MLX80020 Datasheet, PDF (12/26 Pages) Melexis Microelectronic Systems – Enhanced LIN Transceiver

MLX80020
Enhanced LIN Transceiver
EN =>Low
Normal Mode
V_S on
EN
INH
RxD
receive
high
Vs
data
LIN termination 30kO
Transmitter on
EN =>High
t > 150ms
-> no mode change
-> no valid wake up
EN =>High
Standby
EN INH RxD TxD
low V_S floating low/
low^{[1] high[2]}
LIN termination 30kO
Transmitter off
Sleep Mode
EN
INH
RxD
low floating floating
LIN termination 200kO
Transmitter off
Remote or
local wake
up request
[1] _{floating after power on}
active low interrupt after wake up
[2] _{weak pull down after power on}
indicates wake up source via weak /strong pull down
Figure 3: State Diagram of the MLX80020
4.2 Initialization and Standby mode
When the battery supply voltage Vs exceeds the specified threshold V_{S_POR}, the MLX80020 automatically
enters an intermediate standby mode. The INH output becomes HIGH (Vs) and therefore the external
voltage regulator will provide the Vcc supply voltage to the ECU. The pin RxD is floating and the integrated
slave pull up resistor with decoupling diode secures high level on the pin LIN. The transmitter as well as the
receiver is disabled.
If there occurs no mode change to normal mode via an EN LOW to HIGH transition within the time defined
(typically 350ms), the IC enters the most power saving sleep mode and the INH output will become floating
(logic 0).
Furthermore the standby mode will be entered after a valid local or remote wake up event, when the
MLX80020 is in sleep mode. The entering of the standby mode after wake up will be indicated by an active
LOW interrupt on pin RxD.
4.3 Normal Mode
By entering this mode the MLX80020 can be used as interface between the single wire LIN bus and the
microcontroller. The incoming bus traffic is detected by the receiver and transferred via the RxD output pin to
the microcontroller. (see figure 3, LIN timing diagram)
MLX80020 – Datasheet
3901080020
Page 12 of 26
November 2015
Rev 006