nxp 公司的tja1021 是lin 2.1/sae j2602收发器,是lin主/从协议控制器和lin物理总线间的接口,主要用在汽车中的子网络,波特速率从1 kbd 到 20 kbd,和lin 2.1/sae j2602兼容. tja1021具有非常低的电磁辐射(eme)和高的电磁免疫性(emi),输入电平和3.3v与5v兼容.本文介绍tja1021主要特性, 方框图, 典型应用图和交流特性测试电路图.
tja1021: lin 2.1/sae j2602 transceiver
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:
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
very low current consumption in sleep mode with local and remote wake-up
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典型应用图
图3.tja1021交流特性测试电路图
