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 isolation
between the primary and the secondary circuit.
Features
Applications
●● Closed loop (compensated) multi-range
●● AC variable speed and servo motor drives
●● Static converters for DC motor drives
current transducer
●● Voltage output
●● Battery supplied applications
●● Single supply
●● Uninterruptible Power Supplies (UPS)
●● Isolated plastic case material recognized
●● Switched Mode Power Supplies (SMPS)
●● Power supplies for welding applications
according to UL 94-V0
●● Compact design for PCB mounting.
●● Solar inverters.
Advantages
Standards
●● Very low temperature coefficient of offset
●● EN 50178
●● Very good dv/dt immunity
●● UL 508
●● Higher creepage / clearance distances
●● IEC 61010-1 (safety).
●● Reduced height
●● Reference pin with two modes: Ref IN and Ref OUT
●● Extended measuring range for unipolar measurement.
Application Domain
●● Industrial.
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CKSR series
Absolute maximum ratings
Parameter
Symbol
Unit
Value
VC
V
7
°C
110
A
20 x IPN
kV
4
Supply voltage
Primary conductor temperature
Maximum primary current
IP max
ESD rating, Human Body Model (HBM)
Stresses above these ratings may cause permanent damage. Exposure to absolute maximum ratings for extended periods may
degrade reliability.
Isolation characteristics
Parameter
Symbol
Unit
Value
RMS voltage for AC isolation test 50/60Hz/1 min
Vd
kV
4.3
Impulse withstand voltage 1.2/50 µs
Vw
kV
8
Partial discharge extinction voltage @ 10 pC (rms)
Ve
V
1000
Clearance distance (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
-
-
Reinforced isolation, non
300 V CAT III
uniform field according to
PD2
EN 61010
Application example
-
-
Reinforced isolation, non
600 V CAT III
uniform field according to
PD2
EN 50178
Application example
-
-
1000 V CAT
III PD2
According to UL 508:
primary potential
involved in Volts
RMS AC or DC
-
V
600
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
Simple isolation, non
uniform field according to
EN 50178
For use in a pollution
degree
2 environment
Environmental and mechanical characteristics
Parameter
Standards
Typ
Max
Comment
9
EN 50178, IEC 60950-1, IEC 61010-1, IEC 61326-1, UL 508
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CKSR series
Electrical data CKSR 6-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter
Max
Comment
Unit
Primary nominal current rms
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
-
Supply voltage
VC
V
Current consumption
IC
mA
Reference voltage @ IP = 0 A
VREF
V
2.495
External reference voltage
VREF
V
0
4
Output voltage
VOUT
V
0.375
4.625
Output voltage @ IP = 0 A
VOUT
V
VOE
mV
-5.3
5.3
100% tested
VOUT - VREF
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
Theoretical sensitivity
Gth
mV/A
104.2
Sensitivity error
εG
%
TCG
ppm/K
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) rms100 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
Response time @ 90 % of IPN
Electrical offset voltage
Electrical offset current referred to
primary
Temperature coefficient of G
Min
Typ
Symbol
Apply derating according
to fig. 25
6
-20
20
1,2,3,4
4.75
5
15 +
5.25
I (mA)
IP (mA)
20 + P N
NS = 1731 turns
NS
S
2.5
2.505
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
Accuracy
X
% of IPN
0.8
Accuracy @ TA = 85°C (105°C)
X
% of IPN
1.4
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CKSR series
Electrical data CKSR 15-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter
Max
Comment
Unit
Primary nominal current rms
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
-
Supply voltage
VC
V
Current consumption
IC
mA
Reference voltage @ IP = 0 A
VREF
V
2.495
External reference voltage
VREF
V
0
4
Output voltage
VOUT
V
0.375
4.625
Output voltage @ IP = 0 A
VOUT
V
Electrical offset voltage
VOE
mV
-2.21
2.21
100% tested
VOUT - VREF
Electrical offset current referred to
primary
IOE
mA
-53
53
100% tested
Temperature coefficient of VREF
TCVREF
ppm/K
±5
±50
Internal reference
Temperature coefficient of VOUT
@ IP = 0 A
TCVOUT
ppm/K
±2.3
±6
ppm/K of 2.5 V
- 40°C .. 105°C
Theoretical sensitivity
Gth
mV/A
41.67
Sensitivity error
εG
%
TCG
ppm/K
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/Hz½
20
Peak-peak output ripple at
oscillator frequency f = 450 kHz
(typ.)
