[SOLVED] Does TLE9879 power sequence meet LV124 automotive test standard ?


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Level 1
Level 1

I am currently testing the power-up sequence. This is "spite" test for TLE9879. This test should succeed in order to pass LV124 automotive test standard.
Power-up sequence test mean, they change dv/dt, like (from 0v to 12v)/20mS, (from 0v to 12v)/21mS, (from 0 to 12v)/22mS, and so on.
The TLE9879 should accept/meet (from 0v to 12v)/500mS for passing LV124 automotive test standard.

Following N.G mean, their LIN communication mode are started as "LIN Receive Only Mode".
Following O.K mean, their LIN communication mode are started as "LIN Normal Mode".
When dv/dt = (from 0v to 12v)/22mS and more than (from 0v to 12v)/22mS, like (from 0v to 12v)/23mS, then NG.
When dv/dt = (from 0v to 12v)/21mS and less than (from 0v to 12v)/21mS, like (from 0v to 12v)/20mS, then O.K.

It seems that TLE9879 LIN communication is O.K, when VS rise time are fast.
While TLE9879 LIN communication is N.G when VS rise time are slow over 22mS from 0v to 12v.


My questions:
Q1. Does TLE9879 meet "LV124 automotive test standard"?
Q2. (If Q1. is yes) do you think TLE9879 should be O.K. even if VS rise time is more than 22mS from 0v to 12v?
1 Reply
Answer 1: Yes the TLE9879 is tested according to LV124.

Answer 2: In the car, we expect every possible voltage slope and transistion. Even slower slopes should not have an influence on the functionality.
If the customer detects that the LIN transceiver is in receive only mode, he can reconfigure the module to normal mode.

There is a hint in the Users Manual Page 651:
LIN Normal Mode (LNM) - LIN Receive-Only Mode (LROM) Transition Description
• LNM - LROM transition is executed when
MODE is configured to LIN Receive-Only Mode or
Feedback signals of Mode and Slope Mode are not ok or
VS undervoltage flag (VS_UV_STS) is set or
LIN transceiver OT_STS or OC_STS are set or
TXD_TMOUT is set

In case the the voltage slope is very slow, an VS undervoltage can be triggered, which causes the LIN to go in Receive-only mode.