tja1051 NXP Semiconductors, tja1051 Datasheet - Page 4

• Manufacturer Part Number: tja1051
• Description: High-speed Can Transceiver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
6. Functional description
TJA1051_1
Product data sheet
6.1.1 Normal mode
6.1.2 Silent mode
6.2.1 TXD dominant time-out function
6.1 Operating modes
6.2 Fail-safe features
The TJA1051 is a high-speed CAN stand-alone transceiver with Silent mode. It combines
the functionality of the TJA1050 transceiver with improved EMC and ESD handling
capability. Improved slope control and high DC handling capability on the bus pins
provides additional application flexibility.
The TJA1051 is available in two versions, distinguished only by the function of pin 5:
The TJA1051 supports two operating modes, Normal and Silent, which are selectable via
pin S. See
conditions.
Table 3.
[1]
[2]
A LOW level on pin S selects Normal mode. In this mode, the transceiver is able to
transmit and receive data via the bus lines CANH and CANL (see
diagram). The differential receiver converts the analog data on the bus lines into digital
data which is output to pin RXD. The slope of the output signals on the bus lines is
controlled and optimized in a way that guarantees the lowest possible ElectroMagnetic
Emission (EME).
A HIGH level on pin S selects Silent mode. In Silent mode the transmitter is disabled,
releasing the bus pins to recessive state. All other IC functions, including the receiver,
continue to operate as in Normal mode. Silent mode can be used to prevent a faulty CAN
controller from disrupting all network communications.
A ‘TXD dominant time-out’ timer is started when pin TXD is set LOW. If the LOW state on
pin TXD persists for longer than t
lines to recessive state. This function prevents a hardware and/or software application
Mode
Normal
Silent
•
•
The version with pin 5 open is 100 % backwards compatible with the TJA1050
The version with a V
voltages down to 3 V
LOW if the CAN bus is dominant, HIGH if the CAN bus is recessive.
X = don't care
Operating modes
Table 3
Inputs
Pin S
LOW
LOW
HIGH
for a description of the operating modes under normal supply
Rev. 01 — 9 March 2009
IO
pin allows for direct interfacing to microcontrollers with supply
Pin TXD
LOW
HIGH
X
to(dom)TXD
[2]
, the transmitter is disabled, releasing the bus
Outputs
CAN driver
dominant
recessive
recessive
High-speed CAN transceiver
Figure 1
© NXP B.V. 2009. All rights reserved.
TJA1051
Pin RXD
active
active
active
for the block
[1]
[1]
[1]
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