Board schematics

UM0580

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8.1

Gate driving circuit

Figure 9 shows the circuit used to turn the power MOSFETs on and off.

During the turn-on phase, the power MOSFET gate capacitances are charged through 50-

Ω

resistors while the turn-off is secured by the D3 diode (or similar).

Use of the L6390D device always guarantees a minimum adjustable dead time (DT). This

dead time is applied to the HVG and LVG outputs whenever a dead time shorter than DT is

present on the HIN and LIN inputs. The R12, R32 and R52 values being equal to 47 k

Ω,

set the minimum dead time to approximately 600 nsec.

8.2

Overcurrent protection

A hardware overcurrent protection has been implemented on the board taking advantage of

the comparator integrated inside the L6390D. The internal connection between the

comparator output and the shutdown block makes the intervention time of the overcurrent

protection extremely low, slightly above 100 nsec.

Figure 9.

Detailed gate driving circuit

AM01265v1

Figure 10.

Overcurrent protection

AM01266v1