Datasheet

VNI2140J Open load
Doc ID 15187 Rev 8 13/23
7 Open load
In order to detect the open load fault a pull-up resistor must be connected between the V
CC
line and the output pin.
In a normal condition a current flows through the network made up of a pull-up resistor and
a load. The voltage across the load is less than V
OLMIN
; so the diag pin is kept high.
This is the result in the condition:
Equation 1
or
Equation 2
When a open load event occurs the voltage on the output pin rises to a value higher than
V
OLMAX
(depending on the pull-up resistor). The diag pin will go down.
This result in the condition:
Equation 3
Figure 8. Open load detection
V
CC
R
LOAD
R
LOAD
R
PU
+
----------------------------------- -
V
OLMIN
<
V
CC
V
OLMIN
-------------------- 1–
⎝⎠
⎛⎞
R
LOAD
⋅ R
PU
<
R
PU
V
CC
V
OLMAX
–
I
OUT OFF1()MIN
----------------------------------------- -
<