常用的RS485芯片简介

本文将简单介绍常用RS485 芯片

MAX48x系列芯片

The MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 are lo-poer transceivers for RS-485 and RS-422 munication. Each part contains one driver and onereceiver. The MAX483, MAX487, MAX488, and MAX489 feature reduced sle-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables,thus alloing error-free data transmission up to 250kbps.The driver sle rates of the MAX481, MAX485, MAX490,MAX491, and MAX1487 are not limited, alloing them to transmit up to 2.5Mbps.

These transceivers dra beteen 120µA and 500µA of supply current hen unloaded or fully loaded ith disabled drivers. Additionally, the MAX481, MAX483, and MAX487 have a lo-current shutdon mode in hich they consume only 0.1µA. All parts operate from a single 5V supply.

Drivers are short-circuit current limited and are protected against excessive poer dissipation by thermal shutdon circuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit.

The MAX487 and MAX1487 feature quarter-unit-load
receiver input impedance, alloing up to 128 MAX487/
MAX1487 transceivers on the bus. Full-duplex muni-
cations are obtained using the MAX488–MAX491, hile
the MAX481, MAX483, MAX485, MAX487, and MAX1487
are designed for half-duplex applications.

PIN 脚定义

 

MAX308x 系列

The MAX3080–MAX3089 high-speed transceivers for RS-485/RS-422 munication contain one driver and one receiver. These devices feature fail-safe circuitry,hich guarantees a logic-high receiver output hen the receiver inputs are open or shorted. This means that the receiver output ill be a logic high if all transmitters on a terminated bus are disabled (high impedance).
The MAX3080/MAX3081/MAX3082 feature reduced sle-rate drivers that minimize EMI and reduce reflec-tions caused by improperly terminated cables, alloing error-free data transmission up to 115kbps. The MAX3083/MAX3084/MAX3085 offer higher driver out-put sle-rate limits, alloing transmit speeds up to 500kbps. The MAX3086/MAX3087/MAX3088’s driversle rates are not limited, making transmit speeds upto 10Mbps possible. The MAX3089’s sle rate isselectable beteen 115kbps, 500kbps, and 10Mbps by driving a selector pin ith a single three-state driver.

These transceivers typically dra 375µA of supply current hen unloaded, or hen fully loaded ith the drivers disabled.

All devices have a 1/8-unit-load receiver input impedance that allos up to 256 transceivers on the bus. The MAX3082/MAX3085/MAX3088 are intended for half-duplex munications, hile the MAX3080/MAX3081/MAX3083/MAX3084/MAX3086/MAX3087 are intended for full-duplex munications. The MAX3089 is selectable beteen half-duplex and full-duplex operation. It
also features independently programmable receiver and transmitter output phase via separate pins.

Pin 脚定义

 MAX3443E

The MAX3443E fault-protected RS-485/RS-422 transceiver features ±60V protection from signal faults on munication bus lines. Each device contains one differential line driver ith three-state output, and one differential line receiver ith three-state input. The 1/4-unit-load receiver input impedance allos up to 128 transceivers on a single bus. The device operates from a 5V supply at data rates up to 10Mbps. True fail-safe inputs guarantee a logic-high receiver output hen the receiver inputs are open, shorted, or connected to an idle data line.

Hot-sap circuitry eliminates false transitions on thedata cable during circuit initialization or connection to a live backplane. Short-circuit current limiting and thermal shutdon circuitry protect the driver against excessive poer dissipation, and integrated ±15kV ESD protection eliminates costly external protection devices.

The MAX3443E is available in 8-pin SO and PDIP packages, and is specified over mercial, industrial, and automotive temperature ranges.

封装方式及工作环境温度列表

 Pin脚定义

 华之美半导体Max485兼容芯片

是一款国产RS485芯片，应用于 RS-485 和 RS-422通信系统的收发芯片。MAX485 传输和接收的数据传输率可高达 2.5Mbps。485 为半双工型。，485 有驱动使能(DE)和接收使能(RE)管脚，当关闭时，驱动和接收输出为高阻。MAX485 具有失效保护功能，在处于接收状态时，输入端开路或短路接收器输出为高电平。

 

 ISL32705E

The ISL32705E is a galvanically isolated, full-duplex differential bus transceiver, designed for bidirectional data transmission meeting the RS-485 and RS-422 standards for balanced munication. All bus terminals are protected against ±7kV ESD strikes ithout latch-up.

