TLIN1029-Q1: Schematic review

Hi Kygo,

Kygo Cheng said:

1. I want to confirm with you, what is the maximum input current of TLIN1029Q1 under normal operation? I want to confirm the specifications of the LDO from my side

The maximum supply current for this device is 5 mA. This is when the device is in normal mode and the LIN bus is pulling dominant. This measurement is also assuming that the resistance of your bus is higher than 500 ohms and the capacitance is less than 10 nF.

Here is my schematic review:

• Pinout on schematic matches pinout on datasheet: Correct
• Decoupling capacitors included and valued well: Correct
• Pullup between 1k-10k on RXD: Correct
• The series resistors on RXD and TXD are fine just make sure they are as close to the transmitter as possible
  • For RXD this is the LIN device for TXD this is the LIN controller or MCU
• Pullup on TXD is fine

LIN Bus

• I am going to assume this is a Leader (formerly master) node. If this is not a Leader node let me know.
• External 1k pull up included: Incorrect
  • It looks like you included an external pull up resistor and diode. This is fine however the resistor is 30k not 1k.
• In the current setup having pin 8 and VSUP connecting is fine
  • With other TI LIN devices you should not pull up the LIN bus to INH. You should have it pulled up to VSUP.
  • Since this device has pin 8 as a NC it is fine.
• Included capacitor is valued well: Correct.
• Included Zener diode is fine just make sure it is placed close and along the signal path.
  • Ensure that the breakdown voltage is high enough to withstand your LIN bus voltage,

Best,

Chris