-
mV
15
Reaction time @ 10 % of IPN
tra
Response time @ 90 % of IPN
Temperature coefficient of G
Min
Typ
Symbol
15
-51
Apply derating according
to fig. 26
51
1,2,3,4
4.75
5
15 +
5.25
I (mA)
IP (mA)
20 + P
NS
NS
2.5
2.505
NS = 1731 turns
Internal reference
VREF
-0.7
625 mV/ IPN
0.7
100% tested
±40
- 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
Accuracy
X
% of IPN
0.8
Accuracy @ TA = 85°C (105°C)
X
% of IPN
1.2
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CKSR series
Electrical data CKSR 25-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter
Typ
Comment
Unit
Primary nominal current rms
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
-
Supply voltage
VC
V
Current consumption
IC
mA
Reference voltage @ IP = 0 A
VREF
V
2.495
External reference voltage
VREF
V
0
4
Output voltage
VOUT
V
0.375
4.625
Output voltage @ IP = 0 A
VOUT
V
VOE
mV
-1.35
1.35
100% tested
VOUT - VREF
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
Theoretical sensitivity
Gth
mV/A
25
Sensitivity error
εG
%
TCG
ppm/K
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/Hz½
20
Peak-peak output ripple at
oscillator frequency f = 450 kHz
(typ.)
-
mV
10
Reaction time @ 10 % of IPN
tra
Response time @ 90 % of IPN
Electrical offset voltage
Electrical offset current referred to
primary
Temperature coefficient of G
Min
Max
Symbol
25
Apply derating according
to fig. 27
-85
85
1,2,3,4
4.75
5
15 +
IP (mA)
NS
2.5
5.25
20 +
IP (mA)
NS NS = 1731 turns
2.505
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
Accuracy
X
% of IPN
0.8
Accuracy @ TA = 85°C (105°C)
X
% of IPN
1.15
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CKSR series
Electrical data CKSR 50-NP
At TA = 25°C, VC = + 5 V, NP = 1 turn, RL = 10 kΩ, internal reference, unless otherwise noted.
Parameter
Typ
Comment
Unit
Primary nominal current rms
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
-
Supply voltage
VC
V
Current consumption
IC
mA
Reference voltage @ IP = 0 A
VREF
V
2.495
External reference voltage
VREF
V
0
4
Output voltage
VOUT
V
0.375
4.625
Output voltage @ IP = 0 A
VOUT
V
Electrical offset voltage
VOE
mV
-0.725
0.725
100% tested
VOUT - VREF
Electrical offset current
referred to primary
IOE
mA
-58
58
100% tested
Temperature coefficient of VREF
TCVREF
ppm/K
±5
±50
Internal reference
Temperature coefficient of VOUT
@ IP = 0 A
TCVOUT
ppm/K
±0.7
±3
ppm/K of 2.5 V
- 40°C .. 105°C
Theoretical sensitivity
Gth
mV/A
12.5
Sensitivity error
εG
%
TCG
ppm/K
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/Hz½
20
Peak-peak output ripple at
oscillator frequency f = 450 kHz
(typ.)
