M
Features
•
•
•
•
•
•
MCP201
Package Types
PDIP, SOIC
RXD
CS/WAKE
V
DD
TXD
1
MCP201
2
3
4
8
FAULT/SLPS
V
BAT
LIN
V
SS
LIN Transceiver with Voltage Regulator
Support Baud Rates up to 20 kbaud
40V load dump protected (<500 ms)
Wide supply voltage, 6.0-18.0V
Extended Temperature Range: -40 to +125°C
Interface to standard USARTs
Local Interconnect Network (LIN) Line pin:
- Internal pull-up resistor and diode
- Protected against ground shorts
- Protected against loss of ground
- High current drive, 40 mA
≤
I
OL
≤
200 mA
• Automatic thermal shutdown
• On-board Voltage Regulator:
- Output voltage of 5V with tolerances of ±5%
over temperature range
- Maximum output current of 50 mA
- Able to drive an external series-pass
transistor for increased current supply
capability
- Maximum input voltage of 30V
- Internal thermal overload protection
- Internal short circuit current limit
- Only external filter capacitors needed
7
6
5
BLOCK DIAGRAM
Voltage
Regulator
Ratiometric
Reference
V
DD
Internal Circuits
Wake-Up
Logic
V
BAT
RXD
CS/WAKE
TXD
FAULT/SLPS
POR
Slope
Control
Thermal
Protection
OC
V
SS
approx. 30 k
Ω
LIN
2002 Microchip Technology Inc.
Preliminary
DS21730B-page 1
MCP201
NOTES:
DS21730B-page 2
Preliminary
2002 Microchip Technology Inc.
MCP201
1.0
DEVICE OVERVIEW
1.1.2
REVERSE BATTERY PROTECTION
The MCP201 provides a physical interface between a
microcontroller and a LIN half-duplex bus. It is intended
for automotive and industrial applications with serial
bus speeds up to 20 kbaud.
The MCP201 provides a half-duplex, bi-directional
communications interface between a microcontroller
and the serial network bus. This device will translate
the CMOS/TTL logics levels to LIN level logic, and vice
versa.
The LIN specification 1.2 requires that the transceiver
of all nodes in the system be connected via the LIN pin,
referenced to ground, and with a maximum external
termination resistance of 510Ω from LIN bus to battery
(510Ω is the maximum load of the LIN bus, which
corresponds to one Master and 16 Slave nodes).
An external reverse battery blocking diode should be
used to provide polarity protection (see Figure 1-2).
1.2
1.2.1
Internal Protection
ESD PROTECTION
This device is designed to meet IEC 1000-4-2:1995
specifications.
1.2.2
GROUND LOSS PROTECTION
The LIN bus specification states that an inactive node
must assume the recessive state. Therefore, loss of
ground effectively forces the LIN line to a hi-impedance
level.
1.2.3
THERMAL PROTECTION
1.1
1.1.1
External Protection
TRANSIENT VOLTAGE
PROTECTION (LOAD DUMP)
The Thermal Protection circuit monitors the die temper-
ature and is able to shutdown the LIN transmitter and
voltage regulator. Refer to Table 1-1 for details.
There are two sources for a thermal overload. One is
the voltage regulator, which can have an output over-
load, the other is the LIN transmitter with a short circuit
to V
BAT
. Checking the TXD and RXD states make it
possible to determine the thermal excursion source
and to shut it down.
An external 30V zener diode, between V
BAT
and
ground, with a 50Ω resistor in series with the battery
supply and the V
BAT
pin, protect the device from power
transients (see Figure 1-2).
TABLE 1-1:
TXD
x
L
L
H
SOURCES OF THERMAL OVERLOAD
RXD
x
L
H
H/L
LIN Transmitter
(1)
ok
output overload
short circuit
ok
Voltage
Regulator
(2)
ok
output overload
ok
output overload
Normal function
LIN Transmitter and regulator shutdown
LIN Transmitter shutdown
Regulator shutdown
Comments
Legend: x = Don’t care, L = Low, H = High
Note 1:
LIN transceiver overload current on the LIN pin is >200 mA.
2:
Voltage regulator overload current on V
DD
is >50 mA.
2002 Microchip Technology Inc.
Preliminary
DS21730B-page 3
MCP201
1.3
Modes of Operation
1.3.3
OPERATION MODE
For an overview of all Operational modes, please refer
to Table 1-2.
In this mode, all internal modules are operational.
The MCP201 will go into the Power-down mode on the
falling edge of CS/WAKE.
1.3.1
POWER-DOWN MODE
In the Power-down mode, the transmitter and the volt-
age regulator are both off. Only the receiver section,
and the CS/WAKE pin wake-up circuits are in opera-
tion. This is the lowest Power mode.
If any bus activity (e.g., a BREAK character) should
occur during Power-down mode, the device will imme-
diately enable the voltage regulator, and once the out-
put has stabilized, enter the Ready mode.
The part will enter the Operation mode if the CS/WAKE
pin should become active high (‘1’).
FIGURE 1-1:
OPERATIONAL MODES
STATE DIAGRAMS
Power-down
Mode
CS/WAKE = true
Bus Activity
CS/WAKE = false
Operation
Mode
Ready
Mode
1.3.2
READY MODE AND READY1 MODE
CS/WAKE = true
There are two states for the Ready mode.The
differences between the states are only the transition
during start-up of the regulator depending on the signal
CS/WAKE. The state Ready1 mode ensures that the
transition from the Ready mode to Operation mode,
after an active edge of CS/WAKE, occurs.
Upon entering the Ready mode, the voltage regulator
is powered up. 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 the Ready mode until the
CS/WAKE pin goes high (‘1’). After CS/WAKE is active,
the transmitter is enabled and the part enters the
Operation mode.
The part may only enter the Power-down mode after
going through an Operation mode step.
On Power-on of the V
BAT
supply pin, the component is
in either in Ready or Ready1 mode, waiting for a CS/
WAKE rising edge.
POR
CS/WAKE = false
Ready1
Mode
CS/WAKE = true
Start
DS21730B-page 4
Preliminary
2002 Microchip Technology Inc.
CS/WAKE = false
MCP201
TABLE 1-2:
State
POR
OVERVIEW OF OPERATIONAL MODES
Transmitter
OFF
Voltage Regulator
OFF
Operation
Comments
Read CS/WAKE, if LOW then Sample FAULT/SLPS and
READY, if HIGH READY1
select slope
mode
If CS/WAKE rising edge, then Bus Off state
Operation mode
If CS/WAKE falling edge,
then READY mode
If CS/WAKE falling edge,
then Power down
Bus Off state
Normal Operation mode
READY
READY1
OPERATION
POWERDOWN
OFF
OFF
ON
OFF
ON
ON
ON
OFF
On LIN bus falling, go to
Low Power mode
READY mode. On CS/WAKE
rising edge, go to Operational
mode
2002 Microchip Technology Inc.
Preliminary
DS21730B-page 5
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