs T A for CASR 6-NP<br>90<br>80<br>70<br>60 CASR 25-NP<br>50<br>40<br>30<br>20<br>10<br>0<br>0 20 40 60 80 100 120<br>TA (°C)<br> (A)<br>P<br> I<br> (A)<br>P<br> I<br>**----- End of picture text -----**<br> _Figure 27:_ _**I** P vs_ _**T** A for CASR 25-NP_ **==> picture [199 x 344] intentionally omitted <==** **----- Start of picture text -----**<br> 90<br>80<br>CASR 15-NP<br>70<br>60<br>50<br>40<br>30<br>20<br>10<br>0<br>0 20 40 60 80 100 120<br>TA (°C)<br>Figure 26: I P vs T A for CASR 15-NP<br>160<br>140 CASR 50-NP<br>120<br>100<br>80<br>60<br>40<br>20<br>0<br>0 20 40 60 80 100 120<br>TA (°C)<br> (A)<br>P<br> I<br> (A)<br>P<br> I<br>**----- End of picture text -----**<br> _Figure 28:_ _**I** P vs_ _**T** A 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: - **I** < **I** P PM - Junction temperature Tj < 125 °C - Primary conductor temperature < 110 °C - Resistor power dissipation < 0.5 x rated power ## **Frequency derating** ## **AC Derating** **==> picture [213 x 161] intentionally omitted <==** **----- Start of picture text -----**<br> 1.25<br>1<br>0.75<br>0.5<br>0.25<br>0<br>10 100 1k 10k 100k 1M<br>f (Hz)<br>max DC current<br>max RMS AC current /<br>**----- End of picture text -----**<br> _Figure 29: Maximum RMS AC primary current / maximum DC primary current vs frequency_ Page 11/18 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** ## **Ampere-turns and amperes** The transducer is sensitive to the primary current linkage QP (also called ampere-turns). QP= **N** P **I** P(At) Where **N** P **I** P 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 ( **N** P = 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 **T** A is: **V** = G Q + error OUT P In which error = **V** OE + **V** OT ( **T** A) + εG ·QP·G + εL(QPmax)·QPmax·G + **TCG** ·( **T** A-25)·QP· **G** With: QP = **N** P **I** P :the input ampere-turns (At) Please read above warning. QPmax :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) εG :the sensitivity error εL (QPmax) :the linearity error for QPmax This model is valid for primary ampere-turns QP between -QPmax and +QPmax only. ## **Sensitivity and linearity** To measure sensitivity and linearity, the primary current (DC) is cycled from 0 to **I** P, then to - **I** P and back to 0 (equally spaced **I** P/10 steps). The sensitivity G is defined as the slope of the linear regression line for a cycle between ± **I** PN. The linearity error εL is the maximum positive or negative difference between the measured points and the linear regression line, expressed in % of **I** PN. ## **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** P1. **==> picture [197 x 159] intentionally omitted <==** **----- Start of picture text -----**<br> I OM = VOUT ( t 1) − 2 VOUT ( t 2 ) ⋅ Gth 1<br>IP (DC)<br>IP1<br>t2<br>0 A<br> t1 t<br>-IP1<br>**----- End of picture text -----**<br> _Figure 30: Current cycle used to measure magnetic and electrical offset (transducer supplied)_ Page 12/18 www.lem.com LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 **CASR series** ## **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 30. **==> picture [250 x 40] intentionally omitted <==** The temperature variation **V** OT of the electrical offset voltage **V** is the variation of the electrical offset from 25°C to the OE considered temperature: **==> picture [105 x 10] intentionally omitted <==** Note: the transducer has to be demagnetized prior to the application of the current cycle (for example with a demagnetization tunnel). **==> picture [186 x 99] intentionally omitted <==** **----- Start of picture text -----**<br> 10 9 8<br>1 2 3<br>**----- End of picture text -----**<br> ## **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 εG - ●the linearity error εL (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 tfigure 31. r and the reaction time tra are shown in Both depend on the primary current di/dt. They are measured at nominal ampere-turns. **==> picture [210 x 113] intentionally omitted <==** **----- Start of picture text -----**<br> I<br>100 %<br>90 %<br>VOUT<br>Ip<br>tr<br>10 %<br>t r a t<br>**----- End of picture text -----**<br> _Figure 31: Test connection_ _Figure 32: Response time tr and reaction time tra_ Page 13/18 www.lem.com LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 **CASR