Electrical Sensors / Detectors / Transducers

Automotive Current Sensor operates at frequencies over 200 kHz.

PREMO Group Jun 02, 2010

Press Release Summary:

Measuring 8.5 mm high, 35 A, CS-100-AU features high-temperature-stability toroidal ferrite core that allows 200 kHz working frequencies at -40 to +155Ã‚ÂºC operating temperatures. Unit is suited for hybrid and electric vehicles and works at 400 V in input site. It guarantees 3 kV isolation and creepage distance of greater than 6.5 mm, and also has typical DCR of 0.5 mW. Primary DC resistance is 0.5 mW and secondary DC resistance is 0.8 W, with primary to secondary capacitance of less than 7 pF.

Original Press Release:

New Current Sensor for Automotive (CS-100-AU)

Premo develops Industry Smallest 35 Amp current sensor for automotive.

Max height 8.5mm with less than 2.7 cm2 PCB usage.

Inverters and DC/DC battery chargers for Electric and Hybrid Vehicles require minimum space (Premo's New Automotive Current Sensor use just 2.4mm3), and maximum power handling per cubic cm (This sensor handles 14.6A/cm3). A proper switching management require digital controls more than conventional PWM and a real time high frequency (The sensor is designed for 200kHz) sampling of the currents flowing through the primary is a must for high speed anticipative control systems.

The new CS-100-AU current sensor is designed with low losses and high temperature stability toroidal ferrite core which allows working frequencies higher than 200 kHz at operating temperatures from -40ÂºC up to 155ÂºC.

The converters for hybrid and electric vehicles works at high voltage (400V) in the input site, which makes a must to isolate primary winding of the current sensor, directly connected to the high voltage circuit, from the secondary site, connected to the control circuit. Premo current sensor guarantees 3kV isolation and a creepage distance > 6.5mm.

A precise (Premo sensor precision 2%) sensing of primary currents let the system manage line and specially load regulation being able to set the workload and optimum working point either to maximize power or to minimize power consumption or dissipation (Sensor dissipation less than 1W). Above all, a low DCR current sensor (Premo's typical DCR is 0.5mOHM), is an efficient tool for ZVT and ZVS full bridge topologies to minimize stress in High frequency switching MOFET's.

Main characteristics:

- Nominal primary current 35 Arms

- Turns ratio 1:100

- Secondary Inductance > 4mH

- Primary DC resistance = 0.5 mOhm typ

- Secondary DC resistance = 0.8 Ohm typ

- Primary to Secondary capacitance < 7pF

- Primary to Secondary Isolation > 3kVdc

- Operating temperature: -40ÂºC to 155ÂºC

Among those characteristics PREMO current sensor is fully AECQ-200C complaint and ready to use in AOI (Automatic Soldering Inspection) system, as required in automotive market.

The fast Industry Revolution that is changing the Auto sector is making design time and time to market as fast as in Consumer and ready- to- use off the shelf solutions fully qualified helps Power Electronics Design Engineers increase their throughput by standardization.

This format is also available in two extra turns ratio as per below table:



Code             Primary  Secondary Turns  Secondary   DCR Primary typ  DCR Secondary   Primary to Secondary 

                 Current                   Inductance  (mOhm) DCR       typ (Ohm)       Isolation (kVdc)

                 Irms (A)                  mH (Min)



CS-050-AU        35       50               1.0         0.5              0.25            3

CS-100-AU        35       100              4.0         0.5              0.8             3

CS-200-AU        35       200              16.0        0.5              1.6             3