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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
● 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 coefcient 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 50178
●UL 508
● IEC 61010-1 (safety).
Application Domain
● Industrial.
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CASR series
Absolute maximum ratings
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 50/60Hz/1 min VdkV 4.1
Impulse withstand voltage 1.2/50 µs VwkV 7.5
Partial discharge extinction voltage @ 10 pC (rms) VeV1000
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
Case material - - V0 according
to UL 94
Comparative tracking index CTI V600
Application example - - 300 V CAT III
PD2
Reinforced isolation, non
uniform eld according to
EN 50178, EN 61010
Application example - - 600 V CAT III
PD2
Simple isolation, non
uniform eld according to
EN 50178, EN 61010
According to UL 508:
primary potential involved in Volts RMS AC or DC -V600 For use in a pollution
degree 2 environment
Environmental and mechanical characteristics
Parameter Symbol Unit Min Typ Max Comment
Ambient operating temperature TA°C -40 85
Ambient storage temperature TS°C -55 105
Mass mg 9
Standards EN 50178, IEC 60950-1, IEC 61010-1, IEC 61326-1, UL 508
Parameter Symbol Unit Value
Supply voltage VCV 7
Primary conductor temperature °C 110
Maximum primary current IP max A20 x IPN
ESD rating, Human Body Model (HBM) kV 4
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CASR series
Electrical data CASR 6-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter Symbol Unit Min Typ Max Comment
Primary nominal current rms IPN A 6
Primary current, measuring range IPM A-20 20
Number of primary turns NP-1,2,3
Supply voltage VCV4.75 55.25
Current consumption ICmA 15 + 20 + NS = 1731 turns
Reference voltage @ IP = 0 A VREF V2.495 2.5 2.505 Internal reference
External reference voltage VREF V 0 4
Output voltage VOUT V0.375 4.625
Output voltage @ IP = 0 A VOUT VVREF
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 coefcient of VREF TCVREF ppm/K ±5 ±50 Internal reference
Temperature coefcient of VOUT
@ IP = 0 A TCVOUT ppm/K ±6 ±14 ppm/K of 2.5 V
- 40°C .. 85°C
Theoretical sensitivity Gth mV/A 104.2 625 mV/ IPN
Sensitivity error εG%-0.7 0.7 100% tested
Temperature coefcient of GTCG ppm/K ±40 - 40°C .. 85°C
Linearity error εL% 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 µA/Hz½20 RL = 1 kΩ
Peak-peak output ripple at oscillator
frequency f = 450 kHz (typ.) -mV 40 160 RL = 1 kΩ
Reaction time @ 10 % of IPN tra µs 0.3 RL = 1 kΩ
di/dt = 18 A/µs
Response time @ 90 % of IPN trµs 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 XG% of IPN 2.2
Accuracy X% of IPN 0.8
Accuracy @ TA = 85°C X% of IPN 1.4
IP (mA)
NS
IP (mA)
NS
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CASR series
Electrical data CASR 15-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter Symbol Unit Min Typ Max Comment
Primary nominal current rms IPN A15
Primary current, measuring range IPM A-51 51
Number of primary turns NP-1,2,3
Supply voltage VCV4.75 55.25
Current consumption ICmA 15 + 20 + NS = 1731 turns
Reference voltage @ IP = 0 A VREF V2.495 2.5 2.505 Internal reference
External reference voltage VREF V 0 4
Output voltage VOUT V0.375 4.625
Output voltage @ IP = 0 A VOUT VVREF
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 coefcient of VREF TCVREF ppm/K ±5 ±50 Internal reference
Temperature coefcient of VOUT
@ IP = 0 A TCVOUT ppm/K ±2.3 ±6 ppm/K of 2.5 V
- 40°C .. 85°C
Theoretical sensitivity Gth mV/A 41.67 625 mV/ IPN
Sensitivity error εG%-0.7 0.7 100% tested
Temperature coefcient of GTCG ppm/K ±40 - 40°C .. 85°C
Linearity error εL% 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 µA/Hz½20 RL = 1 kΩ
Peak-peak output ripple at oscillator
frequency f = 450 kHz (typ.) -mV 15 60 RL = 1 kΩ
Reaction time @ 10 % of IPN tra µs 0.3 RL = 1 kΩ
di/dt = 44 A/µs
Response time @ 90 % of IPN trµs 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 XG% of IPN 1.5
