DocID022313 Rev 2

11/17

L6370Q

Circuit description

17

3.1

Diagnostic truth table

3.2

Input section

The input section is a high impedance differential stage with high common and differential

mode range. Built-in offset of +1.4 V (typical value) and a hysteresis of 400 mV (maximum

value) assure high noise immunity.

3.3

Diagnostic logic

The operating conditions of the device are permanently monitored and the following

occurrences are indicated by DIAG1/DIAG2 open drain output pins:

•

maximum current that can be sourced from the OUTPUT pin (for more details see

Section 3.4: Short-circuit operation)

•

•

Undervoltage (UV)

•

Overtemperature (OVT)

•

Open load, if the output current is less than 3 mA (typical value)

•

Output DMOS open according to Table 7

Table 7. Diagnostic truth table

Diagnostic conditions

Input

Output

Diag1

Diag2

Normal operation

L

H

L

H

H

H

H

H

L

H

L

H

H

L

H

H

L

H

H

H

L

L

H

H

(1)

(ON-DELAY pin grounded)

1.

A cold lamp filament, or a capacitive load may activate the current limiting circuit of the IPS, when the IPS

is initially turned on.

H

L

X

L

H

H

H

H

Output DMOS open

L

H

L

L

H

L

H

H

Overtemperature

L

H

L

L

H

H

L

L

L

H

L

L

L

L

L

L