AUIR08152S

12

Rev. A8.0

2015-11-09

General Application Hints

IN & LPM interface

IN and LPM have a current capability of 10mA max (source and sink); these limits only apply in case the stage

driving these signals may go above Vcc or below Vcc-40V.

In the majority of cases, when the driving stage is only an open collector, referenced at GND or

–Vee, when

looking at the functional block diagram, it appears the internal comparators have 6V zener clamp diodes, whose

reported in the static electrical characteristics for Vcc=15V and IN and LPM being pulled down at GND level.

In any case, when driving IN and LPM via open collector outputs, a pull-up resistor is needed, to guarantee

clean rise times (fall time are uniquely determined by the speed the open collectors turns-on).

Rise time is determined by the pull-up resistor and the equivalent pin capacitance to Vcc. Typically few hundred

Ohm to few kOhm are placed here.

If a push pull, and not an open collector, stage is used to drive IN and LPM, no pull-up resistor is needed but pay

attention the push pull stage is fed between Vcc and GND or Vcc and

–Vee.

A pull down resistor (few hundred kOhm) is suggested instead, especially if long traces or cables connect the

predriver to the buffer IC.

IC power dissipation

This figure is mostly related to the switching frequency, the value of external gate resistances, and the

equivalent load capacitance (the IGBT gate Ciss).

A complete characterization of the IC capabilities is given in figure 6, and shown here again for sake of clarity.