Accuracy X% of IPN 0.8
Accuracy @ TA = 85°C X% of IPN 1.2
IP (mA)
NS
IP (mA)
NS
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CASR series
Electrical data CASR 25-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter Symbol Unit Min Typ Max Comment
Primary nominal current rms IPN A25
Primary current, measuring range IPM A-85 85
Number of primary turns NP-1,2,3
Supply voltage VCV4.75 55.25
Current consumption ICmA 15 + 20 + NS = 1731 turns
Reference voltage @ IP = 0 A VREF V2.495 2.5 2.505 Internal reference
External reference voltage VREF V 0 4
Output voltage VOUT V0.375 4.625
Output voltage @ IP = 0 A VOUT VVREF
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 coefcient of VREF TCVREF ppm/K ±5 ±50 Internal reference
Temperature coefcient of VOUT
@ IP = 0 A TCVOUT ppm/K ±1.4 ±4 ppm/K of 2.5 V
- 40°C .. 85°C
Theoretical sensitivity Gth mV/A 25 625 mV/ IPN
Sensitivity error εG
%-0.7 0.7 100% tested
Temperature coefcient of GTCG ppm/K ±40 - 40°C .. 85°C
Linearity error εL% 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 µA/Hz½20 RL = 1 kΩ
Peak-peak output ripple at oscillator
frequency f = 450 kHz (typ.) -mV 10 40 RL = 1 kΩ
Reaction time @ 10 % of IPN tra µs 0.3 RL = 1 kΩ
di/dt = 68 A/µs
Response time @ 90 % of IPN trµs 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 XG% of IPN 1.35
Accuracy X% of IPN 0.8
Accuracy @ TA = 85°C X% of IPN 1.15
IP (mA)
NS
IP (mA)
NS
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CASR series
Electrical data CASR 50-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter Symbol Unit Min Typ Max Comment
Primary nominal current rms IPN A50
Primary current, measuring range IPM A-150 150
Number of primary turns NP-1,2,3
Supply voltage VCV4.75 55.25
Current consumption ICmA 15 + 20 + NS = 966 turns
Reference voltage @ IP = 0 A VREF V2.495 2.5 2.505 Internal reference
External reference voltage VREF V 0 4
Output voltage VOUT V0.375 4.625
Output voltage @ IP = 0 A VOUT VVREF
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 coefcient of VREF TCVREF ppm/K ±5 ±50 Internal reference
Temperature coefcient of VOUT
@ IP = 0 A TCVOUT ppm/K ±0.7 ±3 ppm/K of 2.5 V
- 40°C .. 85°C
Theoretical sensitivity Gth mV/A 12.5 625 mV/ IPN
Sensitivity error εG
%-0.7 0.7 100% tested
Temperature coefcient of GTCG ppm/K ±40 - 40°C .. 85°C
Linearity error εL% 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 µA/Hz½20 RL = 1 kΩ
Peak-peak output ripple at oscillator
frequency f = 450 kHz (Typ.) -mV 520 RL = 1 kΩ
Reaction time @ 10 % of IPN tra µs 0.3 RL = 1 kΩ
di/dt = 100 A/µs
Response time @ 90 % of IPN trµs 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 XG% of IPN 1.2
Accuracy X% of IPN 0.8
Accuracy @ TA = 85°C X% of IPN 1.1
IP (mA)
NS
IP (mA)
NS
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CASR series
Typical performance characteristics CASR 6-NP
Figure 1: Linearity error Figure 2: Frequency response
Figure 3: Step response Figure 4: Step response
Figure 5: Input referred noise Figure 6: dv/dt
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
100 1000 10000 100000 1000000
Frequency (Hz)
Relative Sensitivity (dB)
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
Phase (°)
Relative
Sensitivity
Phase
IP = 6 A
-1
0
1
2
3
4
5
6
7
-0.5 00.5 11.5 2
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
IP
VOU T
IP = 6 A
-1
0
1
2
3
4
5
6
7
-2 0 2 4 6 8 10
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 6 A
-0.1
-0.05
0
0.05
0.1
-6 0 6
IP (A)
Linearity error (% of I
PN)
-800
-600
-400
-200
0
200
400
600
800
-1 012345
t (µs)
Primary Voltage VP (V)
2.4
2.6
2.8
3.0
3.2
3.4
3.6
VOUT (V)
VP
VOU T
VREF
20 kV/μs
0.1
1
10
100
1000
10000
1. E+1 1. E+2 1. E+3 1. E+4 1 .E+5 1. E+6 1 .E+7
Frequency (Hz)
ino (μA/Hz
½)
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CASR series
Typical performance characteristics CASR 15-NP
Figure 7: Linearity error Figure 8: Frequency response
Figure 9: Step response Figure 10: Step response
Figure 11: Input referred noise Figure 12: dv/dt
-0.1
-0.05
0
