8

Design guidelines

8.1

Output series resistance

The output resistance allows the high frequency operation without exceeding the maximum power dissipation of

the driver package. See Section 8.2 Power dissipation to understand how the output resistance value is

obtained. For applications with VCC supply voltage greater than 10 V and high capacitive loads (Cg > 10 nF), the

dissipated power in the output stage of the device has to be limited, therefore at least 2.2 Ω Rg gate resistor has

to be added. Figure 7. Minimum gate resistance is a synthetic view of the boundaries for the safe operation of the

RHRPM4423.

10

18

VCC [V]

10

GIPD180120161238MT

8.2

Power dissipation

The RHRPM4423 embeds two high current low-side drivers which drive high capacitive MOSFETs. This section

estimates the power dissipated inside the device in normal applications. Two main terms contribute to the device

power dissipation: bias power and driver power.

•

PDC bias power depends on the static consumption of the device through the supply pins and it is given by

below equation:

Equation 1

•

The driver power is the necessary power to continuously switch on and off the external MOSFETs; it is a

dissipated power is given by three main factors:

–

external gate resistance (when present)

–

intrinsic MOSFET resistance

–

intrinsic driver resistance

RHRPM4423

Design guidelines

DS11827 - Rev 3

page 12/31