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RAZV-2 Transducer for low current measurements

When low (under 1A) currents are to be measured multiple turns are applied to the flux trapping ferrite. (See "the concept of Turns" in "What is a current transducer?"). As the maximum current to be measured decreases, so turns must increase. The RAZV-2 series provides a flux trapping ferrite pre-wound with extra turns (wound either directly onto the ferrite or onto a plastic bobbin) which allow for currents as low as a few milliamps to be measured. For the plastic bobbin parts, a standardized pin-out is provided over a wide range of turns. As well as the standard choice of five different turns-counts, Raztec can provide custom turns counts to maximize accuracy in your specific application.

Raztec Hall sensing versus resistive sensing solutions

As with other Raztec transducers, high galvanic isolation is maintained. For applications that don't require galvanic isolation, there may still be benefits in using the RAZV-2. For example the RAZV060-2 has a resistance of only 2 milliohms. At its maximum recommended current of 10A, power loss is just 0.2W. Resistors used for the same current level would typically be 10 milliohms, with 1W of power being lost, and resulting temperature rise to surrounding components. Also, the resistor ("shunt") solution provides just a 0.1 volt signal, but the RAZV060-2 provides about 1 volt - much more suitable for a microcontroller ADC.

Absolute Maximum Ratings

Parameter Symbol Value Unit
Operating Temperature TA -40 to +125 °C
Storage Temperature Tstg -65 to +150 °C
Supply Voltage Vs 8 V
Output Sinking Current Io 10 mA
Measured Current Im Limited only by conductor A

Characteristics

(TA = 25°C unless stated, VS = 5V)

Parameter Symbol Lower Limit Typical Upper Limit Unit
Supply Current (no load) Is     111 mA
Supply Voltage Vs 4.5 5.0 6.0 V
Current Range for < ±1% non-linearity (-25 to +90°C) Im ±60     AT
Power-on settling time to 99% tpo     15 µs
Null Output Voltage Vo 2.4 2.5 2.6 V
Turns - RAZV060-2    +/-10A T 6 6 6  
Turns - RAZV120-2    +/-5A T 12 12 12  
Turns - RAZV600-2    +/-1A T 59 60 61  
Turns - RAZV301-2    +/-200mA T 295 300 305  
Turns - RAZV152-2    +/-40mA T 1480 1500 1520  
Transfer Function RAZV060-2 ΔV/I 78 102 132 mV/A
Transfer Function RAZV120-2 ΔV/I 156 204 264 mV/A
Transfer Function RAZV600-2 ΔV/I 767 1020 1342 mV/A
Transfer Function RAZV301-2 ΔV/I 3835 5100 6700 mV/A
Transfer Function RAZV152-2 ΔV/I 19,200 25,500 33,450 mV/A
Approx. Resistance RAZV060-2     0.002   Ω
Approx. Resistance RAZV120-2     0.01   Ω
Approx. Resistance RAZV600-2     0.16   Ω
Approx. Resistance RAZV301-2     4   Ω
Approx. Resistance RAZV152-2     120   Ω
Non-linearity (±50AT, -25 to +90°C)       1.0 %
Hysteresis (±50AT)       0.5 %
Null drift due to temperature change TCΔVo/Vo     ±0.25 mV/K
Gain Change due to temperature change TCG -0.1 0.1 0.18 %/K
Risetime 0 to 20AT tr     14 µs
Frequency Response f-3dB   35   kHz
Output Resistance R0   2 5 Ω

*   Tighter specification units available on request.

Technical Drawing

Datasheets

Performance Characteristics







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