0.05
0.1
-15 015
IP (A)
Linearity error (% of I
PN)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
100 1000 10000 100000 1000000
Frequency (Hz)
Relative Sensitivity (dB)
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
Phase (°)
Relative
Sensitivity
Phase
IP = 15 A
-800
-600
-400
-200
0
200
400
600
800
-1 012345
t (µs)
Primary Voltage VP (V)
2.4
2.6
2.8
3.0
3.2
3.4
3.6
VOUT (V)
VP
VOU T
VREF
20 kV/μs
-2.5
0
2.5
5
7.5
10
12.5
15
17.5
-0.5 00.5 11.5 2
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 15 A
-2.5
0
2.5
5
7.5
10
12.5
15
17.5
-2 0 2 4 6 8 10
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 15 A
0.1
1
10
100
1000
10000
1. E+1 1. E+2 1. E+3 1. E+4 1 .E+5 1. E+6 1 .E+7
Frequency (Hz)
ino (μA/Hz
½)
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CASR series
Typical performance characteristics CASR 25-NP
Figure 13: Linearity error Figure 14: Frequency response
Figure 15: Step response Figure 16: Step response
Figure 17: Input referred noise Figure 18: dv/dt
-0.1
-0.05
0
0.05
0.1
-25 025
IP (A)
Linearity error (% of I
PN)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
100 1000 10000 100000 1000000
Frequency (Hz)
Relative Sensitivity (dB)
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
Phase (°)
Relative
Sensitivity
Phase
IP = 25 A
-4.2
0.0
4.2
8.3
12.5
16.7
20.8
25.0
29.2
-0.5 00.5 11.5 2
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 25 A
-4.2
0.0
4.2
8.3
12.5
16.7
20.8
25.0
29.2
-2 0246810
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 25 A
-800
-600
-400
-200
0
200
400
600
800
-1 012345
t (µs)
Primary Voltage VP (V)
2.4
2.6
2.8
3.0
3.2
3.4
3.6
VOUT (V)
VP
VOU T
VREF
20 kV/μs
0.1
1
10
100
1000
10000
1. E+1 1. E+2 1. E+3 1. E+4 1 .E+5 1. E+6 1 .E+7
Frequency (Hz)
ino (μA/Hz
½)
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CASR series
Typical performance characteristics CASR 50-NP
Figure 19: Linearity error Figure 20: Frequency response
Figure 21: Step response Figure 22: Step response
Figure 23: Input referred noise Figure 24: dv/dt
-0.1
-0.05
0
0.05
0.1
-50 050
IP (A)
Linearity error (% of I
PN)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
100 1000 10000 100000 1000000
Frequency (Hz)
Relative Sensitivity (dB)
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
Phase (°)
Relative
Sensitivity
Phase
IP = 50 A
-8.3
0.0
8.3
16.7
25.0
33.3
41.7
50.0
58.3
-2 0246810
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 50 A
-800
-600
-400
-200
0
200
400
600
800
-1 012345
t (µs)
Primary Voltage VP (V)
2.4
2.6
2.8
3.0
3.2
3.4
3.6
VOUT (V)
VP
VOU T
VREF
20 kV/μs
-8.3
0.0
8.3
16.7
25.0
33.3
41.7
50.0
58.3
-0.5 00.5 11.5 2
t (µs)
IP (A)
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
VOUT (V)
IP
VOU T
IP = 50 A
0.1
1
10
100
1000
10000
1. E+1 1. E+2 1 .E+3 1. E+4 1 .E+5 1 .E+6 1 .E+7
Frequency (Hz)
ino (μA/Hz
½)
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CASR series
Maximum continuous DC primary current
Figure 25: IP vs TA for CASR 6-NP Figure 26: IP vs TA for CASR 15-NP
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
Figure 29: Maximum RMS AC primary current / maximum DC primary current vs frequency
AC Derating
10
100
1M
1k
10k
100k
0
0.25
0.5
0.75
1
1.25
f (Hz)
max RMS AC current /
max DC current
CASR 6-NP
0
5
10
15
20
25
30
35
40
020 40 60 80 100 120
TA (°C)
IP (A)
CASR 15-NP
0
10
20
30
40
50
60
70
80
90
020 40 60 80 100 120
TA (°C)
IP (A)
CASR 25-NP
0
10
20
30
40
50
60
70
80
90
020 40 60 80 100 120
TA (°C)
IP (A)
CASR 50-NP
0
20
40
60
80
100
120
140
160
020 40 60 80 100 120
TA (°C)
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CASR series
Ampere-turns and amperes
The transducer is sensitive to the primary current linkage
QP (also called ampere-turns).
 Q
P=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 simplied model
The static model of the transducer at temperature TA is:
VOUT = G QP + error
In which error =
VOE + VOT (TA) + εG ·QP·G + εL(QPmax)·QPmax·G + TCG·(TA-25)·QP·G
With: QP = NPIP :the input ampere-turns (At)
Please read above warning.
