MCP6541-E/MF MICROCHIP [Microchip Technology], MCP6541-E/MF Datasheet - Page 7

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

1.5
TABLE 1-3:
1.5.1
The Receive Data Output pin is a standard CMOS
output and follows the state of the LIN pin.
The LIN receiver monitors the state of the LIN pin and
generates the output signal RXD.
1.5.2
Chip Select Input pin. This pin controls whether the part
goes into READY1 or READY mode at power-up. The
internal pull-down resistor will keep the CS/WAKE pin
low. This is done to ensure that no disruptive data will
be present on the bus while the microcontroller is
executing a Power-on Reset and I/O initialization
sequence. The pin must see a low-to-high transition to
activate the transmitter.
After CS/WAKE transitions to ‘1’, the transmitter is
enabled. If CS/WAKE = ‘0’, the device is in Ready1
mode on power-up or in Low-Power mode. In Low-
Power mode, the voltage regulator is shut down, the
transmitter driver is disabled and the receiver logic is
enabled.
An external switch (see Figure 1-2) can then wake up
both the transceiver and the microcontroller. An
external-blocking diode and current-limiting resistor are
necessary to protect the microcontroller I/O pin.
© 2007 Microchip Technology Inc.
8-Pin PDIP/
Legend: TTL = TTL input buffer,
SOIC/DFN
Note:
Devices
1
2
3
4
5
6
7
8
Pin Descriptions
HV = High Voltage (V
RECEIVE DATA OUTPUT (RXD)
CS/WAKE
On POR, the MCP201 enters Ready or
Ready1 mode (see Figure 1-1). In order to
enter Operational mode, the MCP201 has
to see one rising edge on CS/WAKE
600 µs after the voltage regulator reaches
5V.
RXD
CS/WAKE
V
TXD
V
LIN
V
FAULT/SLPS Fault Detect Output,
REG
SS
BAT
Bond Pad
MCP201 PINOUT OVERVIEW
Name
Receive Data Output
(CMOS output)
Chip Select (TTL-HV
input)
Power Output
Transmit Data Input
(TTL)
Ground
LIN bus (bidirectional-
HV)
Battery
Slope Select Input
Normal Operation
BAT
)
Function
1.5.3
Positive Supply Voltage Regulator Output pin.
1.5.4
The Transmit Data Input pin has an internal pull-up to
V
and high (recessive) when TXD is high.
In case the thermal protection detects an over-temper-
ature condition while the signal TXD is low, the
transmitter is shutdown. The recovery from the thermal
shutdown is equal to adequate cooling time.
1.5.5
Ground pin.
1.5.6
The bidirectional LIN bus Interface pin is the driver unit
for the LIN pin and is controlled by the signal TXD. LIN
has an open collector output with a current limitation.
To reduce EMI, the edges during the signal changes
are slope-controlled.
1.5.7
Battery Positive Supply Voltage pin. This pin is also the
input for the internal voltage regulator.
1.5.8
FAULT Detect Output, Slope Select Input.
This pin is usually in Output mode. Its state is defined
as shown in Table 1-5.
The state of this pin is internally sampled during power-
on of V
(approximately 6 VDC) and V
5.25 VDC, the state of this pin selects which slew rate
profile to apply to the LIN output. It is only during this
time that the pin is used as an input (the output driver
is off during this time). The slope will stay selected until
the next V
less of any power-down, wake-up or SLEEP events.
Only a V
FAULT/SLPS pin. The Slope selection will be made
irrespective of the state of any other pin.
The FAULT/SLPS pin is connected to either V
V
the slope selection. This large resistance allows the
FAULT indication function to overdrive the resistor in
normal operation mode.
If the FAULT/SLPS is high (‘1’), the normal slope shap-
ing is selected (dv/dt = 2 V/µs). If FAULT/SLPS is low
(‘0’) during this time, the alternate slope-shaping is
selected (dv/dt = 4 V/µs). This mode can be used if a
user desires to run at a faster slope. This mode is not
LIN compliant.
REG
SS
through a resistor (approximately 100 kΩ) to make
. The LIN pin is low (dominant) when TXD is low,
BAT
BAT
BAT
. Once V
POWER OUTPUT (V
TRANSMIT DATA INPUT (TXD)
GROUND (V
LIN
BATTERY (V
FAULT/SLPS
rising state will cause a sampling of the
power-off/power-on sequence, regard-
BAT
has reached a stable level,
SS
BAT
)
REG
)
MCP201
is stable at 4.75 to
REG
DS21730F-page 7
)
REG
or