Epcos Ferrite Cores

EPCOS Group of TDK Corporation, maintains the Epcos identity for the ferrite manufacturing facilities.

The ferrite materials are classified in five (5) major groups as indicated below.

Power

Transformer (low loss)
f<100 kHz

  • N27 (µi = 2000) low cost, hi-power
  • N41 (µi = 2800) current transformer

f<500 kHz

  • N87 (µi = 2200) standard
  • N97 (µi = 2300) lowest losses
  • N95 (µi = 2000) flat temperature behavior
  • N51 (µi = 3000) loss min. @ 40°C

f>500 kHz

  • N49 (µi = 1500)
Output choke (high Bsat @ 100°C)

  • N87 (µi = 2200) standard
  • N92 (µi = 1500) higher saturation

Ballast

  • N72 (µi = 2500) low Br , near flat temperature behavior

Broadband

Signal transformer (low THD)
ADSL

  • T38 (µi = 10000) standard
  • T66 (µi = 13000) ADSL2

SHDSL

  • T57 (µi = 4000)
VDSL

  • M33 (µi = 750)

Splitter (high Bsat @room temperature)

  • N45 (µi = 3800)

Resonance circuit

Filter coil (low tan d/µi, high Q, stable µi over T)
f<1 MHz

  • M33 (µi = 750)

f>1 MHz

  • K1 (µi = 80)
f<100 kHz

  • N48: (µi = 2300) stable impedance over temperature
  • N45: (µi = 3800) high Bsat

Proximity switch

Sensor coil (high and stable Q over T)
f<100 kHz

  • N22: (µi = 2300)

f<1 MHz

  • M33 (µi = 750)
f>1 MHz

  • K1 (µi = 80)

EMI

Current-compensated choke (high impedance)

  • N30: (µi = 4300 ) extended frequency response
  • T35: (µi = 6000 ) medium permeability
  • T36: (µi = 7000 ) stable impedance over temperature
  • T37: (µi = 6500 ) low tanδ/µi
  • T38: (µi = 10000 ) high Inductance low ηB
  • T65: (µi = 5200 ) high Bsat and high Tc
  • T46: (µi = 15000 ) highest permeability
Filter choke (high impedance)

  • T36: (µi = 7000 ) stable impedance over temperature
  • T65: (µi = 5200 ) high Bsat and highTc

Data line choke (high data rate)

  • K10: (µi = 800 ) highest frequency

Preferred Power Material for New Designs

Manf Mat’l Initial
Perm		 Optimum
Frequency		 Flux
βsat		 Core Loss
Pcv		 Curie
Temp
KHz mT °C KW/M3 °C Conditions Tc °C
EPCOS N87 2200 25< f<300 490 25 650 25 100 KHz, 200mT 210
500 50
400 80
375 100
390 100 460 120
540 100
EPCOS N88 1800 25< f<500 500 25 750 25 100 KHz, 200mT 240
580 50
460 80
450 100
400 100 400 120
420 100
EPCOS N97 2300 25< f<500 510 25 25 100 KHz, 200mT 230
480 60 60
80
410 100 300 100
390 120 120
EPCOS N95 3000 25< f<500 525 25 460 25 100 KHz, 200mT 220
420 50
390 80
410 100 390 100
420 120
EPCOS N96 2900 25< f<500 490 25 325 25 100 KHz, 200mT 240
330 50
350 80
390 100 410 100
450 120

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