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Eric,

Sorry for the delay in getting back to you, I was out of the office last week.

Q1. If the wake-up function is not used, NWake should be connected to ground ? (Like freescale MC33662)

For the SN65HVDA100, the only time the NWAKE pin affects the mode is when the device is in sleep mode. If NWAKE is held low the device will go into sleep mode then immediately transfer into Standby Mode after tNWAKE. If the pin is held high (~VBatt) the device will have no local wake-up. It will remain in Sleep Mode until the EN pin is toggles high or a LIN bus Wake-Up request occurs. Therefore it depends how you want to use the device. This differs slightly from the Freescale device since when their device enters Sleep Mode it will save the current state of the WAKE pin and will leave Sleep mode whenever that pin is toggled. Therefore it could be either a low to high transition or a high to low transition that wakes the Freescale Part up from Sleep Mode. 

Q2. SN65HVDA100 Pin7 (NWake) recommended resistor value ?

The devices pin can be tied directly to ground (0Ω or 1Ω). If a resistor is used it needs to be small enough that the pull-up current does not cause a voltage across the external resistor large enough to not be seen as a logic low (voltage needs to be < Vsup - 3.3 volts).

Q3. Vbat to Vsup diode recommend?

I have seen both the 1N5711W and the BA260 diode used. 

Please let me know if you need anything else, again sorry for the delay.

John G

Eric,

Typo:

I meant to say B260 diode, NOT BA260.

John

Dear John,

Got it and thanks.

Best regards,

Eric Lo

Dear John,

Sorry, another question.

Do you have MC33390EF (J1850) replace suggestion?

Thanks for your support.

Best regards,

Eric Lo

Eric,

The J-1850 Class B device you mentioned is a variable pulse width modulation single wire interface that TI does not offer any devices in. Unfortunately I can not help you with this. 

John

Eric,

Whatever you have on your purchasing list that meets the LIN standard for the diode drop, and the max current spec of the device. You can use everything from power diodes to signal diodes without any issues.

• Parameter 21 of the LIN2.1 spec stats that the forward voltage drop of any serial diode cannot be greater than 1.0 volts (typical 0.7 volts)
• The SN65HVDA100-Q1 maximum supply current (domimant state) is 7.5 mA (Parameter 4.5 of the datasheet)