![](https://csdnimg.cn/release/download_crawler_static/87302810/bg14.jpg)
10 Detailed Description
10.1 Overview
The TCAN114x-Q1 is a CAN FD transceiver supporting data rates up to 5 Mbps meeting the high speed CAN
physical layer standards: ISO 11898-2:2016. The TCAN1145-Q1 and TCAN1146-Q1 support selective wake up
on dedicated CAN-frames. The devices can also wake up via remote wake up using CAN bus implementing the
ISO 11898-2:2016 Wake Up Pattern (WUP). The TCAN114x-Q1 supports 1.8 V, 3.3 V and 5 V processors using
V
IO
pin. The processor interface is through the SPI, RXD and TXD terminals. The devices have a Serial
Peripheral Interface (SPI) that connects to a local microprocessor for configuration. SPI supports clock rates up
to 4 MHz. The serial data output (SDO) pin can be configured as an interrupt output pin when the chip select pin
is high providing flexibility for system design.
The TCAN114x-Q1 provides CAN FD transceiver function: differential transmit capability to the bus and
differential receive capability from the bus. The device includes many protection features providing device and
CAN network robustness.
The CAN bus has two logical states during operation: recessive and dominant. See Figure 9-1 and Figure 9-2.
Recessive bus state is when the bus is biased to a common mode of about 2.5 V via the high resistance internal
input resistors of the receiver of each node on the bus across the termination resistors. Recessive is equivalent
to logic high and is typically a differential voltage on the bus of almost 0 V. Recessive state is also the idle state.
Dominant bus state is when the bus is driven differentially by one or more drivers. Current is induced to flow
through the termination resistors and generate a differential voltage on the bus. Dominant is equivalent to logic
low and is a differential voltage on the bus greater than the minimum threshold for a CAN dominant. A dominant
state overwrites the recessive state.
During arbitration, multiple CAN nodes may transmit a dominant bit at the same time. In this case, the differential
voltage of the bus is greater than the differential voltage of a single driver.
Transceivers have a third bus state where the bus terminals are weakly biased to ground via the high resistance
internal resistors of the receiver. See Figure 9-1 and Figure 9-2.
The TCAN114x-Q1 provides many enhanced features that are provided in the Section 10.3 section. Enhanced
features such as advanced bus fault detection, fail-safe, watchdog and providing a processor interrupt are
described in their specific subsections.
TCAN1144-Q1, TCAN1145-Q1, TCAN1146-Q1
SLLSF80A – OCTOBER 2019 – REVISED DECEMBER 2020
www.ti.com
20 Submit Document Feedback
Copyright © 2020 Texas Instruments Incorporated
Product Folder Links: TCAN1144-Q1 TCAN1145-Q1 TCAN1146-Q1