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Current Transducer CTSR series IPRN = 300, 600 mA
Ref: CTSR 0.3-P, CTSR 0.6-P
For the electronic measurement of current: DC, AC, pulsed..., with galvanic isolation
between the primary and the secondary circuit.
Features
● Closed loop (compensated) current transducer
● Voltage output
● Single supply voltage
● Isolated plastic case material recognized
according to UL 94-V0
● PCB mounting.
Advantages
●High accuracy
● Very low offset drift over temperature
● Wide aperture (20.1 mm)
● High overload capability
● High isolation capability
● Reference pin with two modes, Ref In and Ref Out
● Degauss and test functions.
Applications
● Residual current measurement
● Leakage current measurement in transformerless PV
inverters
● First human contact protection of PV arrays
● Failure detection in power sources
● Symmetrical fault detection (e.g. after motor inverter)
●Leakage current detection in stacked DC sources
● Single phase or three phase nominal current measurement
up to ± 30 A per wire (DC or AC).
Standards
●EN 50178
● IEC 61010-1 (safety).
Application Domain
● Industrial
● Suitable to full VDE 0126-1-1 and UL 1741.
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CTSR 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
Environmental and mechanical characteristics
Parameter Symbol Unit Value
Supply voltage VCV 7
Primary conductor temperature °C 110
Impulse overload (100 µs, 500 A/µs) A3300
Parameter Symbol Unit Value Comment
RMS voltage for AC isolation test 50/60Hz/1 min VdkV 5.4
Impulse withstand voltage 1.2/50 µs VwkV 10.1
Partial discharge extinction voltage @ 10 pC (rms) VekV 1.65
Clearance distance (pri. - sec.) dCI mm 11 Shortest distance through
air
Creepage distance (pri. - sec.) dCp mm 11 Shortest path along device
body
Comparative tracking index CTI V600
Application example -1000 V
CAT III PD2
Basic isolation, non uniform
eld according to
EN 50178
Application example -600 V
CAT III PD3
Basic isolation, non uniform
eld according to
EN 50178, IEC 61010
According to UL 508: primary potential involved in
Volt rms AC or DC - V 600 For use in a pollution
degree 3 environment
Primary conductor shall be connected after an overvoltage device or system evaluated by standard UL 1449.
Parameter Symbol Unit Min Typ Max Comment
Ambient operating temperature TA°C -40 105
Ambient storage temperature TS°C -50 105
Mass mg28
Standards EN 50178, IEC 61010-1, UL 508
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CTSR series
Electrical data CTSR 0.3-P
At TA = 25°C, VC = + 5 V, output voltage referred to VREF unless otherwise noted.
Notes: 1) See “Application information” section.
2) Only with a primary nominal residual current, see paragraph “Primary nominal residual current and primary nominal
curent”.
3) Accuracy @ TA and IP: XTA = (X2 + (TCG•100•(TA - 25))2 + (TCVOE•2.5•(TA - 25 )/Gth•100/ IP )2)1/2
Parameter Symbol Unit Min Typ Max Comment
Primary nominal residual current rms IPRN mA 300
Primary residual current, measuring range IPRM mA -500 500
Supply voltage VCV4.75 55.25
Current consumption ICmA 16 17.5 21.6
+ IP (mA)/NS
With NS = 1000 turns
- 40°C .. 105°C
Reference voltage @ IP = 0 VREF V2.495 2.5 2.505 Internal reference
External reference voltage
VREF V2.3 4
Internal resistance of
VREF input = 499 Ω
Note 1
Electrical offset current referred to primary
(Note 2)
IOE mA -24 +7 24
Temperature coefcient of VOE
@ IP = 0 TCVOE ppm/K 50 570 ppm/K of 2.5 V
- 40°C .. 105°C
Theoretical sensitivity Gth V/A 4
Sensitivity error (Note 2) εG%-1.6 0.5 1.6 RL > 500 kΩ
Temperature coefcient of GTCG ppm/K
±230 - 40°C .. 85°C
±400 - 40°C .. 105°C
Linearity error εL% of IPRM 0.5 1
Reaction time @ 10 % of IPRN tra µs 7RL > 500 kΩ,
di/dt > 5 A/µs
Response time @ 90 % of IPRN trµs 50 RL > 500 kΩ,
di/dt > 5 A/µs
Frequency bandwidth (- 1 dB) BW kHz 3.5 RL > 500 kΩ
Output voltage noise
(1 Hz .. 10 kHz) Vno mV rms 6RL > 500 kΩ
Magnetic offset current referred to
primary (1000 x IPRN)IOM mA 17
Accuracy (Note 3) X% 1.9 = (εG
2+ εL
2)1/2
Output voltage referred to GND
(during Degauss cycle) V0.3 0.5 Note 1
Output voltage referred to VREF (Test current) V0.7 1.2 1.7 Note 1
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CTSR series
Typical performance characteristics CTSR 0.3-P
Figure 1: Frequency response
Figure 2: Output noise, spectral density Figure 3: Output noise, cumulated rms
Figure 4: Typical step response Figure 5: Typical step response
Relative sensitivity (dB)
Phase (°)
Frequency (Hz)
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CTSR series
Electrical data CTSR 0.6-P
At TA = 25°C, VC = + 5 V, output voltage referred to VREF unless otherwise noted.
