Pin 1, 4 (RXD1/2): The pin is an open drain outputs and require an external pull-up resistor in the range of 1 k? and 10 k? to function properly. 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, 5 (EN1/2): 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, values between 1 k? and 10 k?. Additionally, a series resistor may be placed on the pinto limit current on the digital lines in the event of an over voltage fault.
Pin 6 (NC): Not Connected.
Pin 3, 7 (TXD1/2): The TXD pins are the transmitter input signals to the device from the processor. 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 8 (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 9, 13 (LIN1/2): This pin connects to the LIN bus. For responder applications, a 220 pF capacitor to ground is implemented. For commander applications and additional series resistor, a blocking diode should be placed between the LIN pin and the VSUP pin. See Figure 8-1.
Pin 10 (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 11, 12 and 14 (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.