TLE6244 datasheet(32/70 Pages) INFINEON

32 / 70 page

Final Data Sheet

V4.2, 2003-08-29

TLE 6244X

1.8 Unused Power Stages

To avoid an „open load“ fault indication an unused power switch has to be connected to an exter-

nal pull up resistor connected to UUB or has to be switched on by the input pin or via SPI or the

µsec-bus-interface.

RPull-up,max = (UBRmin - Udrop,max - UthresOL,max) / Idiag,max

UBRmin is the required minimum battery voltage for diagnostic function of the ECU. The drop volt-

age is composed of the drop voltage of the regulator and the drop voltage of the reverse protec-

tion circuit of the regulator resp. the forward voltage of a reverse protection diode.

Attention:

This equation also applies to power switches that are used as signal drivers (pull up resistor

inside ECU or outside ECU): the permissible pull up resistance without a wrong diagnostic infor-

mation is calculated by the same equation. On dimensioning the pull up resistance in combination

with the diagnostic current, in applications as signal drivers attention must be paid especially to

the required high level (also for low battery voltage).

TLE6244X

Idiag

RPull-up

UthresOL

UBR

UUB

UBatt

Voltage

OUTi

Udrop

UUBatt

regulator

TLE6244 Datasheet(PDF) 32 Page - Infineon Technologies AG