series** ## **Application information** ## **Filtering and decoupling** ## **Supply voltage V** C The fluxgate oscillator draws current pulses of up to 30 mA at a rate of ca. 900 kHz. Significant 900 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 (100 nF or more, located close to the transducer) ## **Output V** OUT The output **V** OUT 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 **V** is 1 kOhm. OUT ## **Reference V** REF 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.Application information **==> picture [237 x 100] intentionally omitted <==** **----- Start of picture text -----**<br> 10 9 8<br>1 2 3<br>**----- End of picture text -----**<br> ## **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<br>primary turns|Primary<br>resistance<br>**R**P[mW]|R<br>|ecommended<br>connections| |---|---|---|---| |1|0.24|1<br>IN 1|0 9 8 OUT<br>23| |2|1.08|1<br>IN 1|0 9 8 OUT<br>2 3| |3|2.16|1<br>IN 1|0 9 8 OUT<br>2 3| Page 14/18 www.lem.com LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 **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 **V** ”. REF 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: _Vref_ − 5.2 - either to source a typical current of , the maximum value will be 2.2 mA typ. when Vref = 4 V. 680 - or to sink a typical current of **==> picture [284 x 26] intentionally omitted <==** **----- Start of picture text -----**<br> 5.2 − Vref<br>, the maximum value will be 3.68 mA typ. when Vref = 0 V.<br>680<br>**----- End of picture text -----**<br> The following graphs show how the measuring range of each transducer version depends on the external reference voltage value Vref. **==> picture [473 x 169] intentionally omitted <==** **----- Start of picture text -----**<br> 50 100<br>40 80<br>30 60<br>20 40<br>10 20<br>0 0<br>-10 -20<br>-20 -40<br>-30 -60<br>-40 CASR 6 -80 CASR 15<br>-50 -100<br>0 1 2 3 4<br>0 1 2 3 4<br>VREF (V)<br>VREF (V)<br> (A) (A)<br>P<br> I I P<br>**----- End of picture text -----**<br> Upper limit : IP = -9.6 * Vref + 44.4 (Vref = 0 .. 4 V) Lower limit : IP = -9.6 * Vref + 3.6 (Vref = 0 .. 4 V) Upper limit : IP = -24 * Vref + 111 (Vref = 1.29 .. 4 V) Upper limit : IP = 80 (Vref = 0 .. 1.29 V) Lower limit : IP = -24 * Vref + 9 (Vref = 0 .. 3.7 V) Lower limit : IP = -80 (Vref = 3.7 .. 4 V) Page 15/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **External reference voltage (continued)** **==> picture [216 x 168] intentionally omitted <==** **----- Start of picture text -----**<br> 100<br>80<br>60<br>40<br>20<br>0<br>-20<br>-40<br>-60<br>-80 CASR 25<br>-100<br>0 1 2 3 4<br>VREF (V)<br> (A)<br>P<br> I<br>**----- End of picture text -----**<br> **==> picture [215 x 167] intentionally omitted <==** **----- Start of picture text -----**<br> 200<br>150<br>100<br>50<br>0<br>-50<br>-100<br>-150 CASR 50<br>-200<br>0 1 2 3 4<br>VREF (V)<br> (A)<br>P<br> I<br>**----- End of picture text -----**<br> Upper limit : **I** P = -40 * Vref + 185 (Vref = 2.5 .. 4 V) Upper limit : **I** P = 85 (Vref = 0 .. 2.5 V) Lower limit : **I** P = -40 * Vref + 15 (Vref = 0 .. 2.5 V) Lower limit : **I** P = -85 (Vref = 2.5 .. 4 V) Upper limit : **I** P = -80 * Vref + 370 (Vref = 2.75 .. 4 V) Upper limit : **I** P = 150 (Vref = 0 .. 2.75 V) Lower limit : **I** P = -80 * Vref + 30 (Vref = 0 .. 2.25 V) Lower limit : **I** P = -150 (Vref = 2.25 .. 4 V) ## _Example with V_ REF _= 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 V_ REF _= 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 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com **CASR series** ## **CASR Series, PCB footprint** **==> picture [250 x 241] intentionally omitted <==** ## **Assembly on PCB** - ●Recommended PCB hole diameter 1.3 mm for primary pin - ●Maximum PCB thickness - ●Wave soldering profile No clean process only. 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 17/18 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** **Dimensions CASR Series** (in mm. General linear tolerance ± 0.25 mm) **==> picture [51 x 8] intentionally omitted <==** **----- Start of picture text -----**<br> Connection<br>**----- End of picture text -----**<br> Page 18/18 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 8March2012/version 7 www.lem.com
Updated at June 10, 2026
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