MCP2003/4
LIN J2602 Transceiver
Features
• The MCP2003 and MCP2004 are compliant with
LIN Bus Specifications 1.3, 2.0 and 2.1 and are
compliant to SAE J2602
• Support Baud Rates up to 20 Kbaudwith
LIN-compatible output driver
• 43V load dump protected
• Very low EMI meets stringent OEM requirements
• Very high ESD immunity:
- >20kV on VBB (IEC 61000-4-2)
- >14kV on LBUS (IEC 61000-4-2)
• Very high immunity to RF disturbances meets
stringent OEM requirements
• Wide supply voltage, 6.0V-27.0V continuous
• Extended Temperature Range: -40 to +125°C
• Interface to PIC
®
MCU EUSART and standard
USARTs
• Local Interconnect Network (LIN) bus pin:
- Internal pull-up resistor and diode
- Protected against battery shorts
- Protected against loss of ground
- High current drive
• Automatic thermal shutdown
• Low-power mode:
- Receiver monitoring bus and transmitter off,
(
5 µA)
Description
This device provides a bidirectional, half-duplex
communication physical interface to automotive and
industrial LIN systems to meet the LIN bus specification
Revision 2.1 and SAE J2602. The device is short circuit
and overtemperature protected by internal circuitry.
The device has been specifically designed to operate in
the automotive operating environment and will survive
all specified transient conditions while meeting all of the
stringent quiescent current requirements.
MCP200X family members:
• 8-pin PDIP, DFN and SOIC packages:
- MCP2003, LIN-compatible driver, with WAKE
pins
- MCP2004, LIN-compatible driver, with
FAULT/TXE pins
Package Types
MCP2003
PDIP, SOIC
R
XD
1
CS 2
WAKE 3
T
XD
4
8 V
REN
7 V
BB
MCP2004
PDIP, SOIC
R
XD
1
CS 2
8 V
REN
7 V
BB
6 L
BUS
5 V
SS
6 L
BUS
FAULT/TXE 3
5 V
SS
T
XD
4
MCP2003
4x4 DFN*
R
XD
1
CS 2
WAKE 3
T
XD
4
EP
9
8 V
REN
7 V
BB
MCP2004
4x4 DFN*
R
XD
1
CS 2
EP
9
8 V
REN
7 V
BB
6 L
BUS
5 V
SS
6 L
BUS
FAULT/TXE 3
T
XD
4
5 V
SS
* Includes Exposed Thermal Pad (EP); see
Table 1-1.
2010 Microchip Technology Inc.
DS22230C-page 1
MCP2003/4
MCP2003 Block Diagram
V
REN
Ratiometric
Reference
WAKE
Wake-Up
Logic and
Power Control
V
BB
R
XD
CS
T
XD
OC
~30 k
L
BUS
V
SS
Thermal
Protection
Short Circuit
Protection
MCP2004 Block Diagram
V
REN
Ratiometric
Reference
Wake-Up
Logic and
Power Control
R
XD
CS
~30 k
V
BB
T
XD
FAULT/TXE
OC
L
BUS
V
SS
Thermal
Protection
Short Circuit
Protection
DS22230C-page 2
2010 Microchip Technology Inc.
MCP2003/4
1.0
DEVICE OVERVIEW
1.2.3
THERMAL PROTECTION
The MCP2003/4 provides a physical interface between
a microcontroller and a LIN bus. This device will
translate the CMOS/TTL logic levels to LIN logic level,
and vice versa. It is intended for automotive and
industrial applications with serial bus speeds up to
20 Kbaud.
LIN specification 2.1 requires that the transceiver of all
nodes in the system is connected via the LIN pin, refer-
enced to ground and with a maximum external
termination resistance of 510 from LIN bus to battery
supply. The 510 corresponds to 1 master and
15 slave nodes.
The V
REN
pin can be used to drive the logic input of an
external voltage regulator. This pin is high in all modes
except for Power-Down mode.
The thermal protection circuit monitors the die
temperature and is able to shut down the LIN
transmitter.
There are two causes for a thermal overload. A thermal
shut down can be triggered by either, or both, of the
following thermal overload conditions.
• LIN bus output overload
• Increase in die temperature due to increase in
environment temperature
Driving the T
XD
and checking the R
XD
pin makes it pos-
sible to determine whether there is a bus contention
(Rx = low, Tx = high) or a thermal overload condition
(Rx = high, Tx = low). After a thermal overload event,
the device will automatically recover once the die tem-
perature has fallen below the recovery temperature
threshold. See
Figure 1-1.
1.1
1.1.1
External Protection
REVERSE BATTERY PROTECTION
FIGURE 1-1:
THERMAL SHUTDOWN
STATE DIAGRAM
LIN bus
Shorted
to V
BB
Operation
Mode
Transmitter
Shutdown
An external reverse-battery-blocking diode should be
used to provide polarity protection (see
Example 1-1).
1.1.2
TRANSIENT VOLTAGE
PROTECTION (LOAD DUMP)
An external 43V transient suppressor (TVS) diode,
between V
BB
and ground, with a 50 transient
protection resistor (R
TP
) in series with the battery
supply and the V
BB
pin serve to protect the device from
power transients (see
Example 1-1)
and ESD events.
