ATA6621N-PGPW Atmel, ATA6621N-PGPW Datasheet - Page 14
![TXRX LIN 5V REG WATCHDOG 20-QFN](/photos/6/87/68751/313-20-qfn_sml.jpg)
ATA6621N-PGPW
Manufacturer Part Number
ATA6621N-PGPW
Description
TXRX LIN 5V REG WATCHDOG 20-QFN
Manufacturer
Atmel
Type
Transceiverr
Datasheet
1.ATA6621N-PGPW.pdf
(28 pages)
Specifications of ATA6621N-PGPW
Number Of Drivers/receivers
1/1
Protocol
LIN
Voltage - Supply
5 V ~ 18 V
Mounting Type
Surface Mount
Package / Case
20-QFN Exposed Pad
Number Of Transmitters
1
Number Of Receivers
1
Power Supply Requirement
Single
Package Type
QFN EP
Operating Temperature Classification
Automotive
Mounting
Surface Mount
Pin Count
20
Operating Temperature (max)
125C
Operating Temperature (min)
-40C
Dual Supply Voltage (typ)
Not RequiredV
Dual Supply Voltage (max)
Not RequiredV
Dual Supply Voltage (min)
Not RequiredV
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
3.19
3.19.1
14
Watchdog
ATA6621N
Typical Timing Sequence with R
Figure 3-8.
For programming purposes at the microcontroller it is potentially necessary to supply the VCC
output via an external supply while the VS pin of the system basis chip is disconnected. This
behavior is no problem for the system basis chip.
The watchdog anticipates a trigger signal from the microcontroller at the NTRIG (negative edge)
or the PTRIG (positive edge) input within a period time window of t
exceed a minimum time t
generated at output NRES. The timing basis of the watchdog is provided by the internal oscilla-
tor, of which the time period T
In Silent or Sleep mode, the watchdog is switched off to reduce current consumption.
Minimum time for first watchdog pulse is required after the undervoltage reset at NRES disap-
pears and is defined as lead time t
The trigger signal T
For example, with an external resistor of R
watchdog come out as follows:
t
t
t
t
t
After every reset the watchdog always starts with the lead time.
OSC
d
1
2
nres
= 3922
= 800
= 840
= 157
= 12.5 µs due to 51 k
12.5 µs = 10 ms
12.5 µs = 10.5 ms
12.5 µs = 49 ms
12.5 µs = 1.96 ms
Power Dissipation: Safe Operating Area versus V
Voltage V
wd_osc
wd
is adjustable between 2.9 ms and 33 ms via the external resistor R
40
30
20
50
45
35
25
55
10
15
0
S
5
= 51 k
trigmin
5
at Different Ambient Temperatures with R
6
osc
> 3 µs. If a triggering signal is not received, a reset signal will be
is adjustable via the external resistor R
7
d
.
8
9
10
wd_oscSC
11
V
S
12
(V)
= 51 k ±1%, the typical parameters of the
13
14
15
T
T
amb
CC
amb
16
= 125˚C
= 105˚C
Output Current and Supply
thja
17
wd
. The trigger signal must
= 35 K/W
18
wd_osc
19
(10 k to 120 k ).
4887I–AUTO–09/09
wd_osc
.