WESTCODE An IXYS Company
Fast Symmetrical Gate Turn-Off Thyristor type H0500KC25#
2.5 Gate trigger characteristics.
These are measured by slowly ramping up the gate current and monitoring the transition of anode current
and voltage (see diagram 7). Maximum and typical data of gate trigger current, for the full junction
temperature range, is given in the curves of figure 6. Only typical figures are given for gate trigger voltage,
however, the curves of figure 1 give the range of gate forward characteristics, for the full allowable
junction temperature range. The curves of figures 1 & 6 should be used in conjunction, when considering
forward gate drive circuit requirement. The gate drive requirements should always be calculated for lowest
junction temperature start-up condition.
Not to scale
Diagram 7, Gate trigger circuit and waveforms.
2.6 Turn-on characteristics
The basic circuit used for turn-on tests is given in diagram 8. The test is initiated by establishing a
circulating current in Tx, resulting in VD appearing across Cc/Lc. When the test device is fired Cc/Lc
discharges through DUT and commutates Tx off, as pulse from Cc/Lc decays the constant current source
continues to supply a fixed current to DUT. Changing value of Cc & Lc allows adjustment of ITM and di/dt
respectively, VD and i are also adjustable.
i Tx D
Diagram 8, Turn-on test circuit of FT40.
The definitions of turn-on parameters used in the characteristic data are given in diagram 9. The gate
circuit conditions IGM & IG are fully adjustable, IGM duration 10µs.
Diagram 9, Turn-on wave-diagrams.
Data Sheet. Type H0500KC25# Issue 2
Page 6 of 15