IR2113 blowing ! help needed...

[Gyula]

More tip: Let's consider the high-side SR Flip-Flop in the 2113. If the 2113's output ground is at a significantly lower potential than his input ground, the FF can switch on, and cause an unexpected situation.
But I think one of the FETs was taken for a ride by the flat supply, and it caused a chain reaction.

[Workhorse]

Originally posted by phase_accurate
Did anyone knock ??

Regards

Charles

Ahh...there we have our Charles!..... with invaluable perks for this thread
Thanks for contributing.....

Originally posted by Tim__x
They're almost never shown, but schottky protection diodes (from the IR2113's gate output to mosfet source) are often needed. Especially with very low, or zero, gate resistors.

could you draw the schematic please....A photo would say 1000 words....

regards,
K a n w a r

[Tim__x]

A photo would say 1000 words....

Quite true.

Here's what I mean, D1 protects U1 from the undershoot created by the parasitic inductance L1. Without it undershoot can forward bias the substrate, in some cases causing latchup.

[alexclaire]

here is the amp on a single side pcb
very low noise at the output when no signal

[alexclaire]

and another one...
comments are welcome ;-)

[Gyula]

What are those DO-41 diodes beside the FETs' leg? I suggest you to publish a schematic. If those are not UF rectifiers, those must be responsible for the murder. They are also pretty small for freewheeling.
I also commited to the flames a PCB three years ago. I used 1N4007 standard rectifiers for freehweeling. The supply was 100 V 50 A capable. All of the four 2113s burnt. There was about a ten centimeters tall jet of flame coming out from one of the 2113s. Half of the IC is disappeared in 2-3 seconds. The 5 mm PCB tracks between the FETs become fuses.
Your FETs have quite fast parasitic diodes, but a schematic maybe speed up the survey.

[alexclaire]

Hi,
The diodes u're talking about are anti parralel diodes over gate resistors (39 ohms) they were UF4004 but I changed them to 1N4148 advised by FREDOS (D-AMP) (4ns reverse recovery time).

Bootstrap diode was UF4004 also but not fast enough trr=50ns then replaced by MUR120 (trr=25ns) maybe the reason why it failed...

I also add 10kohms // 15V zener between gate and source of each fet in order to protect them from destructive voltages spikes...

I'm gonna try this tomorrow...

[Gyula]

The 1N4148 is a 300 mA switch diode. It may be sufficient for simple bipolar FET controllers, but not for a 2.5 A peak output current capable driver. There is a chart and a diagram on the picture above. There you can see when the driver is switching to low, not the output resistance, but the weak diode will limit the discharging current. Then the diode's body absorbing some watts of power because of the high forvard voltage. You can see the thermal resistance in the chart (300 K/W). You can calculate the average dissipated power by the ratio of discharging and the total time. But as the body temperature rises, the chance for a thermal breakdown is getting bigger, because of the power spikes at discharging (the temperature is fluctuating at the junction).
The Non-Repetitive Peak Forward Current is Non-repetitive. This is the amount of energy the diode can absorb once started from 25C with no overheating.
There are some Schottkies with amperes forward current range, and without recovery effect, because they haven't p-n junction.
A schematic would give some help.

[fredos]

Hello Gyula

Just remember that discharge of a mosfet is done in less than a ns....With 2A peak output power of the IR2113, there is no probleme to discharge a mosfet gate with a 1N4150! As you say, read chart!

Fredos

[fredos]

Hi just check your board....Where is the decoupling cap between V+/V- at mosfet junction? Could be very helpfull to avoid ringing....And mosfet destruction!

Fredos

www.d-amp.com