-
mV
5
Reaction time @ 10 % of IPN
tra
Response time @ 90 % of IPN
Temperature coefficient of G
Min
Max
Symbol
Apply derating according to
fig. 28
50
-150
150
1,2,3,4
4.75
5
15 +
5.25
IP (mA)
I (mA)
20 + P
NS = 966 turns
NS
NS
2.5
2.505
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
Accuracy
X
% of IPN
0.8
Accuracy @ TA = 85°C (105°C)
X
% of IPN
1.1
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CKSR series
0.05
0
-0.05
-0.1
0
IP (A)
6
1000
10000 100000 1000000
Frequency (Hz)
Figure 2: Frequency response
7
3.2
7
3.2
6
3.1
6
3.1
5
3.0
5
3.0
2.9
4
3
2.8
2
IP
2.7
1
VOUT
2.6
0
-1
-0.5
0
0.5
1
1.5
2.8
2
IP
2.7
1
VOUT
2.6
2.5
0
2.5
2.4
-1
2.4
-2
2
0
2
4
6
8
10
t (µs)
t (µs)
Figure 3: Step response
Figure 4: Step response
10000
Primary Voltage VP (V)
800
1000
½
2.9
IP = 6 A
3
100
10
3.6
600
3.4
400
3.2
200
0
-200
VP
VOUT
VREF
-400
1
3.0
20 kV/μs
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
Frequency (Hz)
Figure 5: Input referred noise VOUT (V)
IP = 6 A
IP (A)
4
VOUT (V)
IP (A)
Relative
Sensitivity
Phase
100
Figure 1: Linearity error
ino (μA/Hz )
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
IP = 6 A
VOUT (V)
-6
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
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CKSR series
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
Relative Sensitivity (dB)
0
-0.05
-0.1
-15
0
IP (A)
Relative
Sensitivity
Phase
100
15
Figure 7: Linearity error
1000
10000 100000 1000000
Frequency (Hz)
Figure 8: Frequency response
3.2
15
3.1
15
3.1
12.5
3.0
12.5
3.0
10
2.9
IP = 15 A
7.5
5
2.5
2.8
2.7
VOUT
2.6
2.5
2.5
0
2.4
-2.5
-2.5
0
0.5
1
10
1.5
5
2
2.7
VOUT
2.6
0
2
4
6
8
10
t (µs)
Figure 10: Step response
800
Primary Voltage VP (V)
1000
½
IP
2.4
-2
10000
ino (μA/Hz )
2.8
2.5
t (µs)
Figure 9: Step response
2.9
IP = 15 A
7.5
IP
0
-0.5
IP (A)
17.5
VOUT (V)
3.2
IP (A)
17.5
100
10
3.6
600
3.4
400
3.2
200
0
3.0
20 kV/μs
-200
VP
VOUT
VREF
-400
1
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)
0.05
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
IP = 15 A
VOUT (V)
Linearity error (% of IPN)
0.1
Phase (°)
Typical performance characteristics CKSR 15-NP
1
2
3
4
5
t (µs)
Figure 12: dv/dt
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CKSR series
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
Relative Sensitivity (dB)
0.05
0
-0.05
-0.1
0
Relative
Sensitivity
Phase
100
25
IP (A)
Figure 13: Linearity error
1000
10000 100000 1000000
Frequency (Hz)
Figure 14: Frequency response
3.2
29.2
3.2
25.0
3.1
25.0
3.1
20.8
3.0
20.8
3.0
2.9
16.7
IP (A)
IP = 25 A
12.5
2.8
2.9
IP = 25 A
IP (A)
16.7
VOUT (V)
29.2
12.5
2.8
8.3
IP
2.7
2.6
4.2
VOUT
2.6
0.0
2.5
0.0
-4.2
2.4
-4.2
8.3
IP
2.7
4.2
VOUT
-0.5
0
0.5
1
1.5
2.5
2.4
-2
2
0
2
6
8
10
Figure 16: Step response
800
Primary Voltage VP (V)
10000
1000
ino (μA/Hz½)
4
t (µs)
t (µs)
Figure 15: Step response
100
10
3.6
600
3.4
400
3.2
200
0
3.0
20 kV/μs
-200
VP
VOUT
VREF
-400
1
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 17: Input referred noise VOUT (V)
-25
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
IP = 25 A
VOUT (V)
Linearity error (% of IPN)
0.1
Phase (°)
Typical performance characteristics CKSR 25-NP
1
2
3
4
5
t (µs)
Figure 18: dv/dt
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CKSR series
Relative Sensitivity (dB)
0
-0.05
-0.1
-50
0
Relative
Sensitivity
Phase
100
50
IP (A)
Figure 19: Linearity error
1000
10000 100000 1000000
Frequency (Hz)
Figure 20: Frequency response
