Datasheet MCC, MCD, MDC (IXYS) - 4

IXYS Thyristor/Diode Module Types M##501-12io2 to M##501-18io2 8.0 Computer Modelling Parameters
8.1 Thyristor Dissipation Calculations I AV = WAV = − VT 0 + VT 0 + 4 ⋅ ff ⋅ rT ⋅ WAV
2 ⋅ ff 2 ⋅ rT
2 2 and: ∆T
Rth ∆T = T j max − TK Where VT0 = 0.85 V, rT = 0.30 mΩ. Rth = Supplementary thermal impedance, see table below and
ff = Form factor, see table below.
Supplementary Thermal Impedance
Conduction Angle 30° 60° 90° 120° 180° 270° d.c. Square wave 0.0702 0.0685 0.0679 0.0668 0.0658 0.0637 0.0620 Sine wave 0.0677 0.0673 0.0664 0.0655 0.0650 Form Factors
Conduction Angle 30° 60° 90° 120° 180° 270° d.c. Square wave 3.464 2.449 2 1.732 1.414 1.149 1 Sine wave 3.98 2.778 2.22 1.879 1.57 8.2 Calculating thyristor VT using ABCD Coefficients
The on-state characteristic IT vs. VT, on page 6 is represented by a set of constants A, B, C, D, forming
the coefficients of the representative equation for VT in terms of IT given below: VT = A + B ⋅ ln (I T ) + C ⋅ I T + D ⋅ I T
The constants, derived by curve fitting software, are given below for both hot and cold characteristics.
The resulting values for VT agree with the true device characteristic over a current range, which is limited
to that plotted.
25°C Coefficients
A 125°C Coefficients
A 1.1481301 5.582967×10 -4 B -0.07739233 C 2.407706×10 -4 C 1.873999×10-4 D -4.020685×10-3 D 0.01475625 B 1.27624207 Rating Report. Types M##501-12io2 and M##501-18io2 Issue 2 Page 4 of 10 August, 2011