Datasheet

17

Rev. 1.0, 2008-01-23

Smart High-Side Power Switch

BTS50080-1TMB

Protection Functions

6.3

The device can not block a current flow in reverse polarity condition. In order to minimize power dissipation, the

sufficient gate to source voltage is generated

V

Figure 14

Reverse battery protection

Additional power is dissipated by the integrated

R

dissipation

P

For reverse battery voltages up to

V

ground. This can be achieved e.g. by using a small signal diode D in parallel to the input switch or by using a small

signal MOSFET driver. For reverse battery voltages higher then

V

recommended. The overall current through

R

Note: No protection mechanism is active during reverse polarity. The IC logic is not functional.

Reverse.emf

IN

-I

L

R

bb

V

bb

R

IN

IS

R

IS

-V

bb

-I

IN

power ground

signal ground

-I

IS

I

Rbb

D

Pdiss(rev) RON(rev) IL

2

⋅

Rbb IRbb

2

⋅

+

≈

1

---------

1

--------

+

0.08A

–

-------------------------------

=