TLD1326EL_15 Datasheet, PDF (23/34 Pages) Infineon Technologies AG – 3 Channel High Side Current Source

TLD1326EL
9
Load Diagnosis
Load Diagnosis
9.1
N-1 Detection
The N-1 diagnosis is specially designed to detect error conditions in LED arrays with multiple LED chains used for
one light function. If one LED within one chain fails in open condition the respective LED chain is off. Different
automotive applications require a complete deactivation of a light function, if the desired brightness of the function
(LED array) can not be achieved due to an internal error condition. Such a deactivation feature is integrated in the
LITIX^TM Basic IC.
The functionality of the N-1 pin is shown in the following block diagram:
N-1
I_N-1
V_N-1
Output Control
Figure 17 Block Diagram N-1 pin
In applications, where more than one LITIX^TM Basic IC is used, the IN_SET pins can be connected via the PWMI
pins as shown in Figure 20 and Figure 21. This circuit can be used to disable all output stages (of all LITIX^TM
Basic ICs) during an open load event on one channel. The outputs are deactivated after a N-1 filter time t_N-1, which
is defined by the charging current I_N-1 (Pos. 9.3.6). The time is adjustable with a capacitor connected to the N-1
pin according the following equation:
t_typ
=
C_{-----N----–---1----}⋅_--V_{-----N----–---1--(--t--h--)}
I_{N – 1}
(11)
Data Sheet
23
Rev. 1.1, 2015-03-24