3.2
58.3
3.2
50.0
3.1
50.0
3.1
41.7
3.0
41.7
3.0
2.9
33.3
25.0
16.7
2.8
2.7
IP
VOUT
8.3
0.0
-8.3
-0.5
0
0.5
1
1.5
25.0
16.7
2.6
8.3
2.5
0.0
2.4
-8.3
2
2.7
VOUT
2.6
2.4
-2
0
2
4
6
8
10
t (µs)
Figure 22: Step response
800
Primary Voltage VP (V)
10000
1000
ino (μA/Hz )
2.8
IP
2.5
t (µs)
Figure 21: Step response
2.9
IP = 50 A
IP (A)
IP (A)
IP = 50 A
VOUT (V)
58.3
33.3
½
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
IP = 50 A
100
10
3.6
600
3.4
400
3.2
200
0
3.0
20 kV/μs
-200
VP
VOUT
VREF
-400
1
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 23: Input referred noise VOUT (V)
0.05
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
VOUT (V)
Linearity error (% of IPN)
0.1
Phase (°)
Typical performance characteristics CKSR 50-NP
1
2
3
4
5
t (µs)
Figure 24: dv/dt
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CKSR series
Maximum continuous DC primary current
40
90
30
25
IP (A)
IP (A)
CKSR 15-NP
80
70
CKSR 6-NP
35
20
15
60
50
40
30
10
20
10
5
0
0
0
20
40
60
80
100
120
0
20
40
TA (°C)
Figure 25: IP vs TA for CKSR 6-NP
80
100
120
Figure 26: IP vs TA for CKSR 15-NP
90
160
80
70
140
60
50
100
CKSR 50-NP
120
IP (A)
IP (A)
60
TA (°C)
40
30
80
60
40
CKSR 25-NP
20
10
20
0
0
0
20
40
60
80
100
0
120
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 x rated power
Frequency derating
AC Derating
max RMS AC current /
max DC current
1.25
1
0.75
0.5
0.25
0
10
100
1k
10k
100k
1M
f (Hz)
Figure 29: Maximum RMS AC primary current / maximum DC primary current vs frequency
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Performance parameters definition
Ampere-turns and amperes
The transducer is sensitive to the primary current linkage
QP (also called ampere-turns).
QP=NPIP(At)
Where NPIP is the number of primary turn (1, 2 , 3
or 4 depending on the connection of the primary
jumpers)
Caution: As most applications will use the transducer with
only one single primary turn (NP = 1), much of this datasheet
is written in terms of primary current instead of current
linkages. However, the ampere-turns (A-t) unit is used to
emphasis that current linkages are intended and applicable.
Transducer simplified model
The static model of the transducer at temperature TA is:
VOUT = G QP + error
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 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.
Magnetic offset
The magnetic offset current IOM is the consequence of a current on the primary side (“memory effect” of the transducer’s
ferro-magnetic parts). It is included in the linearity figure but
can be measured individually.
It is measured using the following primary current cycle.
IOM depends on the current value IP1.
In which error =
I
VOE + VOT (TA) + εG ·QP·G + εL(QPmax)·QPmax·G + TCG·(TA-25)·QP·G
With:
QP = NPIP
QPmax
VOUT
TA
VOE
VOT(TA)
G
εG
εL (QPmax)
:the input ampere-turns (At)
Please read above warning.
:the maxi input ampere-turns that have
been applied to the transducer (At)
:the secondary voltage (V)
:the ambient temperature (°C)
:the electrical offset voltage (V)
:the temperature variation of VO at
temperature TA (V)
:the sensitivity of the transducer (V/At)
:the sensitivity error
:the linearity error for QPmax
OM
=
V (t ) − V (t ) 1
⋅
2
Gth
OUT
1
OUT
2
IP (DC)
IP1
0A
-IP1
t
t1
Ip(3)
t2
Ip(t
3)
Figure 30: Current cycle used to measure magnetic and
electrical offset (transducer supplied)
This model is valid for primary ampere-turns QP between
-QPmax and +QPmax only.
