Datasheet

SPI Driver for Enhanced Relay Control
SPIDER - TLE7231G
Diagnostic Features
Datasheet 20 Rev. 1.1, 2011-04-12
8 Diagnostic Features
The SPI of TLE7231G provides diagnosis information about the device and about the load. The diagnosis
information of the protective functions of channel n is latched in the diagnosis flag Dn. The open load diagnosis of
channel n is latched in the diagnosis flag OLn. Both flags are cleared by INn =00
B
and the diagnosis current I
D(PD)
,
which is a small pull down current, is disabled.
Following table shows possible failure modes and the according protective and diagnostic action.
j
8.1 Open Load Diagnosis timing
The TLE7231G offers a open load diagnosis for each channel in OFF mode.
The time t
d(fault)
is applied to filter short time events.
Figure 9 Open Load timing
Failure Mode Comment
Open Load
or short circuit to GND
Diagnosis, when channel n is switched on:
INn = 01
B
: if input pin is high: none
INn = 10
B
: none
Diagnosis, when channel n is switched off:
INn = 00
B
: none, diagnosis flags are cleared and the diagnosis current is switched off
INn = 01
B
: if input pin is low, according to voltage at the output pin, the flag OLn is set
after time
t
d(OL)
INn = 11
B
: according to voltage level at the output pin, flags OLn are set after time t
d(OL)
Over temperature When over temperature occurs, the affected channel n is switched off. The according
diagnosis flag Dn is set.
The diagnosis flags are latched until they have been cleared by INn = 00
B
. The over
temperature detection is active in ON-state as well as OFF-state.
Over Load
(Short Circuit)
When over load is detected at channel n, the affected channel is switched off after time
t
OFF(OVL)
and the dedicated diagnosis flag Dn is set.
The diagnosis flags are latched until they have been cleared by INn = 00
B
.
OpenLoad.emf
IN
V
DS
t
t
t
d(fault)
OL
n
= 1
b
Open Load occures here
IN
V
DS
t
t
t
d(fault)
OL
n
= 1
b
V
DS(OL)
Open Load occures here
V
DS(OL)