MCP2021-330E-P MICROCHIP [Microchip Technology], MCP2021-330E-P Datasheet - Page 12

• Manufacturer Part Number: MCP2021-330E-P
• Description: LIN Transceiver with Voltage Regulator
• Manufacturer: MICROCHIP [Microchip Technology]

MCP2021/2/1P/2P
1.4
TABLE 1-1:
1.4.1
Positive Supply Voltage Regulator Output pin.
1.4.2
Ground pin.
1.4.3
Battery Positive Supply Voltage pin. This pin is also the
input for the internal voltage regulator.
1.4.4
The Transmit Data Input pin has an internal pull-up to
V
and high (recessive) when TXD is high.
For extra bus security, TXD is internally forced to ‘1’
when V
If the thermal protection detects an over-temperature
condition while the signal TXD is low, the transmitter is
shut down. The recovery from the thermal shutdown is
equal to adequate cooling time.
1.4.5
The Receive Data Output pin is a standard CMOS
output and follows the state of the LIN pin.
1.4.6
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. To further reduce radiated emis-
sions, the L
falling and rising edges.
DS22018F-page 12
Legend: O = Output, P = Power, I = Input, TTL = TTL input buffer, OD = Open-Drain output
REG
FAULT/TXE
CS/LWAKE
RESET
Name
. The LIN pin is low (dominant) when TXD is low,
V
L
TXD
RXD
V
V
Pin
REG
BUS
REG
SS
BB
Pin Descriptions
BUS
POWER OUTPUT (V
GROUND (V
BATTERY (V
TRANSMIT DATA INPUT (TXD)
RECEIVE DATA OUTPUT (RXD)
LIN BUS
is less than 1.8V (typ.).
pin has corner-rounding control for both
PINOUT DESCRIPTIONS
8-Pin
PDIP,
SOIC
DFN,
—
3
5
7
4
1
6
2
8
Devices
SS
BB
)
)
TSSOP
14-Pin
SOIC,
PDIP,
11
13
12
14
3
4
1
2
5
REG
)
Type
TTL
Pin
OD
OD
I/O
O
O
P
P
I
Power Output
Ground
Battery Supply
Transmit Data Input (TTL)
Receive Data Output (CMOS)
LIN bus (bidirectional)
Chip Select (TTL)
Fault Detect Output, Transmitter Enable (OD)
RESET signal Output (OD)
The internal LIN receiver observes the activities on the
LIN bus, and generates output signal RXD that follows
the state of the L
stant (160KhZ), low-pass input filter is placed to
maintain EMI immunity.
1.4.7
Chip Select Input pin. A internal pull-down resistor will
keep the CS/LWAKE pin low. This is done to ensure
that no disruptive data will be present on the bus while
the microcontroller is executing a POR and I/O initial-
ization sequence. The pin must see a high level to
activate the transmitter.
If CS/LWAKE= ‘0’ when the V
the device stays in Ready mode (Low-Power mode). In
Ready mode, both the receiver and the voltage
regulator are on and the LIN transmitter driver is off.
If CS/LWAKE = ‘1’ when the V
the device will proceed to either Operation or Transmit-
ter-Off mode (refer to
the V
This pin may also be used as a local wake-up input
(see
troller will set the I/O pin that controls the CS/LWAKE
as an high-impedance input. The internal pull-down
resistor will keep the input low. An external switch, or
other source, can then wake up the transceiver and the
microcontroller.
Note:
Figure
REG
output has stabilized.
CS/LWAKE
CS/LWAKE should not be tied directly to
V
Operation
microcontroller is initialized.
1-6). In this implementation, the microcon-
Normal Operation
REG
BUS
Function
as this could force the MCP202x into
© 2005-2012 Microchip Technology Inc.
. A 1
Figure 1-2
st
degree with 1 µS time con-
mode
BB
BB
and
supply is turned on,
supply is turned on,
Figure
before
1-3) after
the