The device uses Giant Magoresistance (GMR) as isolation technology. A unique ceramic/polymer posite barrier provides excellent isolation and nearlyunlimited barrier life.

The part is available in a 16 Ld ide-body SOIC package providing true 8mm creepage distance.

The ISL32705E delivers a minimum of 1.5V into a 54Ω differential load for excellent data integrity over long cable lengths.
The device is patible ith 3V and 5V input supplies, alloing an interface to standard microcontrollers ithout additional level shifting.

Current limiting and thermal shutdon features protect against output short-circuits and bus contention that may cause excessive poer dissipation. Receiver inputs feature a “fail-safe if open” design, ensuring a logic high R-output if A/B are floating.

M7517xP 系列

Each of the M75176 to M75179 is a semiconductor IC ith a built-in differential driver and a built-in differential receiver both of hich meet the EIA standards RS-422A and RS-485.

The M75176P to M75179P are line interface ICs hich meet EIA standards RS-422A and RS-485, and are suitable for long-distance, high-speed data transmission.

The M75176P is designed to connect the driver circuit output and the receiver input to each other internally, and serves as a line transceiver. The M75177P/M75178P is designed to connect the receiver circuit output and the driver circuit input internally, and serves as a line repeater. The M75177P and M75178P enter the output enabled state ith active “H” and active “L”, respectively. The M75179P is equipped ith abuilt-in differential driver and a built-in differential receiver. It does not have an output control input pin but its output im-pedance at the poer-OFF time goes high.

Pin脚定义

 

 

 

 SN65HVD11-HT

The SN65HVD11 bines a 3-state differential line driver and differential input line receiver that operates ith a single 3.3-V poer supply. It is designed for balanced transmission lines and meets or exceeds ANSI TIA/EIA-485-A and ISO 8482:1993, ith the exception that the thermal shutdon is removed. This differential bus transceiver is a monolithic integrated circuit designed for bidirectional data munication on multipoint bus-transmission lines. The driver and receiver have active-high and active-lo enables, respectively, that can be externally connected together to function as direction control.

The driver differential outputs and receiver differential inputs connect internally to form a differential input/ output (I/O) bus port that is designed to offer minimum loading to the bus hen the driver is disabled or V CC = 0.

Pin脚定义

 

 SN65HVD3082E/SN75HVD3082E

These devices are half-duplex transceivers designed for RS-485 data bus orks. Poered by a 5-V supply, they are fully pliant ith TIA/EIA-485A standard. With controlled transition times, these devices are suitable for transmitting  data  over  long  tisted-pair  cables.
SN65HVD3082E and SN75HVD3082E devices are optimized for signaling rates up to 200 kbps.
SN65HVD3085E is suitable for data transmission up to 1 Mbps,  hereas  SN65HVD3088E  is  suitable  for applications requiring signaling rates up to 20 Mbps.These devices are designed to operate ith very lo supply current, typically 0.3 mA, exclusive of the load.When in the inactive shutdon mode, the supply current drops to a fe nanoamps, making these devices ideal for
poer-sensitive applications.

The ide mon-mode range and high ESD protection levels of these devices make them suitable for demanding applications such as energy meter orks, electrical inverters, status/mand signals across tele racks,cabled chassis interconnects, and industrial automation orks here noise tolerance is essential. These devices match the industry-standard footprint of SN75176.Poer-on reset circuits keep the outputs in a high-impedance state until the supply voltage has stabilized. A thermal shutdon function protects the device from
damage  due  to  system  fault  conditions.  The SN75HVD3082E is characterized for operation from 0°C to 70°C and SN65HVD308xE are characterized for operation from −40°C to 85°C air temperature.

 

 SP3485

The SP3485 device is a +3.3V lo poer half-duplex transceiver that meets the specifica-
tions of the RS-485 and RS-422 serial protocols. This device is pin-to-pin patible ith
the Exar SP48?, SP483 and SP485 devices as ell as popular industry standards. The
SP3485 features the Exar BiCMOS process, alloing lo poer operation ithout sacrificing
performance. The SP3485 can meet the electrical specifications of the RS-485 and RS-422
serial protocols up to 10Mbps under load.

Pin脚定义