SMT current sense transformersB82801A1EE 4.2 V B sense G max max max = -------------------- n s Ae fosc With: Bmax Maximum magnetic flux density in the ferrite core of the current sense transformer Vsense,max Maximum output voltage of the measurement signal Gmax Maximum duty cycle ns Number of turns of the secondary winding of the current sense transformer Ae Effective magnetic area of the ferrite core fosc Operating frequency of the switching operator IC Typical value for Ae: 1.44 x 10-6 m2 Typical Bmax: 200 mT V n R sense max s T = ----------------- Iprim max With: RT Resistance of burden resistor Vsense,max Maximum output voltage of the measurement signal ns Number of turns on the secondary side of the CT Iprim,max Maximum primary current (peak current) Characteristics and ordering codes Lmin Turns ratio DC resistance Voltage- Recomm. Ordering code Rmax (m:) time product RT at n 1) s PH np : ns primary secondary V μs : 33 1 : 20 2.5 700 5.76 20 B82801A1333A020 74 1 : 30 2.5 1100 8.6 30 B82801A1743A030 132 1 : 40 2.5 1500 11.5 40 B82801A1134A040 205 1 : 50 2.5 2400 14.4 50 B82801A1214A050 295 1 : 60 2.5 3600 17.3 60 B82801A1304A060 400 1 : 70 2.5 4600 20.0 70 B82801A1404A070 820 1 : 100 2.5 9000 28.8 100 B82801A1824A100 1280 1 : 125 2.5 15000 36.0 125 B82801A1135A125 1840 1 : 150 2.5 22700 43.2 150 B82801A1185A150 1) The maximum volt-sec rating limits the peak flux density to 200 mT when used in a unipolar drive application. For bi-polar drive applications, a maximum volt-sec of two times is acceptable. Please read Cautions and warnings and 5 03/20 Important notes at the end of this document.
