NXP公司的TJA1021是LIN网络主/从协议控制器和LIN物理总线间接口器件,主要用在汽车中的子网络,波特速率从1kBd 到20kBd,并和LIN 2.1/SAE J2602兼容. TJA1021有非常低的电磁辐射(EME),高的电磁防卫度(EMI),输入电平和3.3V与5V器件兼容. TJA1021在睡眠状态有很低功耗,6KV的ESD保护电压(IEC 61000-4-2).本文介绍了TJA1021的全面特性,方框图, 典型应用电路以及AC特性测试电路.
The TJA1021 is the interface between the Local Interconnect Network (LIN) master/slave
protocol controller and the physical bus in a LIN. It is primarily intended for in-vehicle
sub-networks using baud rates from 1 kBd up to 20 kBd and is LIN 2.1/SAE J2602
compliant. The TJA1021 is pin-to-pin compatible with the TJA1020 with an improved
ElectroStatic Discharge (ESD) specification.
The transmit data stream of the protocol controller at the transmit data input (TXD) is
converted by the TJA1021 into a bus signal with optimized slew rate and wave shaping to
minimize ElectroMagnetic Emission (EME). The LIN bus output pin is pulled HIGH via an
internal termination resistor. For a master application an external resistor in series with a
diode should be connected between pin INH or pin VBAT and pin LIN. The receiver detects the data stream at the LIN bus input pin and transfers it via pin RXD to the microcontroller.
In Sleep mode the power consumption of the TJA1021 is very low. In failure modes the
power consumption is reduced to a minimum.
TJA1021主要特性:
General
LIN 2.1/SAE J2602 compliant
Baud rate up to 20 kBd
Very low ElectroMagnetic Emission (EME)
High ElectroMagnetic Immunity (EMI)
Passive behavior in unpowered state
Input levels compatible with 3.3 V and 5 V devices
Integrated termination resistor for LIN slave applications
Wake-up source recognition (local or remote)
Supports K-line like functions
Pin-to-pin compatible with TJA1020
Low power management
Very low current consumption in Sleep mode with local and remote wake-up
Protection mechanisms
High ESD robustness: 6 kV according to IEC 61000-4-2 for pins LIN, VBAT and
WAKE_N
Transmit data (TXD) dominant time-out function
Bus terminal and battery pin protected against transients in the automotive environment (ISO 7637)
Bus terminal short-circuit proof to battery and ground
Thermally protected
图1.TJA1021方框图
图2.TJA1021典型应用电路
图3.TJA1021 AC特性测试电路
