Datasheet

TB3067
DS93067A-page 2 © 2011 Microchip Technology Inc.
To prevent an undesired wake-up scenario in a LIN bus
loss situation, the Power-Down mode has to be entered
via the Transmitter-Off mode observing specific timings
and the switching sequence outlined below (“Forced
Power-Down mode”).
The following state machine diagram shows the paths
to enter the MCP2003 Power-Down mode from
Operation mode or Transmitter-Off mode.
To enter Power-Down mode from Ready mode, the
MCP2003 has two different paths:
• Passing through Transmitter-Off mode (T
OFF
),
which is shown in red in Figure 2
• Passing through Operating mode, which is shown
in blue in Figure 2
FIGURE 2: Entering MCP2003 Power-Down Mode From Operation Mode or Transmitter-Off Mode.
The Forced Power-Down mode sequence is used to
enter Power-Down mode without activating the
transceiver to reduce the current consumption of the
transceiver. After the device is in Ready mode, this path
could be selected by holding TXD and CS in low state
for t
TX2CS
, and then setting CS to ‘1’ for t
CSactive
before resetting CS to ‘0’. This results in all functionality
being disabled in the transceiver until CS goes high or
a falling edge on LIN bus had been detected.
POR
VREN OFF
RX OFF
TX OFF
Ready Mode
VREN ON
RX ON
TX OFF
VBAT > 5.5V
Falling Edge
on LIN or CS = 1
TOFF Mode
VREN ON
RX ON
TX OFF
Power-Down
Mode
VREN OFF
RX OFF
TX OFF
CS = 1 and TXD = 1
CS = 1 and TXD = 1
and No Fault
Fault
(Thermal or Timer)
CS = 0
CS = 0
Operation
Mode
VREN ON
RX ON
TX ON
CS = 1 and TXD = 0*
Note: * TXD = 0 before raising CS to ‘1’.