Notes: 1) See “Application information” section.
2) Only with a primary nominal residual current, see paragraph “Primary nominal residual current and primary nominal
curent”.
3) Accuracy @ TA and IP: XTA = (X2 + (TCG•100•(TA - 25))2 + (TCVOE•2.5•(TA - 25 )/Gth•100/ IP )2)1/2
Parameter Symbol Unit Min Typ Max Comment
Primary nominal residual current rms IPRN mA 600
Primary residual current, measuring range IPRM mA -850 850
Supply voltage VCV4.75 55.25
Current consumption ICmA 16 17.5 21.6
+ IP (mA)/NS
With NS = 1000 turns
- 40°C .. 105°C
Reference voltage @ IP = 0 VREF V2.495 2.5 2.505 Internal reference
External reference voltage
VREF V2.3 4
Internal resistance of
VREF input = 499 Ω
Note 1
Electrical offset current referred to primary
(Note 2) IOE mA -24 4.2 24
Temperature coefcient of VOE
@ IP = 0 TCVOE ppm/K 60 520 ppm/K of 2.5 V
- 40°C .. 105°C
Theoretical sensitivity Gth V/A 2.476
Sensitivity error (Note 2) εG%-0.2 0.3 0.7 RL > 500 kΩ
Temperature coefcient of GTCG ppm/K 100 - 40°C .. 105°C
Linearity error εL% of IPRM 0.4 1.3
Reaction time @ 10 % of IPRN tra µs 5RL > 500 kΩ,
di/dt > 5 A/µs
Response time @ 90 % of IPRN trµs 30 RL > 500 kΩ,
di/dt > 5 A/µs
Frequency bandwidth (- 1 dB) BW kHz 9.5 RL > 500 kΩ
Output voltage noise
(1 Hz .. 10 kHz) Vno mV rms 4RL > 500 kΩ
Magnetic offset current referred to
primary (1000 x IPRN)IOM mA 17
Accuracy (Note 3) X%1.5 = (εG
2+ εL
2)1/2
Output voltage referred to GND
(during Degauss cycle) V0.3 0.5 Note 1
Output voltage referred to VREF (Test current) V0.4 0.75 1.1 Note 1
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CTSR series
Typical performance characteristics CTSR 0.6-P
Figure 6: Frequency response
Figure 7: Output noise, spectral density Figure 8: Output noise, cumulated rms
Figure 9: Typical step response Figure 10: Typical step response
Frequency (Hz)
Phase (°)
Relative sensitivity (dB)
10
0
10
1
10
2
10
3
10
4
10
5
-110
-105
-100
-95
-90
-85
-80
-75
-70
-65
-60
f (Hz)
v
n
(dBVrms/rtHz)
Noise voltage spectral density of V
M
Device: CTSR 0.6-P #05-61
100101102103104105
10-6
10-5
10-4
10-3
10-2
10-1
f
c
(Hz)
V
n
(V)
Cumulated RMS noise voltage of V
M
Device: CTSR 0.6-P #05-61
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CTSR series
Application information
Filtering, decoupling CTSR transducer
Supply voltage Vc (5 V):
The CTSR transducers have internal decoupling capacitors, but in the case of a power supply track on the application PCB
having a high impedance, it is advised to provide local decoupling, 100 nF or more, located close to the transducer.
Reference Vref:
Ripple present on the Vref pin can be ltered with a low value of capacitance because of the internal 499 ohm series resistance.
The CTSR transducers have an internal capacitor of 22 nF between Vref pin and Gnd pin and the maximum lter capacitance
value which could be added is 1 µF. Adding a larger decoupling capacitor will increase the activation delay of degauss.
Output Vout:
The CTSR transducers have an internal low pass lter 470 ohm/22 nF; if a decoupling capacitor is added on Vout pin, the
bandwidth and the response time will be affected. In case of short circuit, the transducer CTSR can source or sink up to a
maximum of 10 mA on its output Vout.
