ata6621n ATMEL Corporation, ata6621n Datasheet - Page 4

• Manufacturer Part Number: ata6621n
• Description: Lin Transceiver With 5v Regulator And Watchdog
• Manufacturer: ATMEL Corporation

3. Functional Description
3.1
3.2
3.3
3.4
3.5
3.6
4
Physical Layer Compatibility
Supply Pin (VS)
Ground Pin (GND)
Undervoltage Reset Output (NRES)
Voltage Regulator Output Pin (VCC)
Voltage Regulator Sense Pin (PVCC)
ATA6621N
Since the LIN physical layer is independent from higher LIN layers (e.g., the LIN protocol layer),
all nodes with a LIN physical layer according to revision 2.0 can be mixed with LIN physical layer
nodes, which, according to older versions (i.e., LIN 1.0, LIN 1.1, LIN 1.2, LIN 1.3), are without
any restrictions.
The LIN operating voltage is V
able transmission if V
NRES switches to low and the IC enters pre-normal mode. After switching on VS, the IC starts
with the Pre-normal mode and the voltage regulator is switched on (that is, 5V/50 mA output
capability).
The supply current in Sleep mode is typically 10 µA, and 40 µA in Silent mode.
The IC is neutral on the LIN pin in case of GND disconnection; it can handle a ground shift up to
3V for supply voltage at the VS pin above 9V.
This push-pull output is supplied from the V
voltage detection threshold of V
except the IC is switched into Sleep mode. Even if V
internally driven from the V
then becomes highly resistant.
The implemented undervoltage delay keeps NRES low for t
normal value.
The internal 5V voltage regulator is capable of driving loads with up to 50 mA of current con-
sumption; it is able to supply the microcontroller and other ICs on the PCB. It is protected
against overloads by means of current limitation and overtemperature shutdown. Furthermore,
the output voltage is monitored and will cause a reset signal at the NRES output pin if the output
voltage drops below a defined threshold V
nal NPN transistor may be used with its base connected to the VCC pin and its emitter
connected to PVCC.
This is the sense input pin of the 5V voltage regulator. For normal applications (that is, when
only using the internal output transistor), this pin is connected to the VCC pin. If an external
boosting transistor is used, the PVCC pin must be connected to the output of this transistor, its
emitter terminal.
S
falls below 5V in order to avoid false bus messages. In this case the
S
voltage. If V
S
= 5V to 18V. An undervoltage detection is implemented to dis-
thun
, NRES switches to low after t
S
thun
voltage ramps down, NRES stays until V
CC
. To boost up the maximum load current, an exter-
voltage. If the V
CC
= 0V the NRES stays low, because it is
Reset
CC
= 10 ms after V
voltage falls below the under-
res_f
(Figure 3-7 on page
4887H–AUTO–12/07
CC
S
reaches its
< 1.5V and
13)