Littelfuse Sxx25x Series - Manual (Page 5)

299
Revised: 09/23/13
©2013 Littelfuse, Inc
Specifications are subject to change without notice.
Teccor ® brand Thyristors
20 / 25 Amp Standard SCRs
Sxx20x & Sxx25x Series
Figure 9: Maximum Allowable Ambient Temperature vs. Average On-State Current
0
20
40
60
80
100
120
0.0 0.5 1.0 1.5
CURRENT WAVEFORM: Sinusoidal
LOAD: Resistive or Inductive
CONDUCTION ANGLE: 180°
FREE AIR RATING
Sxx25L
Sxx25N
Sxx25R
Sxx20L
Average On-State Current [I
T(AVE)
] - Amps
Maximum Allo
w
able Ambient
Temper
at
ur
e (T
A
) - ºC
Note: xx = voltage
Figure 10: Peak Capacitor Discharge Current Figure 11: Peak Capacitor Discharge Current Derating
1000
10
100
0.5 1.0 10.0 50.0
Sxx20L
Sxx25L
Sxx25R
Sxx25N
Pulse Current Duration (t
W
) - ms
P
eak Disc
har
g
e
Cur
rent (I
TM
) -
Amps
I
TRM
t
W
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 25 50 75 100 125 150
Case Temperature (T
C
) - ºC
Nor
maliz
ed P
eak Cur
rent
10
100
1000
1 10 100 1000
Sxx25L
Sxx25R
Sxx25N
Sxx20L
P
eak Sur
g
e
(Non-r
epetitiv
e)On-stat
e
Cur
rent (I
TSM
) –
Amps
Surge Current Duration -- Full Cycles
Figure 12: Surge Peak On-State Current vs. Number of Cycles
SUPPLY FREQUENCY: 60 Hz Sinusoidal
LOAD: Resistive
RMS On-State Current: [I
T(RMS)
]: Maximum Rated
Value at Specified Case Temperature
Notes:
1. Gate control may be lost during and immediately
following surge current interval.
2. Overload may not be repeated until junction
temperature has returned to steady-state
rated value.