TLE6711_07 Datasheet, PDF (9/25 Pages) Infineon Technologies AG – Multifunctional Voltage Regulator and Watchdog

TLE 6711
Circuit Description
is HIGH the system enable goes active HIGH with the first valid watchdog trigger pulse at pin WDI. The SEN output
goes LOW immediately if a pretrigger, a missing trigger or a power down reset occurs.
T_WD = 128*t_CYL
t_SR = 64*t_CYL
t_WDR = 64*t_CYL
t_CW=32*t_CYL
t_OW=32*t_CYL
definition
closed window
open window
definition
worst case
reset start delay time after window
watchdog timeout
reset duration time after window
watchdog time-out
t_ECW
t _EOW = end of open window
f_OSC=f_OSCmax
t _(CW+OW)min = ( t_CW+ t_OW ) (1 - ∆)
f_OSC=f_OSCmin
t _CWmax= t_CW (1+∆ )
t _WD
t _OWmin
Figure 5 Window Watchdog Definitions 1
Example with:
t_CYL=1ms
∆=10% (oscillator deviation)
t_(CW+OW)min =(t_CW+t_OW)*(1-∆)=
=(32+32)x0,9= 57,6ms
t_CWmax= t_CW(1+∆)=32*1,1=35,2ms
Closed window Open window
Watchdog
trigger signal
Open window Closed window
WDI
Valid
WDI
Indifferent
WDI
Not valid
t _ECW
= Watchdog decoder sample point
t _EOW
AET02952
Figure 6 Window Watchdog Definitions 2
Data Sheet
9
Rev. 3.4, 2007-08-16