QPmax :the maxi input ampere-turns that have
been applied to the transducer (At)
VOUT :the secondary voltage (V)
TA :the ambient temperature (°C)
VOE :the electrical offset voltage (V)
VOT(TA) :the temperature variation of VO at
temperature TA (V)
G :the sensitivity of the transducer (V/At)
ε
G :the sensitivity error
ε
L (QPmax) :the linearity error for QPmax
This model is valid for primary ampere-turns QP between
-QPmax and +QPmax only.
Performance parameters denition
Sensitivity and linearity
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 dened as the slope of the linear regres-
sion 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.
Magnetic offset
The magnetic offset current IOM is the consequence of a cur-
rent on the primary side (“memory effect” of the transducer’s
ferro-magnetic parts). It is included in the linearity gure but
can be measured individually.
It is measured using the following primary current cycle.
IOM depends on the current value IP1.
Figure 30: Current cycle used to measure magnetic and
electrical offset (transducer supplied)
IP (DC)
-IP1
IP1
0 A
t1 t
t Ip(3)
t2
Ip(
3)
Gth
tVtV
IOUTOUT
OM
1
2
)()( 21 ⋅
−
=
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CASR series
Overall accuracy
The overall accuracy at 25°C XG is the error in the - IPN .. + IPN
range, relative to the rated value IPN.
It includes:
● the electrical offset VOE
●the sensitivity error εG
● the linearity error εL (to IPN)
The magnetic offset is part of the overall accuracy. It is taken
into account in the linearity error gure 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
gure 31.
Both depend on the primary current di/dt. They are measured
at nominal ampere-turns.
Figure 32: Response time tr and reaction time tra
Electrical offset
The electrical offset voltage VOE can either be measured when
the ferro-magnetic parts of the transducer are:
● completely demagnetized, which is difcult to realize,
● or in a known magnetization state, like in the current cycle
shown in gure 30.
Using the current cycle shown in gure 30, the electrical offset
is:
The temperature variation VOT of the electrical offset voltage
VOE is the variation of the electrical offset from 25°C to the
considered temperature:
Note: the transducer has to be demagnetized prior to the
application of the current cycle (for example with a
demagnetization tunnel).
Figure 31: Test connection
Performance parameters denition (continued)
2
)()( 21 tVtV
VOUTOUT
OE
+
=
)25()()( CVTVTV
OEOEOT
°−=
t
ra
V
OUT
t
r
90 %
10 %
t
100 %
I
p
I
1 2 3
10 9 8
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CASR series
1 2 3
10 9 8
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)
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.
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.Application information
Application information
Number of
primary turns
Primary
resistance
RP [mW]
Recommended
connections
10.24
10 9 8 OUT
IN 1 2 3
21.08
10 9 8 OUT
IN 1 2 3
32.16
10 9 8 OUT
IN 1 2 3
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CASR series
External reference voltage
If the Ref pin of the transducer is not used it could be either left unconnected or ltered 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 specied 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
680
5.2−Vref , the maximum value will be 2.2 mA typ. when Vref = 4 V.
- or to sink a typical current of
680
5.2 Vref−
, the maximum value will be 3.68 mA typ. when Vref = 0 V.
The following graphs show how the measuring range of each transducer version depends on the external reference voltage
value Vref.
Upper limit : IP = -9.6 * Vref + 44.4 (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 = -9.6 * Vref + 3.6 (Vref = 0 .. 4 V) Lower limit : IP = -24 * Vref + 9 (Vref = 0 .. 3.7 V)
Lower limit : IP = -80 (Vref = 3.7 .. 4 V)
Application information (continued)
-50
-40
-30
-20
-10
0
10
20
30
40
50
01234
VREF (V)
I P (A)
CASR 6
-100
-80
-60
-40
-20
0
20
40
60
80
100
01234
I P (A)
VREF (V)
CASR 15
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CASR series
External reference voltage (continued)
Upper limit : IP = -40 * Vref + 185 (Vref = 2.5 .. 4 V) Upper limit : IP = -80 * Vref + 370 (Vref = 2.75 .. 4 V)
Upper limit : IP = 85 (Vref = 0 .. 2.5 V) Upper limit : IP = 150 (Vref = 0 .. 2.75 V)
Lower limit : IP = -40 * Vref + 15 (Vref = 0 .. 2.5 V) Lower limit : IP = -80 * Vref + 30 (Vref = 0 .. 2.25 V)
Lower limit : IP = -85 (Vref = 2.5 .. 4 V) Lower limit : IP = -150 (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
-100
-80
-60
-40
-20
0
20
40
60
80
100
01234
VREF (V)
I P (A)
CASR 25
-200
-150
-100
-50
0
50
100
150
200
01234
VREF (V)
I P (A)
CASR 50
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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 prole maximum 260°C 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.
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CASR series
Dimensions CASR Series (in mm. General linear tolerance ± 0.25 mm)
Connection