DocID024230 Rev 1

11/15

AN4250

Fishbone diagram

15

The above condition is better described when the intrinsic Power MOSFET R

g

is much

lower than the gate driver resistor R

d

and the Power MOSFET threshold V

th

is close to the

lower datasheet limit.

Causes linked to the method

An improper thermal dissipation due to incorrect driving/heatsink, can cause an overheating

of the device with failure.

Figure 10. Fishbone diagram

APPLICATION

FAILURE

LOSSES DURING THE

SWITCHING

STARTUP

SHORT-CIRCUIT

SWITCHING

DIODE

RECOVERY

MATERIAL

WRONG

DIMENSIONED CHOKE

SHORT-CIRCUIT

OF THE LOAD

METHOD

INADEQUATE DRIVING

INFLUENCE OF INTRINSIC

POWER MOSFET

CHARACTERISTICS (Rg, Vth,

Crss)

WRONG

HEATSINK

DIMENSIONING

AM17358v1