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CKSR series
Performance parameters definition (continued)
Electrical offset
Overall accuracy
●● completely demagnetized, which is difficult to realize,
It includes:
●● or in a known magnetization state, like in the current cycle
●● the electrical offset VOE
●● the sensitivity error eG
●● the linearity error eL (to IPN)
The magnetic offset is part of the overall accuracy. It is taken
into account in the linearity error figure provided the
transducer has not been magnetized by a current higher than
IPN.
The electrical offset voltage VOE can either be measured when
the ferro-magnetic parts of the transducer are:
shown in figure 30.
Using the current cycle shown in figure 30, the electrical
offset is:
V =
OE
V (t ) + V (t )
2
OUT
1
OUT
2
The temperature variation VOT of the electrical offset
voltage VOE is the variation of the electrical offset from 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 overall accuracy at 25°C XG is the error in the - IPN .. + IPN
range, relative to the rated value 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.
100 %
90 %
I
VOUT
Ip
tr
10 %
tra
Figure 31: Test connection
t
Figure 32: response time tr and reaction time tra
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CKSR series
Application information
Filtering and decoupling
Supply voltage VC
Reference VREF
The fluxgate oscillator draws current pulses of up to 30 mA at
a rate of ca. 900 kHz. Significant 900 kHz voltage ripple on
VC can indicate a power supply with high impedance. At these
frequencies the power supply rejection ratio is low, and the ripple may appear on the transducer output VOUT and reference
VREF. The transducer has internal decoupling capacitors, but in
the case of a power supply with high impedance, it is advised
to provide local decoupling (100 nF or more, located close to
the transducer)
Ripple present on the reference output can be filtered with a
low value of capacitance because of the internal 680 Ohm
series resistance. The maximum filter capacitance value is
1 µF
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 [mW]
1
0.18
2
4
Recommended
connections
9
8
7
6
OUT
IN
2
9
3
8
4
7
5
6 OUT
IN
2
9
3
8
4
7
5
6 OUT
IN
2
3
4
5
0.72
2.88
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CKSR series
Application information (continued)
External reference voltage
If the Ref pin of the transducer is not used it could be either left unconnected or filtered according to the previous paragraph
“Reference VREF”.
The Ref pin has two modes Ref IN and Ref OUT:
●● In the Ref OUT mode the 2.5 V internal precision reference is used by the transducer as the reference point for bipolar
measurements; this internal reference is connected to the Ref pin of the transducer through a 680 Ohms resistor. it tolerates
sink or source currents up to ± 5 mA, but the 680 Ohms resistor prevents this current to exceed these limits.
●● In the Ref IN mode, an external reference voltage is connected to the Ref pin; this voltage is specified in the range 0 to 4 V
and is directly used by the transducer as the reference point for measurements.
The external reference voltage VREF must be able:
- either to source a typical current of
- or to sink a typical current of
Vref − 2.5
, the maximum value will be 2.2 mA typ. when VREF= 4 V.
680
2.5 − Vref
680
, the maximum value will be 3.68 mA typ. when VREF = 0 V.
50
40
30
20
10
0
-10
-20
-30
-40
-50
I P (A)
I P (A)
The following graphs show how the measuring range of each transducer version depends on the external reference voltage
value VREF.
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)
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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)
3
4
Upper limit : IP = -80 * VREF + 370 (VREF = 2.75 .. 4 V)
Upper limit : IP = 150
(VREF = 0 .. 2.75 V)
Lower limit : IP = -80 * VREF + 30 (VREF= 0 .. 2.25 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
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CKSR Series, PCB footprint
CKSR series
Assembly on PCB
●● Recommended PCB hole diameter 1.3 mm for primary pin
0.8 mm for secondary pin
●● Maximum PCB thickness
2.4 mm
●● Wave soldering profile
maximum 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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CKSR series
Dimensions CKSR Series (in mm. General linear tolerance ± 0.25 mm)
Connection
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