VNI2140J

Open load

Doc ID 15187 Rev 8

13/23

7

Open load

line and the output pin.

In a normal condition a current flows through the network made up of a pull-up resistor and

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

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

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

<