ADI ADM3065EIEC静电放电(ESD)保护RS－485收发器解决方案 |电子通-应用新知，新电子的助推者电子通

ADI公司的ADM3065E是3.0V-5.5VIEC静电放电(ESD)保护半双工RS-485收发器,适合在多点总线传输线路中进行 50 Mbps 高速双向数据通信,完全符合现场总线^®标准.接触放电满足IEC 61000-4-2 ≥ ±12 kV ,空气放电满足IEC 61000-4-2 ≥ ±12 kV,而HBM ≥ ±30 kV,工作温度范围为−40℃ 至 +125℃ 及−40℃ 至 +85℃.主要用在工业现场总线,过程控制,楼宇自动化,现场总线网络和电机控制伺服驱动器和编码器.本文介绍了ADM3065E/ADM3066E主要特性,功能框图,半双工RS-485通信网络框以及评估板EVAL-ADM3065EEBZ和EVAL-ADM3065EEB1Z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 ADM3065E/ADM3066E feature a ¼ unit load input impedance, which allows up to 128 transceivers on a bus.

The 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 package, an 8-lead, 3 mm × 3 mm MSOP package, a 10-lead, 3 mm × 3 mm MSOP package, 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 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/ADM3066E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
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 package
8-lead and 10-lead MSOP packages

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.ADM3065E功能框图

图2.ADM3065E半双工RS-485通信网络框图

图3.ADM3065E信号和电源隔离25Mbps RS-485解决方案(简化框图)

评估板EVAL-ADM3065EEBZ和EVAL-ADM3065EEB1Z

The EVAL-ADM3065EEBZ and EVAL-ADM3065EEB1Z allow quick and easy evaluation of the ADM3065E 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-ADM3065EEBZ evaluation board has a footprint for the ADM3065EBRZ half duplex RS-485 transceiver in an 8-lead SOIC package. The EVAL-ADM3065EEB1Z evaluation board has a footprint for a full duplex RS-485 transceiver in an 8-lead MSOP package.

Complete specifications for the ADM3065E device are provided in the ADM3065E data sheet and should be consulted in conjunction with this user guide when using the evaluation board.

评估板EVAL-ADM3065EEBZ和EVAL-ADM3065EEB1Z主要特性:

Easy evaluation of ADM3065E 50 Mbps RS-485 transceiver
Board layouts for standard half duplex RS-485 footprints
8-lead, SOIC, ADM3065EBRZ (EVAL-ADM3065EEBZ)
8-lead, MSOP, ADM3065EBRMZ (EVAL-ADM3065EEB1Z)
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 and B bus pins
±12 kV contact discharge and ±12 kV air gap 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
EVALUATION KIT CONTENTS
EVAL-ADM3065EEBZ or EVAL-ADM3065EEB1Z
ADDITIONAL EQUIPMENT NEEDED
Oscilloscope
Signal generator or UART
3 V to 5 V supply