ADI ADM3065EIEC静电放电(ESD)保护RS-485收发器解决方案

ADI公司的ADM3065E是3.0V-5.5V IEC ESD保护的RS-485收发器，其总线引脚上能经受住±12 kV接触放电，IEC 61000-4-2≥±12 kV 空气放电，HBM ≥ ±30 kV，数据速率50Mbps，完全符合Profibus®标准，扩展温度到125℃ ，半双工作，可连接多达128个节点到总线，主要用在工业现场总线，过程控制，建筑物自动化，Profibus网络以及马达控制伺服驱动和编码器。本文介绍了ADM3065E主要特性，框图和应用电路，以及评估板EVAL-ADM3061EEBZ和EVAL-ADM3061EEB1Z主要特性，电路图，材料清单和PCB设计图。

The ADM3065E is a 3.0 V to 5.5 V， IEC electrostatic discharge （ESD） protected RS-485 transceiver， allowing the device to withstand ±12 kV contact discharges on the transceiver bus pins without latch-up or damage. The ADM3066E features a VIO logic supply pin allowing a flexible digital interface capable of operating as low as 1.62 V.

The ADM3065E/ADM3066E are suitable for high speed， 50 Mbps， bidirectional data communication on multipoint bus transmission lines.

The ADM3061E/ADM3065E/ADM3066E feature a ¼ unit load input impedance， which allows up to 128 transceivers on a bus. The ADM3061E models offer all of the same features as the ADM3065E models， but at a low 500 kbps data rate suitable for operation over long cable runs.

The ADM3061E/ADM3065E/ADM3066E are half-duplex RS-485 transceivers， fully compliant to the Profibus® standard with increased 2.1 V bus differential voltage at VCC ≥ 4.5 V.

The RS-485 transceivers are available in a number of space-saving packages， such as a 10-lead， 3 mm × 3 mm LFCSP， an 8-lead， 3 mm × 3 mm MSOP， a 10-lead， 3 mm×3 mm MSOP，and an 8-lead， narrow body SOIC package. Models with operating temperature ranges of −40℃ to +125℃ and −40℃ to +85℃ are available.

Excessive power dissipation caused by bus contention or by output shorting is prevented by a thermal shutdown circuit. If， during fault conditions，a significant temperature increase is detected in the internal driver circuitry， this feature forces the driver output into a high impedance state.

The ADM3061E/ADM3065E/ADM3066E guarantee a logic high receiver output when the receiver inputs are shorted， open， or connected to a terminated transmission line with all drivers disabled.

ADM3065E主要特性：

TIA/EIA RS-485 compliant over full supply range

3.0 V to 5.5 V operating voltage range on VCC

1.62 V to 5.5 V VIO logic supply

ESD protection on the bus pins

IEC 61000-4-2 ≥ ±12 kV contact discharge

IEC 61000-4-2 ≥ ±12 kV air discharge

HBM ≥ ±30 kV

Full hot swap support （glitch free power-up/power-down）

High speed 50 Mbps data rate （ADM3065E/ADM3066E）

Low speed 500 kbps data rate for long cables （ADM3061E）

Full receiver short-circuit， open circuit， and bus idle fail-safe

Extended temperature range up to 125℃

Profibus compliant at VCC ≥ 4.5 V

Half duplex

Allows connection of up to 128 nodes onto the bus

Space-saving package options

10-lead， 3 mm × 3 mm LFCSP

8-lead and 10-lead MSOP

8-lead， narrow body SOIC package

ADM3065E应用：

Industrial fieldbuses

Process control

Building automation

Profibus networks

Motor control servo drives and encoders

图1.ADM3066E功能框图

图2.ADM3061E/ADM3065E功能框图

图3.ADM3061E/ADM3065E半双工RS-485通信网络图

图4.ADM3061E/ADM3065E信号和电源隔离25Mbps RS-485解决方案简图

图5.ADM3061E/ADM3065E信号和电源隔离50Mbps RS-485解决方案简图

评估板EVAL-ADM3061EEBZ和EVAL-ADM3061EEB1Z

The EVAL-ADM3061EEBZ and EVAL-ADM3061EEB1Z allow quick and easy evaluation of the ADM3061E 50 Mbps RS-485 transceiver with standard SOIC and MSOP footprints， respectively. The evaluation boards allow the input and output functions to be exercised without external components. Screw terminal blocks provide convenient connections for power and ground， digital input and output， and RS-485 signals. The evaluation boards can be powered by a standard configurable bench power supply within a 3 V to 5 V range.

The EVAL-ADM3061EEBZ evaluation board has a footprint for the ADM3061EBRZ half-duplex RS-485 transceiver in an 8-lead SOIC package. The EVAL-ADM3061EEB1Z evaluation board has a footprint for a full duplex RS-485 transceiver in an 8-lead MSOP package.

Complete specifications for the ADM3061E device are provided in the ADM3061E data sheet and should be consulted in conjunction with this user guide when using the evaluation board.

评估板EVAL-ADM3061EEBZ和EVAL-ADM3061EEB1Z主要特性：

Easy evaluation of the ADM3061E 50 Mbps RS-485 transceiver Board layouts for standard half-duplex RS-485 footprints

8-lead， SOIC， ADM3061EBRZ （EVAL-ADM3061EEBZ）

8-lead， MSOP， ADM3061EBRMZ （EVAL-ADM3061EEB1Z）

Power/ground connections through screw terminal block

3.0 V to 5.5 V operating voltage range on VCC

IEC ESD protection on the RS-485 A bus pin and B bus pin

±12 kV contact discharge and ±12 kV air discharge

Screw terminal blocks for logic input/output and RS-485 signals

Jumper-selectable enable/disable for RE and DE

Test points for measuring all signals

Resistors and footprints for termination and biasing networks

图6.评估板EVAL-ADM3061EEBZ外形图

图7.评估板EVAL-ADM3061EEB1Z外形图

图8.半双工RS-485两板点对点测试图

图9.评估板EVAL-ADM3061EEBZ电路图

图10.评估板EVAL-ADM3061EEB1Z电路图

评估板EVAL-ADM3061EEBZ材料清单：

评估板EVAL-ADM3061EEB1Z材料清单：

图11.评估板EVAL-ADM3061EEBZ PCB设计图：丝印

图12.评估板EVAL-ADM3061EEBZ PCB设计图：元件面/层1

图13.评估板EVAL-ADM3061EEBZ PCB设计图：层2