MCP6541-E/MF MICROCHIP [Microchip Technology], MCP6541-E/MF Datasheet - Page 4

• Manufacturer Part Number: MCP6541-E/MF
• Description: LIN Transceiver with Voltage Regulator
• Manufacturer: MICROCHIP [Microchip Technology]

MCP201
1.3
For an overview of all operational modes, please refer
to Table 1-2.
1.3.1
In the Power-down mode, the transmitter and the
voltage regulator are both off. Only the receiver section
and the CS/WAKE pin wake-up circuits are in
operation. This is the lowest power mode.
If any bus activity (e.g., a BREAK character) should
occur during Power-down mode, the device will
immediately enable the voltage regulator. Once the
output has stabilized, the device will enter Ready
mode.
The part will enter the Operation mode, if the CS/WAKE
pin should become active-high (‘1’).
1.3.2
There are two states for the Ready mode. The only
difference between these states is the transition during
start-up. The state Ready1 mode ensures that the
transition from Ready to Operation mode (once a rising
edge of CS/WAKE) occurs without disrupting bus
traffic.
Immediately upon entering either Ready1 or Ready
mode, the voltage regulator will turn on and provide
power. The transmitter portion of the circuit is off, with
all other circuits (including the receiver) of the MCP201
being fully operational. The LIN pin is kept in a
recessive state.
If a microcontroller is being driven by the voltage
regulator output, it will go through a power-on reset and
initialization sequence. All other circuits, other than the
transmitter, are fully operational. The LIN pin is held in
the recessive state.
The device will stay in Ready mode until the CS/WAKE
pin transitions high (‘1’). After CS/WAKE is active, the
transmitter is enabled and the device enters Operation
mode.
The device may only enter Power-down mode after
going through the Operation mode step.
At power-on of the V
in either Ready or Ready1 mode, waiting for a
CS/WAKE rising edge.
The MCP201 will stay in either mode for 600 µs as the
regulator powers its internal circuitry and waits until the
CS/WAKE pin transitions high. During the 600 µs
delay, the MCP201 will not recognize a CS/WAKE
event. The CS/WAKE transition from low to high should
not occur until after this delay.
• The CS input is edge, not level, sensitive.
• The CS pin is not monitored until approximately
• The transistion from Ready1 to Ready is made on
• The transition from Ready mode to Operational
DS21730F-page 4
600 µs after V
the falling edge of CS.
mode is on the rising edge of CS.
Modes of Operation
POWER-DOWN MODE
READY AND READY1 MODES
REG
has stabized.
BAT
supply pin, the component is
1.3.3
In this mode, all internal modules are operational.
The MCP201 will go into Power-down mode on the
falling edge of CS/WAKE.
FIGURE 1-1:
1.3.4
As V
V
is greater than 5.5 - 6.0 VDC.
As V
V
The MCP201 monitors V
not fall below V
ifications”), V
As V
until V
If V
MCP201 powers itself down.
The MCP201 will remain powered down until V
increases above V
Specifications”.
CS/WAKE = true
REG
BAT
Note:
Note:
REG
BAT
BAT
BAT
- (0.5 to 1.0) VDC.
in Section 2.2 “DC Specifications”) while V
REG
Operation
falls below V
decreases V
decreases further V
increases V
Mode
reaches 5.0 VDC.
OPERATION MODE
After power-on, CS will not be sampled
until V
600 µs has elapsed. The microcontroller
should toggle CS approximately 1mS after
RESET to ensure that CS will be recog-
nized.
While the MCP201 is in shutdown, TXD
should not be actively driven high. If TXD
is driven high actively, it may power
internal logic.
DESCRIPTION OF BROWNOUT
CONDITIONS
CS/WAKE = false
REG
SD
Ready1
REG
(see V
Power-down
Mode
will remain powered.
ON
CS/WAKE = true
REG
REG
Mode
SD
OPERATIONAL MODES
STATE DIAGRAMS
has stabized and an additional
(see V
© 2007 Microchip Technology Inc.
REG
, V
SD
is regulated to 5.0 VDC (see
will continue to track V
REG
in Section 2.2 “DC Spec-
CS/WAKE = false
CS/WAKE = true
and as long as V
REG
ON
is turned off and the
tracks V
in Section 2.2 “DC
Ready
Mode
Bus Activity
BAT
REG
Start
POR
(V
REG
does
BAT
BAT
BAT
=