Infineon XENSIV TLI4971 - Margin Test

Application Note 19 of 31 Rev. 1.30
2022-03-01
Current Sensor TLI4971
Programming Guide and User Manual
Table 13 EEPROM voltage and timing parameter
Parameter
Symbol
Min
Typ
Max
Unit
Note
Programming Voltage
V
PROG
20.5
20.6
21.0
V
EEPROM designed to write under
specified condition on the first shot.
In case of lower voltage (i.e. 15V)
Infineon recommends a margin test
to proof quality of EEPROM content
and repeat the programming-
sequence if needed.
EEPROM threshold margin
level at start of lifetime
1)
V
TH_0h
3.55
3.8
4.15
V
“1” programmed cells
0.25
V
“0” programmed cells
EEPROM threshold margin
level after lifetime
V
TH_LT
1.9
V
“1” programmed cells
1.1
V
“0” programmed cells
Margin voltage sweep
range, test of “1” bits
V
margin
1.3
4.3
V
25mV step size recommended
Margin voltage sweep
range, test of “0” bits
0
1.7
V
EEPROM Programming time
t
EEPvprog
30
ms
Time to apply programming voltage
V
PROG
on OCD2 pin
EEPROM wait time
t
EEPwait
100
µs
Wait time after EEPROM refresh
command
Programming Current
consumption
I
PROG
6
10
mA
Current consumption of OCD2 while
applying the programming voltage
1) Limits for EEPROM programming and margin level test at the same temperature. Alternatively the temperature
characteristic of the margin level test needs to be considered: VTH(T)=VTH(WRITE_ERASE)+0.0016V/K*(TPROG-T).
Please note that only a typical temperature coefficient is used.
4.3 Margin Test
The margin test command is used in order to check the threshold voltages of the programmed EEPROM cells.
For reliable sensor EEPROM operation the threshold level of the cells have to be kept within the specification
(Table 13). After sending the margin test command an external margin voltage can be switched to the control
gates while refreshing the EEPROM-registers by an external trigger, so that the switching threshold of the
EEPROM cells can be identified (Table 13). EEPROM cells programmed to '0' or to '1' need to be tested
separately. For the '1' programmed cells a threshold voltage smaller than the applied margin voltage a '0' will
be stored to the EEPROM registers, for those with a higher threshold a '1'. Vice versa the procedure when
testing '0' programmed cells, for a margin voltage smaller than the threshold a '1' and for those higher than the