ATA6613 ATMEL Corporation, ATA6613 Datasheet - Page 19

• Manufacturer Part Number: ATA6613
• Description: Ata6613
• Manufacturer: ATMEL Corporation

3.3.24.2
9111C–AUTO–02/08
Worst Case Calculation with R
The internal oscillator has a tolerance of 20%. This means that t
The worst case calculation for the watchdog period t
The ideal watchdog time t
t
t
t
t
t
t
A microcontroller with an oscillator tolerance of ±15% is sufficient to supply the trigger inputs
correctly.
Table 3-2.
2
1,min
2,min
wdmax
wdmin
wd
.
R
= 29.3 ms ±4.5 ms (±15%)
WD_OSC
120
k
34
51
91
= 0.8
= 0.8
= t
= t
1max
1min
+ t
= 24.8 ms
t
Oscillator
t
1
2
Typical Watchdog Timings
Period
t
= 16.5 ms, t
= 17.3 ms, t
19.61
33.54
42.84
2min
osc
13.3
WO_OSC
/µs
= 16.5 ms + 17.3 ms = 33.8 ms
= 51 k
264.80
338.22
t
154.8
wd
Lead
Time
d
1,max
105
2,max
/ms
is between the maximum t
= 1.2
= 1.2
Window
Closed
t
20.64
35.32
45.11
14.0
1
/ms
t
t
1
2
= 24.8 ms
= 26 ms
Open Window
21.67
37.06
47.34
t
14.7
wd
2
/ms
is calculated as follows.
1
and the minimum t
ATA6612/ATA6613
Trigger Period from
1
Microcontroller
and t
t
29.32
50.14
64.05
wd
19.9
2
/ms
can also vary by 20%.
1
plus the minimum
Reset Time
t
nres
4
4
4
4
/ms
19