While this protection is optional, it is considered good
engineering practice.
Temp <
SHUTDOWN
TEMP
1.2
1.2.1
Internal Protection
ESD PROTECTION
For component-level ESD ratings, please refer to the
maximum operation specifications.
1.2.2
GROUND LOSS PROTECTION
The LIN Bus specification states that the LIN pin must
transition to the recessive state when ground is
disconnected. Therefore, a loss of ground effectively
forces the LIN line to a high-impedance level.
2010 Microchip Technology Inc.
DS22230C-page 3
MCP2003/4
1.3
Modes of Operation
For an overview of all operational modes, refer to
Table 1-1.
the T
XD
pin is held low when CS goes high, the device
will transition to Transmitter Off mode instead of
Operation mode.
1.3.1
POWER-DOWN MODE
1.3.3
OPERATION MODE
In Power-Down mode, the transmitter and V
REN
are
both off. Only the receiver section and the wake-up
circuits are operational. This is the lowest power
mode.
On bus activity (e.g. a BREAK character), CS going to
a high level, or on a falling edge on WAKE, the device
will immediately enter Ready mode. If CS is held high
as the device transitions from Power-Down to Ready
mode, the device will transition to Operation mode as
soon as internal voltages stabilize.
Note:
Bus activity is defined as LBUS dropping
below V
IL
(L
BUS
) for longer than the Bus
Activity Debounce time (tBDB)
In this mode, all internal modules are operational.
The MCP2003/4 will go into the Power-Down mode on
the falling edge of CS. The MCP2003/4 will enter
Transmitter Off mode in the event of a Fault condition.
These include: thermal overload, bus contention and
T
XD
timer expiration.
The MCP2004 device can also enter Transmitter Off
mode if the FAULT/TXE pin is pulled low
1.3.4
TRANSMITTER OFF MODE
1.3.2
READY MODE
Transmitter Off mode is reached whenever the
transmitter is disabled either due to a Fault condition or
pulling the nFAULT/TXE pin low on the MCP2004. The
fault conditions include: thermal overload, bus
contention or TXD timer expiration.
The MCP2003/4 will go into Power-Down mode on
falling edge of CS, or return to Operation mode if all
faults are resolved and the FAULT/TXE pin on the
MCP2004 is high.
Upon entering the Ready mode, V
REN
is enabled and
the receiver detect circuit is powered up. The transmit-
ter remains disabled and the device is ready to receive
data but not to transmit.
Upon VBB supply pin power-on, the device will remain
in Ready mode as long as CS is low. If CS transitions
high, the device will enter Operation mode. However, if
FIGURE 1-2:
OPERATIONAL MODES STATE DIAGRAM – MCP2003
POR
VREN OFF
RX OFF
TX OFF
VBAT > 5.5V
Ready
Mode
VREN ON
RX ON
TX OFF
CS =
1
and TXD =
1
CS =
1
and TXD
CS =
1
and
TXD =
1
and No Fault
Fault
(Thermal or Timer)
Falling edge
on LIN
or
CS =
1
TOFF
Mode
VREN ON
RX ON
TX OFF
Operation
Mode
VREN ON
RX ON
TX ON
CS =
0
CS =
0
Power-Down
Mode
VREN OFF
RX OFF
TX OFF
DS22230C-page 4
2010 Microchip Technology Inc.
MCP2003/4
FIGURE 1-3:
POR
VREN OFF
RX OFF
TX OFF
OPERATIONAL MODES STATE DIAGRAM – MCP2004
Ready
Mode
VREN ON
RX ON
TX OFF
VBAT > 5.5V
CS =
1
and (TXE =
0
or TXD =
0)
CS =
1
and
TXD =
1
and
TXE =
1
Falling edge on
LIN
or
CS =
1
TOFF
Mode
VREN ON
RX ON
TX OFF
CS =
1
and TXE =
1
and TXD =
1
and
No Fault
Fault
(Thermal or Timer)
or TXE =
0
Operation
Mode
VREN ON
RX ON
TX ON
CS =
0
CS =
0
Power-Down
Mode
VREN OFF
RX OFF
TX OFF
Note:
While the MCP2003/4 is in thermal shutdown, T
XD
should not be actively driven high or it may power
internal logic through the ESD diodes and may damage the device.
TABLE 1-1:
State
POR
Ready
Operation
OVERVIEW OF OPERATIONAL MODES
Transmitter Receiver
OFF
OFF
ON
OFF
ON
ON
Vren
OFF
ON
ON
Operation
Read CS, if low, then Ready;
if high, Operational mode
If CS high level, then Operation mode
Bus Off state
If CS low level, then Power Down;
Normal Operation
If FAULT/TXE low level, then Transmitter Off mode
mode
On LIN bus falling, go to Ready mode. On CS Low Power mode
high level, go to Operation mode
If CS low level, then Power Down;
FAULT/TXE only
If FAULT/TXE and TXD high, then Operation available on
mode
MCP2004
Comments
Power Down
Transmitter Off
OFF
OFF
Activity
Detect
ON
OFF
ON
2010 Microchip Technology Inc.
DS22230C-page 5
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