TLE7242-2G Datasheet, PDF (19/50 Pages) Infineon Technologies AG – 4 Channel Fixed Frequency Constant Current Control IC

TLE7242-2G
Functional Description and Electrical Characteristics
5.3.1 On-State Diagnostics
When the OUTx pin transitions high, the fault timers are cleared to 0 and the tested timer starts. If the tested timer
expires, the Bit SB-T (in the SPI register #9) is set to 1. If the OUTx pin transitions low, the tested timer is cleared
and then used for the off-state diagnostics.
If the analog SB fault signal (SB-FA) changes to 1, the fault filter timer starts. If the fault filter timer expires, the
digitally filtered SB fault signal (SB-FD) is set to one. If SB-FA changes to 0, SB-FD changes immediately to 0 and
the filter timer is cleared to 0.
A SB-FD=1 and SB-T=1 switches off the OUTx signal and the SB-F bit in the FAULT register will be set. The OUTx
pin remains in the off state until the fault retry PWM period counter expires.
If the SPI fault register is read, then the SB-F bit and the SB-FT bit in the FAULT register are cleared. Also, the
tested timer is cleared to 0.
The Short to Battery (SB) detection functions in both on/off and constant current mode. The SG-FD and OL-OFF-
FD signals are held to 0 while the OUTx pin is high.
If the TLE7242 2G IC is in ON/OFF mode, Open Load ON detection is disabled (OL-ON-F = 0).
If the TLE7242 2G IC is not in ON/OFF mode and the OUTx pin is high for 64 PWM periods, then open load fault
ON mode is detected and the OL-ON-F bit in the FAULT register is set. This bit will be cleared when a SPI fault
read occurs. If the OUTx pin remains in a high state, then the open load - on fault condition is detected again after
another 64 PWM cycles.
PWM_Start
OUTx
SB-T
Load
short
ok
Vpos
Vsb
SB-F
Load
Current
Tested
Timer
Fault
Filter
Fault Retry Time
(Address #8)
Tested
Timer
Fault
Filter
SPI READ
ADDR 9
Short to Vbat
Figure 12 On-State Diagnostic Timing - Short to Vbat
Data Sheet
19
Rev. 1.0, 2008-07-09