TLIN1028S-Q1: Difference with TLIN1028-Q1

Kuramochi-san,

Great question! Let me walk through some of the differences.

RXD Mode Transition Performance

These devices have different RXD performance during mode transitions. Take a look at the graphic below that highlights a difference in their behaviors. The annotated graphics are borrowed from the devices' respective datasheets.

During a transition into Standby mode from Normal mode, Standby INIT mode, or TSD Off mode, when a LIN bus wake event occurs, the RXD pin is latched low in the TLIN1028-Q1, while the RXD pin will remain high in the TLIN1028S-Q1.

During a transition into Standby mode from Sleep mode, both devices pull RXD low and latch it in Standby.

RXD Transmitter Behavior (Standby to Normal with TXD Dominant)

During a transition from Standby mode to Normal mode with TXD dominant, for the TLIN1028-Q1, the RXD pin is floating but pulled high by an external pull-up resistor, meaning that RXD will not reflect the bus until a TXD transition to recessive. This is because the LIN transmitter is turned off until the first TXD transition to recessive, at which point the transmitter is turned on and RXD will reflect TXD and the LIN bus.

During a transition from Standby mode to Normal mode with TXD dominant, for the TLIN1028S-Q1, a low-to-high-to-low pulse might be seen on the RXD pin within t_{MODE_CHANGE}, not accurately reflecting the bus. As indicated in the figure above, RXD should be ignored during this time. This is because the LIN transmitter is turned on immediately and the dominant on TXD will be reflected on the RXD pin.

State Diagrams

You can also see this shown in the state diagrams for these devices.

Here is TLIN1028-Q1:

and here is TLIN1028S-Q1:

Best,

Danny

Kuramochi-san,

The devices are the same aside from the functional differences outlined in my prior post.

The TLIN1028-Q1 signals a transition to standby by latching low on RXD, while the TLIN1028S-Q1 does not do this. The TLIN!028S-Q1 instead allows RXD to remain high.

During a transition to normal mode, the TLIN1028-Q1 keeps the LIN transmitter off until TXD transitions to recessive. The TLIN1028S-Q1, on the other hand, turns on the transmitter immediately, but the tradeoff is that this may cause a low-to-high-to-low transition on the RXD pin that doesn't reflect the bus. This occurs during t_{MODE_CHANGE}, during which time the RXD state should be ignored in design.

Best,

Danny