High Current H-Bridge

BTM7745G

Application Information

Data Sheet

21

Rev. 1.0, 2010-05-28

It is recommended to do the freewheeling in the low side path to ensure a proper function and avoid unintended

overtemperature detection and shutdown. For proper operation it is also recommended to put a pull-down resistor

R

open load detection.

Considerations for Open Load Detection Mode

As mentioned in Chapter 6.4.1 both high side switches can be switched on independently while all other switches

are off. This will be realized by setting the corresponding IN signal to high while INH and the other IN are low.

Device State

Inputs

Outputs

Mode

INH

IN1

IN2

HS1

LS1

HS2

LS2

ST

Open-Load detection

mode

0

0

1

OFF

OFF ON

OFF

1

HS2 active

0

1

0

ON

OFF OFF

OFF

1

HS1 active

0

1

1

ON

OFF ON

OFF

1

both HSx are active

Together with the recommended pull-down resistors on the outputs OUTx to GND this provides the possibility to

do an open load detection in H-bridge configuration.

In case of one high side is active while the other half bridge is off (HS off and LS off) a current of up to 2mA will

be sourced out of the OUT of the high ohmic half bridge. This has to be considered while choosing the right value

of the pull-down resistor.