Pins 1, 4, 7 and 10 (RXD1/2/3/4): The pins are 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.
Pins 2, 5, 8 and 11 (EN1/2/3/4): 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 case of an over voltage fault.
Pin 13, 18, 23 and 24 (NC): Not Connected
Pins 3, 6, 9 and 12 (TXD1/2/3/4): The TXD pins are the transmitter input signals to the device from the microprocessor. A series resistor can be placed to limit the input current to the device in the case of an overvoltage on this pin. A capacitor to ground can be placed close to the input pin of the device to filter noise.
Pin 14, 19 (GND2/1): 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.
Pins 22, 20, 17 and 15 (LIN1/2/3/4): This pin connects to the LIN bus.
For responder node applications a 220 pF capacitor to ground is implemented.
For commander node applications and additional series resistor and blocking
diode should be placed between the LIN pin and the VSUP1/2
pin.
Pin 21, 160 (VSUP1/2): This is the supply pin for the device. A 100 nF decoupling capacitor should be placed as close to the device as possible.
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.