Looking at the data sheets for the 2N3904 and 3906 transistors.
What does "Delay" "Rise" "Storage" and "Fall" times mean? Aside from the obvious - they have to do with timing. Most curious about "Storage". (see below for my issue)
_3904 ________________ 3906_
-35 nS ---- Delay --- 35 nS
-35 nS ---- Rise ---- 35 nS
200 nS -- Storage - 225 nS
-50 nS ---- Fall ----- 75 nS
This circuit (in part) (below) is operating at 12 volts. R2 is a square wave input (high / low). The 3906 is getting warm. After a minute of operation I'm measuring a case temperature of 99˚F. This is concerning! The red line is 12 VDC (no resistance) and the black line out of the bottom of the 3906 goes direct to ground. This should only be charging and discharging an IGBT Gate.
The IGBT gate capacitance is:
Cies --- Input Capacitance --------------- 5770 -- pF VGE = 0V /// VCC = 30V
Coes -- Output Capacitance ------------- 400 --- pF
Cres -- Reverse Transfer Capacitance ---- 100 --- pF
Cut and pasted from a larger diagram. Available if necessary - but many have already seen it.
What does "Delay" "Rise" "Storage" and "Fall" times mean? Aside from the obvious - they have to do with timing. Most curious about "Storage". (see below for my issue)
_3904 ________________ 3906_
-35 nS ---- Delay --- 35 nS
-35 nS ---- Rise ---- 35 nS
200 nS -- Storage - 225 nS
-50 nS ---- Fall ----- 75 nS
This circuit (in part) (below) is operating at 12 volts. R2 is a square wave input (high / low). The 3906 is getting warm. After a minute of operation I'm measuring a case temperature of 99˚F. This is concerning! The red line is 12 VDC (no resistance) and the black line out of the bottom of the 3906 goes direct to ground. This should only be charging and discharging an IGBT Gate.
The IGBT gate capacitance is:
Cies --- Input Capacitance --------------- 5770 -- pF VGE = 0V /// VCC = 30V
Coes -- Output Capacitance ------------- 400 --- pF
Cres -- Reverse Transfer Capacitance ---- 100 --- pF
Cut and pasted from a larger diagram. Available if necessary - but many have already seen it.
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