MnZn Power Ferrite · Mid-frequency power · Material specification

TM80

WIDE-TEMPERATURE LOW-LOSS POWER FERRITE

SMPS Main TransformerForward / Flyback TransformerAutomotive PowerWide-Temperature Supply

TM80 is a wide-temperature low-loss MnZn power ferrite with an initial permeability (μi) of 3000, a saturation flux density (Bs) of 520 mT at 25 °C (420 mT at 100 °C) and a Curie temperature above 230 °C. Its core loss is nearly constant between 25 °C and 100 °C (100 kHz / 200 mT: 350 → 330 kW/m³; 500 kHz / 50 mT: 200 → 200 kW/m³), without the behaviour of conventional power grades whose loss is elevated at room temperature and reaches its minimum only when warm; efficiency at cold start and at full-load steady state is therefore equally predictable. With 420 mT of Bs and a coercivity of 7 A/m at 100 °C, transformers retain their saturation margin at large flux swings. Typical applications are 100–300 kHz switch-mode main transformers and forward/flyback transformers, particularly automotive, outdoor and industrial supplies exposed to wide ambient variation. Among the six mid-frequency grades TM80 is the reference of the wide-temperature series for the 100 kHz high-flux region (the three TP grades are of the room-temperature-high, hot-state-low type): TM81 is recommended for operating points around 300 kHz / 100 mT and TM83 where the core remains at 120–140 °C for extended periods.

Magnetic Characteristics

Characteristic	Condition	25 ℃	100 ℃	Unit
Initial Permeability μiInitial Permeability μi	100 kHz & <0.2 mT	3000±25%	—	—
Amplitude Permeability μaAmplitude Permeability μa	25 kHz/400 mT	> 4000	> 4000	—
Saturation Flux Density BsSaturation Flux Density Bs	1200 A/m 100 Hz	520	420	mT
Remanence BrRemanence Br	1200 A/m 100 Hz	80	60	mT
Coercivity HcCoercivity Hc	1200 A/m 100 Hz	10	7	A/m
Loss FactorLoss Factor	100 kHz & <0.2 mT	<6	—	10⁻⁶
Curie Temperature TcCurie Temperature Tc	100 kHz & <0.2 mT	>230	—	℃
Density DDensity D	Archimedes method	>4.8	—	g/cm³
Electrical Resistivity ρElectrical Resistivity ρ	DC Current	>5.5	—	Ω·m

Power Loss · kW/m³

Condition	25 ℃	100 ℃
100 kHz/200 mT	350	330
300 kHz/100 mT	380	360
500 kHz/50 mT	200	200

Pcv = K·f^α·B^β

Range	K	α	β
100 ≤200	1.09E-07	1.7553	2.63056
100 ≤500	4.03E-07	1.71695	2.40254

Characteristic curves

CURVE 01

CURVE 02

CURVE 03

CURVE 04

CURVE 05

CURVE 06

Applications

Application	Role	Band	Temperature
Flyback transformer (>150 W)	First choice	≤0.3 MHz	25–100 ℃
Flyback transformer (≤150 W, by IDC)	Alternative	≤0.3 MHz	—
Forward transformer	First choice	≤0.3 MHz	25–100 ℃
Push-pull transformer	First choice	≤0.3 MHz	25–100 ℃
LLC / resonant & bridge transformer (incl. Lr)	First choice	≤0.3 MHz	25–100 ℃
Wide- / high-temperature power transformer (core to 140 ℃)	First choice	≤0.3 MHz	25–100 ℃
Buck output inductor	Alternative	≤0.3 MHz	—
Boost input inductor	Alternative	≤0.3 MHz	—
PFC chokes & high-current storage inductors	Alternative	≤0.3 MHz	—
Forward / push-pull output inductor	Alternative	≤0.3 MHz	—
VRM / TLVR / PoL inductor	Alternative	≤0.3 MHz	—

Used in circuits

AlternativeBuck converter — output inductor · Buck ≦0.3 MHz AlternativeBuck converter — output inductor · VRM／TLVR ≦0.3 MHz AlternativeBoost converter — input inductor · ≦0.3 MHz AlternativeBoost PFC — PFC choke · ≦0.3 MHz AlternativeFlyback converter — energy-storage transformer · ≦150 W ≦0.3 MHz First choiceFlyback converter — energy-storage transformer · >150 W ≦0.3 MHz First choiceForward converter — transformer & output inductor · Transformer ≤0.3 MHz AlternativeForward converter — transformer & output inductor · Output inductor ≤0.3 MHz First choicePush-pull converter — centre-tapped transformer · Transformer ≤0.3 MHz AlternativePush-pull converter — centre-tapped transformer · Output inductor ≤0.3 MHz First choiceHalf-bridge LLC — transformer & resonant inductor · ≦0.3 MHz