Pin 1 (RXD): The pin is an open-drain output and requires an external
pull-up resistor in the range of 1kΩ to 10kΩ to
function properly. Note that the minimum value
will depend on the VIO supply used. See
IOL in electrical specifications. If
the microprocessor paired with the transceiver
does not have an integrated pull-up, an external
resistor should be placed between RXD and the
regulated voltage supply for the
microprocessor.
Pin 2 (EN): EN is an input pin that is used to place the device in a
low-power sleep mode. If this feature is not used
the pin should be pulled high to the regulated
voltage supply of the microprocessor through a
series resistor between 1kΩ and 10kΩ.
Additionally, a series resistor may be placed on
the pin to limit current on the digital lines in
the case of an over voltage fault.
Pin 3 (NC): Not Connected.
Pin 4 (TXD): The TXD pin is used to transmit the input signal from the microcontroller. A series resistor can be placed to limit the input current to the device in the case of an over-voltage on this pin. A capacitor to ground can be placed close to the input pin of the device to filter noise.
Pin 5 (GND): This is the ground connection for the device. This pin should be tied to the ground plane through a short trace with the use of two vias to limit total return inductance.
Pin 6
(LIN): This pin connects to the LIN bus. For
responder mode applications, a 220pF capacitor to
ground is implemented. For commander mode
applications, an additional series resistor and
blocking diode should be placed between the LIN
pin and the VSUP pin. See Figure 8-1.
Pin 7 (VSUP): This is the supply pin for the device. A 100 nF decoupling capacitor should be placed as close to the device as possible.
Pin 8 (NC): Not Connected.
Note:
All ground and power connections should be made as short as possible and use at least two vias to minimize the total loop inductance.