Using an external reference voltage
If the Vref pin of the transducer is not used it could be either left unconnected or ltered according to the previous paragraph
“Reference Vref”.
The Vref pin has two modes Ref Out and Ref In:
• 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 Vref pin of the transducer through a 499 ohms resistor. It
tolerates sink or source currents up to ±5 mA, but the 499 ohms resistor prevents this current to exceed these limits.
• In the Ref In mode, an external reference voltage is connected to the Vref pin; this voltage is specied in the range 2.3
to 4 V and is directly used by the transducer as the reference point for measurements. The external reference voltage
Vref must be able:
o either to source a typical current of , the maximum value will be 3 mA when Vref = 4 V.
o or to sink a typical current of , the maximum value will be 0.4 mA when Vref = 2.3 V.
The following graphs show how the measuring range of the transducer depends on the external reference voltage value Vref
(Vc = 5 V).
Upper limit: IP=500 mA (Vref = 2.3..2.625 V) Upper limit: IP=850 mA (Vref = 2.3..2.52V)
Upper limit: IP=-250*Vref+1156.25 (Vref = 2.625..4 V) Upper limit: IP=-403.88*Vref+1867.93 (Vref = 2.52..4 V)
Lower limit: IP=-250*Vref+93.75 (Vref = 2.3..2.375 V) Lower limit: IP=-403.88*Vref+151.45 (Vref = 2.3..2.48 V)
Lower limit: IP=-500 mA (Vref = 2.375..4 V) Lower limit: IP=-850 mA (Vref = 2.48..4 V)
499
5.2
Vref
−
499
5.2−Vref
-600
-400
-200
0
200
400
600
234
I PRM (mA)
VREF (V)
IPRM 500 mA
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
234
I PRM (mA)
VREF (V)
IPRM 850 mA
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CTSR series
Primary nominal residual current and primary nominal current
The primary nominal residual current is the sum of the instantaneous values of all currents owing through the aperture of the
transducer.
The primary nominal current is the current owing through any conductor placed into the aperture of the transducer.
The presence of a primary nominal current DC or AC leads to an additional uncertainty.
For example, with a primary nominal current of 30 A the uncertainty referred to primary is typical 4.3 mA.
CTSR transducer in Test mode
When the Vref pin is forced at a Low level voltage between 0 and 1 V and is maintained at this level, the output voltage Vout of
CTSR transducer exhibits a xed value (see specication) as if it measured a primary test current.
The activation time of test mode is min 30 ms. The CTSR transducer can be maintained in test mode as long as needed for
checking that it is fully operating.
CTSR transducer in Degauss mode
The CTSR transducers go in degauss mode automatically at each power on or on demand by using the Vref pin.
At power on:
A degauss is automatically generated at each power on of the CTSR transducer; during degaussing the output voltage Vout is
maintained at 0.3 V typ. (max 0.5 V). After c.a. 110 ms, the output voltage Vout is released and takes the normal operation level
in relation with the measured primary current.
Using Vref pin:
When the pin Vref is released from the Low level voltage dened in the Test mode above, there is a rising edge on Vref which
generates an automatic degauss.
The activation of degauss takes typically 40 µs after releasing Vref pin, then degauss lasts typically 110 ms.
Isolation around the CTSR transducer housing
Due to the joint between the case and the cover of the CTSR transducer, there is some isolation distance to respect when
primary conductors pass around the CTSR housing.
The gure below shows the joint and the apertures where the clearance between the secondary part inside the CTSR
transducer and the surface of the housing is 3 mm (label E).
Vref
Vout referred to Vref
1 V
30 msMeasured Ipr
Measured Ipr
0.7 V
1.7 V
110 ms
-2 V
Test mode Degauss mode
-2.5 V
Summary of test and degauss modes at Vref = 2.5 V
2.5 V
Measuring Measuring
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CTSR series
PCB Footprint CTSR series
Assembly on PCB
• Recommended PCB hole diameter 1.2 mm for secondary pin
2 mm for retention pin
• Maximum PCB thickness 2.4 mm
• Wave soldering prole maximum 260 °C, 10 s
No clean process only
The two retention pins inserted into the case of the transducer are electrically isolated by the housing. Because one of them is
close to the secondary connector, it is recommended to connect both to the secondary side GND or +Vc.
Consequently any primary conductor must be placed in the PCB at the requested isolation distance regarding these secondary
sides (see also paragraph “Isolation around the CTSR transducer housing”).
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 (e.g. primary bus bar, 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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CTSR series
Dimensions CTSR series (in mm, general tolerance ± 0.3 mm)
Connection