MCP2021-330E/MF Microchip Technology, MCP2021-330E/MF Datasheet - Page 8

• Manufacturer Part Number: MCP2021-330E/MF
• Description: LIN COMPATIBLE DRIVER, 3.3V REGULATOR, -40C to +125C, 8-DFN, TUBE
• Manufacturer: Microchip Technology

MCP202X
1.5.8
Fault Detect output and Transmitter Enable input bidi-
rectional pin.
This pin is an open-drain output. Its state is defined as
shown in
whenever this pin is low (‘0’), either from an internal
fault condition or by external drive. This allows the
transmitter to be placed in an off state and still allow the
voltage regulator to operate. Refer to
TABLE 1-2:
1.5.9
RESET is an open-drain output pin. This pin tracks an
internal signal and indicates that the system voltage
has reached the proper level and stabilized. It also
operates as protection from brown-out conditions when
the supply voltage drops below a safe operating
voltage. The RESET is asserted immediately upon
entering the Powerdown mode.
DS22018C-page 8
Legend: x = don’t care
Note 1:
TXD
In
H
H
L
L
x
x
Table
RXD
Out
H
H
The FAULT/TXE is valid after approximately 25 µs after TXD falling edge. This is to eliminate false fault
reporting during bus propagation delays.
L
L
RESET
x
x
FAULT/TXE
1-2. The transmitter driver is disabled
FAULT/TXE TRUTH TABLE
LIN
GND
GND
V
V
V
V
I/O
BB
BB
BB
BB
BUS
Override
Thermal
OFF
OFF
OFF
OFF
ON
x
Figure
1-4.
External
Input
H
H
H
H
H
L
FAULT/TXE
Output
Driven
The FAULT/TXE also signals a mismatch between the
TXD input and the L
detect a bus contention. Since the bus exhibits a
propagation delay, the sampling of the internal
compare is debounced to eliminate false faults.
This
approximately 750 kΩ.
The FAULT/TXE pin sampled at a rate faster than every
10 µs.
H
H
H
L
L
x
Note 1: The FAULT/TXE pin is true (0) whenever
pin
2: FAULT/TXE is true (0) when V
FAULT, TXD driven low, LIN
V
OK
OK
OK, data is being received from the LIN
FAULT, Tranceiver in thermal shutdown
NO FAULT, the CPU is commanding the
tranceiver to turn off the transmitter driver
BB
the internal circuits have detected a short
or thermal excursion and have disabled
the L
and has disabled the L
has
(Note 1)
BUS
an
output driver.
BUS
internal
© 2008 Microchip Technology Inc.
level. This can be used to
Definition
pull-up
BUS
BUS
output driver.
REG
shorted to
resistor
not OK
BUS
of